PUERTO RICAN WOODS Their Machining, Seasoning and Related ... · Their Machining, Seasoning and...

PUERTO RICANWOODSTheir Machining, Seasoningand Related Characteristics

Agricuiture Handbook No. 205

U.S. DEPARTMENT OF AGRICULTURE • F O R E S T S E R V I C E

PUERTO RICAN WOODS

Their Machining, Seasoningand Related Characteristics

by

FRANKLIN R. LONGWOOD

Northeastern Forest Experiment Station, Forest Service;formerly at the Tropical Forest Research Center

of the Forest Service in Puerto Rico

Growth Through Agricultural Progress

U.S. DEPARTMENT OF AGRICULTURE

Agriculture Handbook No. 205

FOREST SERVICE

Issued November 1961

ACKNOWLEDGMENTS

Studies of the type described in the following pages require the cooperationand assistance of many individuals and organizations. The writer was par-ticularly fortunate in this regard and takes this opportunity to express hisappreciation to all those to whom he is indebted.

II

Special acknowledgment and thanks are due Raul Coronado Ybarra andErnesto Goytia Olmedo for their indispensable assistance throughout thestudy; J. T. Drow, R. F. Kukachka, E. C. Peck, and E. L. Peterson of the U.S.Forest Products Laboratory for their assistance in planning the research pro-gram, in computation of data, and manuscript review; E. M. Davis of theForest Products Laboratory for assistance in developing machining andgrading techniques; Dr. Elbert L. Little, Jr., for his careful technical review;the Commonwealth Forest Service of Puerto Rico for supplying part of thetest material; Dr. F. R. Wadsworth, Research Center Leader at Rio Piedras,for his counsel and support; Antonio Atiles of the University of Puerto RicoAgricultural Extension Service for the many excellent photographs; and Dr.G. N. Wolcott,, Entomologist at the University of Puerto Rico AgriculturalExperiment Station, for conducting tests on the resistance of Puerto Ricanwoods to dry-wood termites.

ContentsIntroduction- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

PART 1Determination of machining characteristics and re-

lated properties- - - - - - - - - - - - - - - - - - - - - - - - - - - -Selection of sample material - - - - - - - - - - - - - - -Air-seasoning characteristics - - - - - - - - - - - - - -

Procedure - - - - - - - - - - - - - - - - - - - - - - - - - - - -Results- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Tendency to warp- - - - - - - - - - - - - - - - - - - - - - - - - - - - -P r o c e d u r e - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -R e s u l t s - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Physical properties - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Specific gravity and moisture content-----------Weight per cubic foot - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Shrinkage - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Machining properties --------------------------------------------Procedure - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Selection of test material - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Grading - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Planing - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -S h a p i n g - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -T u r n i n g - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -B o r i n g - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Mortising - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Sanding - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Related properties - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Screw splitting - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Resistance to dry-wood termites --------------------

Summary and conclusions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Timber descriptions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -A c h i o t i l l o - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -A g u a c a t i l l o - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -A l g a r r o b o - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Almácigo - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Almendra - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -A u s u b o - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -C a i m i t i l l o - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Caimitillo verde - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Caoba hondureña - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Capá blanco - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Capá prieto - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Caracol i l lo - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Casuarina - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Cedro hembra - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -C e i b a - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

PART 2

Page1

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Timber descriptions— ContinuedCucubano - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -C u p e y - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Espino rubial - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Eucalipto - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Granadillo - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -G u a b a - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -G u a j ó n - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -G u a m á - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -G u a n o - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Guarnguao - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Guayabota - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Higüerillo - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Jácana - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Jagua - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Jagüey blanco - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -J o b o - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Jusillo - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Laurel amarillo - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Laurel avispillo - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Laurel geo - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Laurel prieto - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Laurel sabino - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Mago - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Mamey - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Mango - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -María - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Maricao - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Masa - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Moca - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Motillo - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Negra lora - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Nemocá - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Nuez moscada - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Palo colorado - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Palo de hueso - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Palo de matos - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Panapén - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Roble blanco - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Samán - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Tabaiba - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Tabonuco - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Teca - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Ucar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Yagrumo hembra - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Yagrumo macho - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Bibliography - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Index to timber descriptions ----------------------------------

III

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For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington 25, D.C. Price 65 cents

INTRODUCTIONMore than 500 species of trees are indigenous to

the forests of Puerto Rico, ranging from balsa,which produces the lightest commercial woodknown, to lignumvitae, one of the heaviest and oneof the most valuable of all woods. Yet fewer thanone-third of these tree species ordinarily reachsaw-log size. Moreover, only 52 of this number,plus 8 introduced species, provide the bulk of allnative-grown saw-log size material available fordomestic and commercial use. The others eithermature below saw-log size or occur too infre-quently for commercial use. A few high-qualitywoods owe their scarcity and small size to pastheavy cutting because of their good qualities.Still others are seldom used because they are dif-ficult to season or machine or their propertiesand uses are poorly known. This does not pre-clude the possibility that other species will becomemerchantable when more is known about theircharacteristics. and uses.

Most of the native woods are available onlyin limited quantities and none are sufficientlyabundant for export. Nevertheless, many ofthem have far more utility and value than theircurrent use would indicate.”

At present fewer than a dozen of these treespecies are utilized to any appreciable extent. forlumber and similar products. The majority eitherare not used at all or are used principally forfuel, charcoal production, or other low-valueproducts.

This improvident use of a relatively scarce re-source cannot be attributed to a lack of marketsfor wood. Every year some 80 to 90 million boardfeet of lumber and other wood products are re-quired to meet the expanding requirements of theisland. About 1 percent of this volume, some850,000 board feet, is provided by the local forests;the remainder is imported from the United States,Mexico, and other Caribbean areas. Immensequantities of low-grade but relatively expensivepitch pine and western fir are brought in annually,yet are inferior in some ways to a number ofvirtually unused native woods.

Relatively little is known about the characteris-tics and properties of the local woods or the usesfor which they are suitable. This is in contrast to

1 Additional information about nearly all these treespecies, including descriptions, drawings. ranges. andother common names. is included in the followingpublication :

Little, Elbert L., Jr., Wadsworth, Frank H., andMarrero, José. Arboles Communes de Puerto Rico eIslas Vírgenes. University of Puerto Rico. (inpress. )

the relatively detailed and complete knowledgeabout the imported woods. Probably no otherfactor contributes more toward the neglect andmisuse of native woods.

Another factor contributing to the neglect ofnative woods is the erroneous but neverthelesswidespread belief that only heavy, dark-coloredwoods are strong and durable, machine well, orposses attractive figure. Both Honduras ma-hogany and cedro hembra illustrate the fallacy ofthis idea. Although moderately light in color andweight, both woods are rated among the all timefavorites for cabinetmaking and other exactinguses. Furthermore, most of the imported woods,especially pitch pine, western fir, baboen, andAfrican mahogany, are also light in weight andcolor but nevertheless have good utility for a mul-titude of uses.

The utility of Puerto Rican woods is frequentlydepreciated by a combination of improper season-ing, poor handling, and unsuitable machiningpractices. This condition results not so muchfrom neglect or unwillingness to employ properpractices but rather from a scarcity of knowledgein these fields. Lack of information concerningthe drying, handling, and machining properties ofthese woods has been an obstacle to wider use.Some of the everyday operations in utilizing localwoods hare been under investigation at the Tropi-cal Research Center for several years. This hand-book summarizes the information that should beuseful to the person using or contemplating theuse of native woods for domestic or commercialpurposes.

The material presented is divided into twoparts: Part 1 describes the procedures and sum-marizes the results of recent determinations ofwood properties at the Tropical Forest ResearchCenter in Rio Pie&as, Puerto Rico. Of the prin-cipal saw-log species of Puerto Rico, 56 were in-cluded in the tests, along with plantation-grownteak, eucalyptus, and casuarina. Forest-grownHonduras mahogany from Mexico, also plantedextensively on the island, was included for com-parison. These native species and planted exotics(table 1) represent the bulk of all saw-log-sizetimber growing on the island.1

Fourteen of the 60 woods as well as a few others fromPuerto Rico are described further in the followingpublication :

Longwood, Franklin R. Present and PotentialTimhers of the Caribbean— With Special Reference tothe West Indies, the Guianas, and British Honduras.U.S. Dept. Agr. Handbook No. 207. 1961.

1

2 U.S. DEPT. OF AGRICULTURE HANDBOOK NO. 205

TABLE 1.— The principal native and plantation-grown saw-log woods of Puerto Rico

Common name in PuertoRico

A c h i o t i l l o - - - - - - - - - - - - - - - - - - - - - -Aguacatillo - - - - - - - - - - - - - - - - - - - - - - -Algarrobo - - - - - - - - - - - - - - - - - - - - - - - -Almacigo 1

-- - - - - - - - - - - - - - - - - - - - - - -Almendra 1 2

- - - - - - - - - - - - - - - - - - - - -

A u s u b o - - - - - - - - - - - - - - - - - - - - - - - - -Caimiti l lo - - - - - - - - - - - - - - - - - - - - - - - -Caimitillo verde --------------------Caoba hondureña 2

------------

Capá blanco 1-- - - - - - - - - - - - - - - - - - -

Capá prieto 1-- - - - - - - - - - - - - - - - - - - -

Caracol i l lo - - - - - - - - - - - - - - - - - - - - - - -Casuarina 2 3

- - - - - - - - - - - - - - - - - - - - -Cedro hembra - - - - - - - - - - - - - - - - - - - -

C e i b a - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Cucubano - - - - - - - - - - - - - - - - - - - - - - - -C u p e y - - - - - - - - - - - - - - - - - - - - - - - - - - - -Espino rubial - - - - - - - - - - - - - - - - - - - - -Eucalipto 1 2 3

- - - - - - - - - - - - - - - - - -Granadil lo - - - - - - - - - - - - - - - - - - - - - - - -

Guaba 2 - - - - - - - - - - - - - - - - - - - - - - - - - - -

G u a j ó n - - - - - - - - - - - - - - - - - - - - - - - - - -G u a m á - - - - - - - - - - - - - - - - - - - - - - - - - - -Guano - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Guaraguao - - - - - - - - - - - - - - - - - - - - - - - -

Guayabota - - - - - - - - - - - - - - - - - - - - - -Higüerillo 1

-- - - - - - - - - - - - - - - - - - - - - -Jácana - - - - - - - - - - - - - - - - - - - - - - - - - - - -Jagua - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Jagüey blanco - - - - - - - - - - - - - - - - - - - -

J o b o - - - - - - - - - - - - - - - - - - - - - - - - - - - -Jusillo - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Laurel amarillo ------------------Laurel avispillo ------------------Laurel geo - - - - - - - - - - - - - - - - - - - - - - - - -

Laurel prieto - - - - - - - - - - - - - - - - - - - - -Laurel sabino ---------------------M a g o - - - - - - - - - - - - - - - - - - - - - - - - - - -Mamey 1

- - - - - - - - - - - - - - - - - - - - - - - - - -Mango 2

- - - - - - - - - - - - - - - - - - - - - - - - - - -

María - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Maricao - - - - - - - - - - - - - - - - - - - - - - - - - -M a s a - - - - - - - - - - - - - - - - - - - - - - - - - - - - -M o c a - - - - - - - - - - - - - - - - - - - - - - - - - - -Motil lo - - - - - - - - - - - - - - - - - - - - - - - - - - -

Negra lora - - - - - - - - - - - - - - - - - - - - - - - - -Nemocá - - - - - - - - - - - - - - - - - - - - - - - - - - -Nuez moscada --------------------Palo colorado - - - - - - - - - - - - - - - - - - - - -Palo de hueso --------------------

Palo de matos -------------------Panapén 2

-- - - - - - - - - - - - - - - - - - - - - - - -Roble blanco - - - - - - - - - - - - - - - - - - - - - -Samán 1 2

- - - - - - - - - - - - - - - - - - - - - - - - -Tabaiba - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Tabonuco - - - - - - - - - - - - - - - - - - - - - - - -Teca 2 3

- - - - - - - - - - - - - - - - - - - - - - - - - - - - -Ucar 1

-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Yagrumo hembra ----------------Yagrumo macho -----------------

Scientific name English name

Alchornea latifolia Sw - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Meliosma herbertii Rolfe - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Hymenaea courbaril L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Bursera simaruba (L.) Sarg - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Terminalia catappa L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Manilkara bidentata (A. DC.) Chev -----------------------------Micropholis chrysophylloides Pierre ------------------------------M. garciniaefolia Pierre - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Swietenia macrophylla King ----------------------------------------

Petitia domingensis Jacq - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Cordia alliodora (Ruiz & Pav.) Oken ---------------------------Homalium racemosum Jacq - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Casuarina equisetifolia L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Cedrela odorata L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Ceiba pentandra (L.) Gaertn ---------------------------------------

Guettarda laevis Urban - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Clusia rosea Jacq - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Zanthoxylum martinicense (Lam.) DC --------------------------Eucalyptus robusta J. E. Smith -----------------------------------Buchenavia capitata (Vahl) Eichl ---------------------------------

Inga vera Willd - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Beilschmiedia pendula (Sw.) Benth. & Hook. f--------------Inga laurina (Sw.) Willd - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Ochroma pyramidale (Cav.) Urban ------------------------------Guarea trichilioides L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Eugenia stahlii (Kiaersk.) Krug & Urban--------------------Vitex divaricata Sw - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Pouteria multiflora (A. DC.) Eyma ------------------------------Genipa americana L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Ficus laevigata Vahl - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Spondias mombin L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Calycogonium squamulosum Cogn -------------------------------Nectandra sintenisii Mez - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -N. coriacea (Sw.) Griseb - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Ocotea leucoxylon (Sw.) Maza -------------------------------------

Nectandra membranacea (Sw.) Griseb --------------------------Magnolia splendens Urban - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Hernandia sonora L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Mammea americana L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Mangifera indica L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Calophyllum brasiliense Camb ------------------------------------Byrsonima coriaceum (Sw.) DC ----------------------------------Tetragastris balsamifera (Sw.) Kuntze-------------------------Andira inermis (W. Wright) H.B.K ----------------------------Sloanea berteriana Choisy -------------------------------------------

Matayba domingensis (DC.) Radlk ------------------------------Ocotea spathulata Mez - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -O. moschata (Meissn.) Mez - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Cyrilla racemiflora L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Haenianthus salicifolius Griseb -----------------------------------

Ormosia krugii Urban -------------------------------------------------------Artocarpus altilis (Parkinson) Fosberg ------------------------Tabebuia heterophylla (DC.) Britton ----------------------------Pithecetlobium saman (Jacq.) Benth ----------------------------Sapium laurocerasus Desf - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Dacryodes excelsa Vahl - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Tectona grandis L. f - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Bucida buceras L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Cecropia peltata L - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Didymopanax morototoni (Aubl.) Dec. & Planch---------

West Indian locust, courbaril.Gumbo-limbo.Indian-almond.Balata, bulletwood.

Honduras mahogany, Mexicanmahogany.

Capa.

Casuarina.Spanish-cedar, Central Ameri-

can cedar.Silk-cotton tree.

Martinique prickly-ashBeakpod eucalyptus.

Balsa.American muskwood.

White fiddlewood.

Genipa.Shortleaf fig.Yellow mombin.

Jamaica nectandra.

Mango.Mamey, mammee-apple.

Santa Maria.

Cabbage angelin, angelin.

Swamp cyrilla.

Breadfruit.“White-cedar.”Rain-tree.

Candlewood, gommier.Teak.Oxhorn bucida.Trumpet-tree.Matchwood.

1 Sample material limited to 2 or 3 sample logs.2 Introduced species.

3 Plantation grown.

PUERTO RICAN WOODS 3

The tests of the 60 species included determina-tions of specific gravity and weight per cubicfoot, shrinkage, seasoning characteristics, ma-chineability, and resistance to dry-wood termites.The density and shrinkage values are based onwell-prescribed conditions and procedures whichcan be repeated.for each species.

These data then are significantThe opposite is true for the

other tests, in which seasoning conditions, ma-chining techniques, and other factors affect thenumerical ratings of the different species. Inthese tests, the comparative ratings of the dif-ferent woods are more important that the numeri-cal grades assigned on the basis of the test results.

Certain other characteristics or properties, suchas stability after manufacture, weathering char-acteristics, permeability to preservative!, and dur-ability in or near the ground, are also Importantin certain uses but were not considered in thestudy. The purpose of this series of tests was toprovide a broad general knowledge of certain im-portant characteristics of the principal lumberspecies.

The study was not intended to develop detailedand complete knowledge of the different aspectsof the uses of the different woods but rather toevaluate some of their more important propertiesso that the potential producer or user can eithergrow or utilize them more efficiently. It is onlya beginning; much more needs to be done beforethe different woods can be most efficiently utilizedin the local economy.

Part 2 contains a brief summary of the im-portant characteristics and properties of the same60 timbers of potential importance in Puerto Rico.Figures showing representative plainsawed andquartersawed sections are also included for eachspecies.2

2 Photographs were taken and processed by AntonioAtiles of the University of Puerto Rico Extension Service,using specimens prepared at the Wood Testing Labora-tory in Rio Piedras.

Timber descriptions are based on the tests de-scribed in Part 1, and on other observations madeover several years at the Wood Testing Labora-tory in Rio Piedras. Physical descriptions of thetimbers are based on the average for several hun-dred specimens prepared in the laboratory fromtrees cut in the local forests. Information on con-version, seasoning, green and air-dry3 weight,shrinkage, machining properties, and certain in-sect and fungous enemies was derived from testsand observations in the Laboratory. This wassupplemented by local knowledge of the trees andtheir woods and a limited amount of referencematerial. Data on resistance to dry-wood ter-mites was provided by Dr. G. N. Wolcott of theUniversity of Puerto Rico from results of pre-vious research, and from current studies usingwood specimens prepared at the Wood TestingLaboratory.

Recommended uses are listed for each specieson the basis of its physical and mechanical char-acteristics. Since a number of the woods ap-peared to be comparable to other well-knownwoods, they were recommended for similar uses.Wherever possible, acceptable local uses are alsoshown for those species currently being utilized.This information is supplemented by listing cur-rent uses for those species or for other closely re-lated species growing in other areas of the Carib-bean. In some instances, recommendations byreliable sources outside the Caribbean area wereincluded, but only if they conformed with theknown characteristics of the wood. Additionalresearch and experience with the different, specieswill undoubtedly add many specific uses to thosementioned in the text.

3 All air-dry weights were calculated on the basis of 15percent moisture content.

PART 1. DETERMINATION OF MACHININGCHARACTERISTICS AND RELATED PROPERTIES

Selection of Sample MaterialAll sample material required for determinations

of shrinkage, specific gravity, air seasoning, ma-chining properties, and screw splitting, was takenfrom one set of sample logs for each species. Ex-cept as noted, all sample material was obtainedfrom five or more typical saw-log-size sampletrees of each species. These trees were selected atrandom from the local forests or plantations.One sample log, 9 feet 6 inches long, was cutfrom each sample tree, starting at a point 8 feetabove the butt swell. For certain species thatnormally have clear boles less than 16 feet long,the sample logs were cut from the center of themerchantable part of the trees. The first 8-foot, section of some sample trees was also se-lected for use in the machining and air-seasoningtests when insufficient volume was available in theregular sample logs. These are referred to aslumber logs.

The logs were flatsawed into random-width lum-ber in a small circular sawmill. Boards were sup-

Air-SeasoningLumber and other wood products cut from saw

logs are generally kiln-dried or air-seasoned priorto use. The time required for seasoning and thetype and severity of defects occurring during theprocess vary greatly among woods and are of pri-mary importance in their utility. A wood may beattractive and may possess very satisfactory ma-chining and mechanical characteristics, yet. it mayhare limited use because of poor seasoning charac-teristics. Other things being equal, woods thatseason readily and with a minimum of degradeare preferred. With good control, most woodscan be kiln-dried with less degrade than occursin air-seasoning. However, lumber generally ispartially air-seasoned before it is put into thekiln. Considerable warping and checking in thepreliminary air-seasoning are sometimes improvedduring the kiln-drying process. Consequently,the air-seasoning characteristics of a wood are im-portant whether it is to be kiln-dried or seasonedonly in the open.

The tests involved two parts: one was a studyof the time required to air-season conventionally

4

posed to be cut 1 1/8 inch-thick, but were more often1¼ inch thick because of the extremely poor con-dition of the mill. Six sample boards were se-lected from each sample log during sawing.Four of these were typical flatsawed boards 4inches or more wide, one from each of the fourquadrats of the log, for use in specific gravityand shrinkage tests. One board was taken fromthe periphery, one near the pith, and two fromthe area of representative or average growth. Inaddition to the above, two 8½ -inch boards wereselected from opposite quadrats of each samplelog for use later in warp tests.

The lumber logs cut from the butt sections ofsome trees were sawed into flat-grain lumber inthe same manner as the sample lops but no sampleboards were selected. The selection and prepara-tion of the lumber and test material for the vari-ous tests and the procedures followed in thesetests are described in the later sections dealingwith the individual subjects.

Characteristicspiled green lumber and of the type and frequencyof defects occurring during the process; the otherwas a warp-test study in which 4-foot boards wereallowed to season without restraint of any kindso that the natural warping tendencies of thedifferent woods could be observed and measured.

PROCEDUREPreparation of Lumber

Lumber used in the air-seasoning tests was typi-cal random-width commercial-quality flat-grainboards, 1 1/8 inches to 1¼ inches thick and 8 feet 2inches long. All material was first en&trimmedto exact size and then dipped for 3 minutes inan aqueous solution containing benzene hexa-chloride and a mild fungicide to prevent insectattack and development of molds and sap-stainingfungi. After dipping, the boards were end-coatedand piled under cover for air-seasoning. All de-fects evident in the boards at, the time of pilingwere marked to distinguish them from defectsdeveloping during seasoning.


FIGURE 1.— Puerto Rican woods stacked for air-seasoning at the Wood Testing Laboratory in Rio Piedras, Puerto Rico.

The lumber was seasoned on specially preparedpile foundations in sheds open on three sides andpartially open on the fourth side. The pile foun-dations, 6 feet wide by 8 feet 2 inches long, werebuilt on cement-block supports. Supports werecentered at 2-foot intervals in 3 rows running thelength of the pile, requiring 15 supports for eachpile (fig. 1). Six-inch square timbers were placedon the 3 tiers of supports lengthwise and 4- by4-inch cross members positioned over them at 2-foot intervals. Piles were spaced 4 feet apart toallow adequate air circulation and working space.This type of foundation meets the accepted stand-ards for good air-seasoning practices. None ofthe subsequent warpage was attributed to faultypile foundations.

Stacking Lumber

The lumber was piled as shown in figure 1,leaving ½ -inch spacing between boards up to 8½inches wide and l-inch spacing between widerboards. Dry softwood stickers, 25/32 inch thickand 1¾ inches wide, were placed between each

layer of boards at 24-inch intervals directly abovethe pile supports and cross members. Piles werestacked 8 feet high. They were topped off withsurplus lumber and anchored in place with 300 to400 pounds of concrete weights.

Determination of Moisture Content

To record the drying rate of each species, itwas necessary to determine the moisture contentat the start of drying, at frequent intervals duringthe seasoning process, and finally when the lumberwas air-dry. For this, six sample boards, pre-dominantly heartwood, were prepared for eachspecies. These samples, 19 inches long, were cutfrom the center of green boards, and a waferapproximately 1½ inches long was sawed fromeach end for determining their initial green mois-ture content and ovendry weight.

The 16-inch samples were then end-coated withplastic-asphalt roof coating, weighed to the near-est 2 grams, and placed in the lumber piles onspecially prepared cradles (fig. 2).


These pile samples were removed from the lum-ber stacks at 2-week intervals, weighed, and re-turned to the piles. The moisture content of eachsample was calculated each time, according to thefollowing formula :Moisture content in percent =

current weight— calculated ovendry weightcalculated ovendry weight × 100

When no loss was recorded over a 4-week period,the samples were considered to have been air-dryat the start of the 4-week period. A final checkon the air-dry moisture content was then calcu-lated by means of five or more cross sections cutfrom each pile sample.

Measurement of Drying DefectsAfter each wood became air-dry, 50 or more

air-dry boards were inspected for the presence4 Forest Service. Wood Handbook. U.S. Dept. Agr.

Handb. 72, 479–490. 1955.

and severity of warping and checking that had de-veloped during seasoning. Seasoning defectswere rated on this basis : A = none, B = very slight,C = slight, D = moderate, E = severe, and F = verysevere.

The use of badly warped lumber requires in-creased labor, and it causes waste in manufacture.Warp may also cause trouble later. Warpedboards usually require heavy planing or mustbe cut into short or narrow pieces, or both.

Warp was separated into four categories: cup,twist, crook, and bon-. The first two are the mostserious. Cup is defined as “a deviation flatwisefrom a straight line across the width of theboard”; twist is “a distortion caused by the turn-ing or winding of the edges of a board so thatthe four corners of any face are no longer in thesame plane”; bow is “the distortion in a boardthat deviates from flatness lengthwise but notacross its face”: crook is “a distortion of a boardin which there is a deviation edgewise from astraight line from end to end of the board.” 4

FIGURE 2.— Sample boards for determining the moisture content of stacked lumber were placed in the stacks in speciallyF–495310

fitted cradles.


Checking may occur either on the surface ofboards or at the ends. It may be superficial andeasily removed during planing or trimming, but itmay be so deep as to make the piece worthless.

RESULTS

Seasoning Time and FinalMoisture Content

Most of these woods were thoroughly air-seasoned in 6 months or less, some requiring only3 to 4 months and others 10 months or longer.Table 2 shows the approximate number of weeksrequired to air-season the different woods and the

final air-dry moisture content reached when 1 1 / 8 -to 1¼ -inch lumber is piled for seasoning undercover in the San Juan area. These figures repre-sent the average for each wood, and they varyslightly according to the density of individualpieces of a species; particularly, dense specimensof any wood will normally have a somewhat lowermoisture content than those that are lighter thanaverage. The final air-dry moisture contentvalues range considerably among the differentwoods, from a low of 16 percent for seven differ-ent woods to a high of 22 percent. for mamey. Incomparison, thoroughly air-dry Hondurasmahogany used in the machining tests containedan average moisture content of 16 percent.

TABLE 2 .— Approximate time to air-season green 1 1/8 - t o 1¼ -inch rough lumber in San Juan, Puerto Rico

RAPID

Species

GuabaCaimitillo verdeAlmendraYagrumo hembraYagrumo macho

Laurel sabinoGranadilloRoble blancoNuez moscadaMasa

Capá blancoCedro hembraCaimitilloAusuboTabonuco

GuamáTecaEspino rubialMagoAlmácigo

MODERATE SLOW

Time toseason

Weeks Percent

Finalmoisturecontent

Species

GuanoCeibaNemocáSamánEucalipto

GúayabotaAlgarroboJusilloCucubanoLaurel amarillo

Laurel avispilloLaurel prietoUcarCaracolilloCupey

Palo de huesoJoboTabaibaMaraicao

Time toseason

Weeks

Finalmoisturecontent

Percent

Jagüey blancoPalo de matesMariaJácanaNegra lora

CasuarinaLaurel geoMameyMangoAchiotillo

AguacatilloMocaPanapénMotilloCapá prieto

1 Required more than 1 year to air-dry under test conditions.

JaguaGuaraguaoPalo coloradoGuajónHigüerillo 1


Some variations in the final air-dry moisturecontent. values occur during different parts of theyear in the San Juan area. Consequently, themoisture contents presented in table 2 are ap-proximate and may vary for some woods as much

sult, would have reduced the amount and severityof surface checking. But warping would not havebeen materially changed. Conversely, more openpiling and increased air movement probably wouldhave reduced the drying time and increased

as 3 to 4 percent according to season. However, it checking.is evident that most Puerto Rican woods will air-season to between 16 and 19 percent in the San

The proximity of one species to another in the

Juan area. In general, it should be safe to assumepiles, or its location within the pile, may have

that lumber is air-dry in the San Juan area wheninfluenced the drying rate of some woods. And

all samples show 18 percent or less moisture con-the season when the wood is dried may be of even

tent. The additional shrinkage between this pointgreater importance.

and the lower moisture content reached by somewoods will have little effect on their utility in

Seasoning Degradeservice.

Seasoning would be more rapid and the final A summary of the degrade occurring in theair-dry moisture content somewhat lower in the different woods as a result of seasoning under thedry climate prevailing along the south side of the test conditions is presented in table 3. All but 13island than in the San Juan area on the north of the woods seasoned satisfactorily, 17 with onlycoast, where these tests were conducted. The op- minor degrade, and 29 with a moderate but ac-posite conditions would occur in the humid moun- ceptable amount of degrade. For most purposes,tain regions of the interior where it is nearly im- the woods in class 1 and 2 are quite acceptable forpossible to season lumber without protection from

commercial use. But those in class 3 could prob-the heavy and frequent rainfall, which may reach

ably be improved by slower seasoning.200 inches annually at the higher elevations. It Most of the degrade occurred in the form of bowis probably impractical to air-dry lumber under and twist whereas cup and crook was of minorthese conditions. importance in most woods. With the exception of

In addition to climate, the method of piling and mamey, casuarina, and palo colorado, surfacethe amount of ventilation has considerable effect checks and end splitting during seasoning wereon the rapidity of air-seasoning. In this study not serious. The amount of end splitting wasthe woods were seasoned under conditions thatwere considered normal for the area.

undoubtedly reduced by the use of end coatings.However,

closer piling and less ventilation probably wouldhave retarded the rate of seasoning and, as a re-

However, the application of end-coating materialis recommended when seasoning hardwoods andis considered a common practice.

TABLE 3.— Rating of Puerto Rican woods for degrade occurring during air-seasoning of 1 1/8- to 1¼ -inchrough lumber 1

CLASS 1— MINOR DEGRADE

Species

CUP

Warp

Bow Twist Crook

Checks and splits

Surface End

See footnotes at end of table.

CUP

Warp

Bow Twist

CLASS 3— CONSIDERABLE DEGRADE

Crook Surface End

Checks and splits


TABLE 3 .— Rating of Puerto Rican woods for degrade occurring during air-seasoning of 1 1/8 - to 1¼ -inchrough lumber 4–Continued

CLASS 2— MODERATE DEGRADE

Species

1 Severity of defects are coded as follows:A–None D–ModerateB–Very slight E–SevereC–Slight F–Very severe

The frequency and severity of defects causingdegrade, particularly those causing surfacechecking, are often increased by overrapid drying.This can be prevented by closer piling, less venti-lation below, above, and around the piles, and byusing thinner stickers. Some warp may have been

2 Subsequent tests indicate that yagrumo hembra canbe air-dried with only moderate degrade under what mayhave been more favorable conditions.

caused by the “thick and thin” nature of the lum-ber, which complicated piling. However, thiscondition is not unusual in material sawed in smallsawmills, and it was accepted as a condition thatwill usually prevail whenever rough lumber isseasoned.


Tendency to WarpPROCEDURE

The inherent tendency of a wood to warp is animportant factor in the degrade that occurs duringseasoning and in stability and behavior of thewood after manufacture. Woods having an in-herent tendency to warp will generally incur more

more 4-foot, lengths of 1 1 /8 inch thick green lumber6 to 9 inches wide were end-racked and allowed toair-season to equilibrium with the surroundingatmosphere (fig. 3). This method permitted thetest samples to warp without restraint.

degrade during seasoning, and may warp in use.To determine this tendency for each wood, 10 or

F–495311FIGURE 3.— Four-foot boards end-racked for drying, a test of tendency to warp.

After becoming air-dry, the boards were placedon a flat surface and measured for bow, cup, andtwist. A long wedge (fig. 4), calibrated so that,each small division on the hypotenuse representeda vertical distance of 0.01 inch from the adjacentdivisions, was used in the measuring. The amountof warp was read in hundredths of an inch at theworst point, because the maximum defect in anypiece determines the amount of waste duringmanufacture. These readings were averaged forthe 10 or more samples for each species.

Results of the warp tests may be useful as aguide in pointing out the need for selecting season-ing techniques that, will overcome or at leastreduce the inherent tendencies of certain woodsto distort during air-drying.

RESULTSThe comparative ratings of the woods in the

warp test, (table 4) are in reasonably close agree-ment with results obtained in the air-seasoningstudy, although some differences are apparentbetween the two tests. Some woods showing atendency to undergo severe distortion in the. warptests seasoned with only moderate degrade duringair-seasoning. However, others showing uppoorly in the warp tests were also subject to mod-erate to heavy degrade when air-seasoned.

Two tentative conclusions can be drawn fromthese results: (1) warp tests reveal the inherenttendencies of the different woods to distort duringseasoning; and (2) the tendency of any wood to


FIGURE 4.— Calibrated wedge used to measure warp.F–495312

distort during seasoning is, to some extent, over-come by proper seasoning practices in the air-drying tests. It is well known that, piling boardsso that they are under restraint is effective in

reducing cup, twist, and bow. Similarly, pilinglumber in a way that will reduce the rapidity of.drying will also reduce surface tension and theaccompanying checking and distortion.

TABLE 4.— Twist, cup, and bow occurring in hardwoods when air-dried without restraint, arranged inorder from worst to best 1

Species Twist Cup Bow Species

1 Based on 1- by 7-inch by 4-foot boards, adjusted to 7-inch width where necessary.

Twist Cup BOW


Physical PropertiesSPECIFIC GRAVITY AND

MOISTURE CONTENTSpecific gravity is a fairly reliable indicator of

both the strength and machinability of wood. Ingeneral, heavy woods are stronger and machinebetter but with somewhat more difficulty thanlightweight woods. However, a number of ex-ceptions to this were found in tests of machiningproperties; some lightweight woods machinedbetter than others of greater density.

Specific gravity is used to express the relativeweight, of wood. Technically, specific gravity isthe ratio of the weight of a given volume of woodto that of an equal volume of water. Inasmuch asthe weight of a given volume of wood changeswith shrinkage or swelling caused by changes inthe moisture content, specific gravity is an indefi-nite value unless the conditions under which it isobtained are specified.

ProcedureSpecimens for determining specific gravity,

weight’ per cubic foot, moisture content, andshrinkage were cut. from the four sample boardsselected from each sample log as described previ-ously. Cross sections were cut from the centerand one or both ends of the sample boards aftertrimming had removed any part that may havelost moisture during conversion. The cross sec-tions were then planed to a uniform thickness of

5The point at which the cell walls are saturated withwater but no free water remains in the cell cavities.Generally this is at about 30 percent moisture content.

1.0 inch, and test. specimens were prepared with asmooth-cutting table saw. Most specimens meas-ured 1.0 inch along the radial plane, 2.5 inchesalong the tangential plane, and 4 inches on thelongitudinal plane. Specimens were selected tobe truly flat grained, but a nominal slope of thegrowth rings characteristic of good-quality flat-sawed boards was allowed.

Immediately after cutting, the specimens wereweighed to the nearest 1/10 gram and the threedimensions were determined to the nearest 1/ 1 0 0 0inch. A specially adapted dial micrometer wasused for these measurements (fig. 5). The speci-mens were weighed and measured again when air-dry and again finally after being placed in an ovenat 103° C. until ovendry. The data on specificgravity, shrinkage, and weight, per cubic foot(tables 5, 6, and 7) were computed from theweights and measurements of these specimens.

ResultsTable 5 shows the specific gravity for each

species, based on three different conditions: (1)green volume and ovendry weight; (2) air-dryvolume at 15 percent moisture content and ovendryweight; and (3) ovendry volume and ovendryweight. The gravity data based on ovendryvolumes and weights is termed “true” specificgravity, because it represents conditions that mayoccur simultaneously. The other two specificgravities are based on conditions that could notoccur simultaneously. These so-called “nomi-nal” specific gravities are useful in computing thetrue specific gravities at any moisture contentabove the fiber saturation point 5 and below the

F–495313FIGURE 5.— Dial micrometer adapted for measuring wood specimens to determine shrinkage and specific gravity,


fiber saturation point when the shrinkage rate isknown. The true-air-dry specific gravity for any

determined by the application of the factor incolumn 6 of table 5.

moisture content below 30 percent may also be

TABLE 5.— Specific gravity of green, air-dry, and ovendry wood

SpeciesMoisture

content ofgreen wood

(percent,)

Specific gravity based on ovendryweight and—

Green Air-dryvolume volume 1

Factor foradjusting

specificgravity 2

(1) (2) (3) (4) (5) (6)


TABLE 5.— Specific gravity of green, air-dry, and ovendry cooed-Continued

SpeciesMoisture

content ofgreen wood

(percent)

(1) (2)

Specific gravity based on ovendryweight and—

Greenvolume

(3)

Air-dryvolume 1

(4)

Ovendryvolume

(5)

Factor foradjustingspecific

gravity 2

(6)

1 Air-dry values are adjusted to 15 percent moisturecontent using factors listed in column 6.

2 Factor represents the change in true specific gravityfor each 1 percent change in moisture content between 0and 30 percent moisture content.

WEIGHT PER CUBIC FOOTThe weight of wood per cubic foot is useful in

determining the weight of finished articles or inestimating freight and handling costs. It is alsoa common denominator used to compare thedensity of one wood with that of another and itoften has more meaning to wood users than aspecific-gravity figure. However, the conditionof the wood, whether air-dry or green, or theactual moisture content for which the weight percubic foot is quoted must be specified. This isessential because the weight or specific gravity ofwood is influenced by the moisture content.Furthermore, when the moisture content is belowthe fiber saturation point, around 30 percent

3 Values are approximate because of occurrence ofsevere distortion during seasoning of test specimens.Values were computed from green to ovendry measure-ments and m-eights,content of 30 percent.

assuming an equilibrium moisture

moisture content, a further reduction in themoisture content is accompanied by shrinkage anda loss in volume.

The weights per cubic foot for air-dry wood at15 percent moisture content, and for green woodat the moisture content specified as shown in table6 are calculated from data in table 5. The weightper cubic foot can also be determined for anymoisture content from 0 to 30 percent moisturecontent by means of the factor in column 5 of table6. Weight per cubic foot for wood at anymoisture content above 30 percent can be deter-mined by multiplying the specific gravity incolumn 5 of table 5 by 62.4 and then multiplyingthis value by 1 plus the moisture content of thewood expressed as a decimal.

TABLE 6.— Weight of green and air-dry wood

Species

(1)

Green wood (at moisturecontent listed)

Air-dry wood (15 percentmoisture content)

Moisturecontent

(2)

Weight percubic foot

Weight percubic foot

(3) (4)

Factor foradjusting

weight percubic foot 1

(5)

PUERTO RICAN WOODS

TABLE 6.— Weight of green and air-dry wood-Continued

15

Species

(1)

Green wood (at moisture Air-dry wood (15 percentcontent listed) moisture content)

Moisture Weight per Weight percontent cubic foot cubic foot

(2) (3) (4)

Factor foradjusting

weight percubic foot 1

(5)

1 Factors for adjusting weight per cubic foot for each 1percent change in moisture content between 0 and 30 per-cent moisture content.

2 Approximate values.


SHRINKAGE indicator of the amount and severity of the warp

The average shrinkage values (table 7) for theand surface checking that develops during season-

Puerto. Rican woods involved are considerablying. The so-called nonrefractory woods, such as

below similar values for hardwoods of comparablemahogany, have nearly equal radial and tangen-

density from the United States. This accountstial values. Woods undergoing tangential shrink-

in part for the generally satisfactory manner inage not more than two times the radial shrinkage

which most of the Puerto Rican woods can bewill generally season without excessive warping

air-seasoned.or checking. But those with a ratio of 2½ or

The ratio of tangential to radial shrinkage is anmore will usually season rather unsatisfactorilyunless given more than average care.

TABLE 7.--Shrinkage values, in percent of original green measurements

SpeciesRadial Tangen-

tialLongi-tudinal

Green to air-dry 1 Green to ovendry

Volu-metric

Radial Tangen- Longi-tial tudinal

Volu-metric

PUERTO RICAN WOODS

TABLE 7.— Shrinkage values, in percent of original green measurements-continued

17

SpeciesRadial

Green to air-dry 1

Tangen-tial

Tangen-tial

1 At 15 percent moisture content. 3 Reliable data not available for shrinkage percent from2 Approximate values. green to air-dry.

Relatively few of the Puerto Rican woods ex-hibited excessive directional or volumetric shrink-age. However,aguacatillo,

those that did,algarrobo, casuarina,

includingeucalipto,

mamey, and yagrumo hembra also developed ex-cessive degrade during seasoning. Longitudinalshrinkage was relatively high in several woodshaving interlocked grain. This is a normal oc-currence for woods with this type of grain and

Longi-tudinal

Volu-metric

Radial

Green to ovendry

Longi-tudinal

Volu-metric

is not necessarily accompanied by excessive de-grade. Longitudinal shrinkage of more than 0.3percent is usually indicative of excessive warp.Palo Colorado, with a longitudinal shrinkage of0.62 percent, is a notable example. This wood,having tightly interlocked grain, developed verysevere warp along with equally severe surface andend checking.

Machining CharacteristicsPROCEDURE

The machining procedures were designed totest the different woods under a uniform and fairlytypical set of conditions prevailing in PuertoRico.” The woodworking machines and acces-sories used in the tests were typical of the smallhobby-shop size equipment found in most wood-working shops on the island. Except for theuse of forms and jigs to assure uniform handlingof the test specimens, the methods and techniquesof machining were typical of those used in work-ing Mexican mahogany in Puerto Rico.

The procedures were not selected as the mostsuitable for the different woods but rather to showwhat actually happens under the specified condi-tions. Thus the results show the comparative

6 Tests were patterned, with changes as required to meetlocal conditions, after procedures developed by E. M.Davis at the U.S. Forest Products Laboratory and pub-lished in Machining and Related Characteristics ofSouthern Hardwoods, U.S. Dept. Agr. Tech. Bul. 824,42 pp. 1942.

machining qualities of the woods under one set,of uniform conditions.

SELECTION OF TEST MATERIALNominal flat-grain, air-dry lumber free of knots

and seasoning defects was used in all machiningtests. Fifty boards of each species, 7 inches ormore wide, were selected at random, planed to2 5/32 inch thickness, and cut into machining speci-mens for the different tests (fig. 6). Test speci-mens were essentially heartwood, but piecescontaining sapwood were not discarded nor werespecimens rejected having some cross grain,irregular grain, or density lower or higher thanaverage.

GRADING

The smoothness of machined surfaces is themost important factor in judging the machinabil-ity of different woods. Accordingly, in this studythe test samples were examined for machining de-fects after each operation and were graded on a


numerical scale based on smoothness of cut. Agrade of 5 was considered excellent, 4 good, 3 fair,2 poor, 1 very poor, and 0 reject. Both the fre-quency and severity of defects were considered.Each wood was finally rated numerically 7 accord-ing to the weighted average grade of all specimensin each test. The percent of specimens gradinggood to excellent or fair to excellent is also shownfor most tests. This figure, which combines twoor more grades and is expressed in percent, is notnecessarily comparable to the numerical ratingbased on the weighted sum of the assigned grades

The woods were also separated into five broadgroups under each machining test, based on thecalculated ratings and the experience of the opera-tors making the tests. Separating the woods intoexcellent, good, fair, poor, and very poor groupsunder the respective machining tests necessitatedplacing certain woods in the top of one groupthough they were only very slightly inferior tothose in the bottom of the next higher group. Thiscondition and the necessity for introducing per-sonal opinion in making the separation intogroups should be considered by the reader whencomparing the relative machinability of the dif-ferent woods.

PLANINGPlaning is one of the most important opera-

tions in most woodworking plants in Puerto Rico.Woods that plane poorly are difficult to use wheresmooth surfaces are required. Consequently theplaning characteristics of the different woods isof primary importance in determining their utilityfor specific uses, especially in furniture manufac-ture. The tests were designed to measure andcompare the planing qualities of the differentwoods under uniform and fairly typical localconditions.

Procedure

The machine used in the tests was a 4- by 12-inchsingle-surface cabinet planer designed for finework in small woodworking shops. More than 90percent of all planers used on the island are ofthis type. The cutter head, holding three 12-inchknives, revolved at 4,500 r.p.m., making 60 cutsper inch. All tests were made with a knife angleof 29° and at a feed rate of 17½ feet per minute.The 29° cutting angle is somewhat greater thanthe 20° to 25° generally recommended for hard-woods, but it is typical for the type of machinesused in Puerto Rico. The knives were kept sharpat all times by frequent light sharpening and

7 Calculated by totaling the numerical grades of all sam-ples and multiplying this sum by 0.4 when 50 samples wereused, 0.2 for 100 samples, and 0.1333 for 150 samples.

Test specimens were essentially clear, flat-grainmaterial, 4 inches wide, 3 feet long, and 25/32inch thick. All material was air-dry. The testsinvolved planing 50 specimens of each wood at 1/ 3 2 ,

1 /16, and 1/8 inch depth of cut, totaling 150 differenttests for each species. Grading was based on thefrequency and severity of defects occurring dur-ing the planing; namely, chipped rain, raisedgrain, fuzzy grain, and chip marks fig. 7). Thenumber and severity of chip marks was fairlyconstant at each depth of cut for the differentwoods, so this test was eliminated from the finalanalysis. The final grade of each specimen wasbased on the lowest rating for any type of defectpresent, because defect determines the amount ofsanding required to make the piece acceptable forcommercial use.

occasional grinding and jointing in a machinespecially designed for that purpose.

Results

formly straight grain generally plant better thanthose with irregular grain, although certain woodswith heavily interlocked grain, such as palo colo-rado, planed very well. Chip marks were few inall woods at 1/32 inch depth of cut, moderate at 1/16inch, and frequent to severe at 1/8 inch. However,an efficient exhaust system would have eliminatednearly all of this defect.

Specific gravity and texture appear to have littleeffect on planing qualities. Woods having uni-

Nearly two-thirds of all the woods rated good toexcellent in planing This was based on a weightedaverage of all specimens planed to three depths ofcut (table 8). Of the 60 woods tested, only 6 wereconsidered poor to very poor in planing properties.and 16 rated fair. Slightly more than one-halfof the woods planed better than Hondurasmahogany.

The proportion of pieces rating good to excel-lent at different depths of cut varied according tospecies, but, in general, better surfaces were ob-tained at 1/8- and 1/16-inch cuts than at 1/32 inch.Table 9 shows that the heaviest cut, 1/8 inch, fre-quently gave the best results.

This is contrary to the results obtained withlarger cabinet planers. The difference is due tothe vibrations that occur when very thin cuts aremade in a small single-surface planer of the typeused in these tests. Inasmuch as the test was de-signed to compare and rate the different woodsunder uniform and fairly typical conditions, mostof those exhibiting fair to very poor planingqualities might be improved if better equipmentand techniques were used.


F IGURE 6.— Forright, afterboring.

each species, a set of sample pieces was prepared for the machining tests. Left, Before machining ;machining. A, Planing and screw splitting; B, turning: C, sanding; and D, shaping, mortising, and

F–495314–315


TABLE 8.— Planing: comparative rating of all species, based on averages for three depths of cut 1

Rating 2Species Rating 2

GOOD

Species Species

EXCELLENT GOOD— Continued FAIR-Continued

POOR

FAIRVERY POOR

Rating

1 1/8, 1/16, and 1/32 inch depth of cut.2 Calculated by totaling the numerical grades of the 150 samples of each wood and multiplying this sum by the

factor 0.1333 (100 divided by the possible total if all pieces were blemish-free. 150×5=750).

TABLE 9.— Planning: percentage of samples rated good to excellent at different depths of cut 1

SpeciesDepth of cut, Depth of cut

1/32 inchSpecies

1/8 inch1/16 inch1/8 inch 1/16 inch 1/32 inch

1 Considering all defects except chip marks.


M–24571–569–F

FIGURE 7.— Planning defects; A, Torn grain; B, chip marks; C, raised grain : D, fuzzy grain.


SHAPING Test specimens of each species consisted of 50pieces of typical flat-grain material, 4 by 18 inchesin dimension and 25/32 inch thick. Specimens werefirst handsawed to a curved outline on one sideand one end and then fastened to jigs and handfedin two operations past the cutters. One operationinvolved shaping along the end at right angle tothe grain and the other followed the curved out-line previously cut on each sample (fig. 8).

After shaping, the samples were graded on thebasis of four types of defects : torn grain, chippedgrain, raised grain, and fuzziness. For all prac-tical purposes, the most defective place on a shap-ing determines its grade, as the defect, at thatpoint controls the amount of sanding requiredto make the piece acceptable for commercial use(fig. 9).

Shaping is a common operation in woodwork-ing plants, particularly those that manufacturefurniture and related items. The operation gen-erally involves cutting a pattern on the edge of ex-posed surfaces such as tabletops and shelving.Its primary function is to add to the attractivenessof the finished products. Consequently, thesmoothness and detail of the shaping is of primaryimportance and was used as a basis for gradingthe tests specimens.

ProcedureThe machine selected for the tests was a single-

spindle type, operated at 11,000 r.p.m. by a belt-driven 1½ -horsepower electric motor, and fed byhand. Small machines of this type are used inmost furniture plants in Puerto Rico. A 2½ -inchcutter head holding three steel knives was usedthroughout the tests. ‘The knives were of a com-mon commercial pattern, cutting an outline vary-ing from right angles to parallel to the grain.Knives were sharpened at. frequent intervals andwere replaced when any appreciable wear wasevident.

ResultsMore than two-thirds of the woods rated good

to excellent in shaping, and only 10 were considered poor or very poor. The most unsatisfac-tory woods were in all cases light to extremelylight, in weight, whereas the medium to very heavywoods generally gave the best results.

FIGURE 8.— Finished shaping held in the jig used in the tent.F–495316


TABLE 10.— Shaping: comparative rating of all species based on smoothness of cut when consideringall side and end defects

Species Rating Species

EXCELLENT GOOD— Continued

GOODFAIR

Good toexcellentshaping

POOR

VERY POOR

Shaping characteristics were not always relatedto specific gravity, for some of the heaviest woods,such as higüerillo and casuarina, rated well downthe list. On the other hand, ausubo, a very heavywood, produced the best shapings of all, whileHonduras mahogany was ninth in the list of 60woods studied (table 10).

Inasmuch as this test compared the shapingqualities of the different woods under typical andreasonably uniform conditions, those exhibitingfair to poor shaping qualities might have beenimproved if special machining techniques wereemployed to overcome their specific problems.

T U R N I N G

Wood turning in Puerto Rico is generallylimited to bed posts and a few similar items inthe manufacturing of furniture. Imported Hon-duras mahogany is customarily used. Of thelocal woods, tabonuco is usually selected for this

RatingGood toexcellentshaping

work, although numerous other species have equalor superior turning qualities. Most shops usesmall, handfed, hobby-shop size machines, but afew semiautomatic machines are coming into use.

ProcedureThe tests were made with a small hand lathe

embodying the back-lathe principle with certainmodifications. The knife was a special milled-to-pattern type suitable for turning small pieces withconsiderable detail. It was held in a compoundrest of the type used for metal turning. Testmaterial consisted of 50 pieces of each wood, 25/32inch square and 5 inches long. The test involvedmost of the common cuts in turning, includingturning a bead, cove, and fillet, plus cuts at severaldifferent angles to the grain on each test specimen.All turning was done at 3,300 r.p.m.

Turnings were graded on the basis of smooth-ness of cut and sharpness of detail, with the poor-est point determining the grade for the specimen.


F–495317FIGURE 9.— Test samples showing different degrees of de-

fect when shaped at right angles to the grain.

The governing factor was the amount of sandingrequired to bring each specimen to an acceptablestandard. Grading was done on a basis of 0 to 5(fig. 10), as described on page 17.

ResultsThree-quarters of the woods rated fair to ex-

cellent when turned under what is consideredsevere turning conditions (table 11). In generalthe heavier woods turned better than those of lowdensity.

M–109037FIGURE 10.— Defects and different degrees of defects that

develop during turning.

All of the woods that rated very poor are verylight in weight. However, only part of the woodsrated excellent are extremely heavy. For example.moca is moderately heavy, yet it is an excellentwood to turn. Twelve species turned better thancaoba hondureña, which is well liked in the turn-ing trade. Tabonuco, the favorite turning woodin Puerto Rico. and cedro hembra, another well-regarded wood for turning, rated only fair on thebasis of these tests. Surprisingly, ausubo, one ofthe heavier woods, turned poorly under the testconditions. Inasmuch as the tests were conductedto determine the comparative turning qualities ofthe woods, it is evident most of them might givebetter results with more careful handling.

BORING

Boring is a common operation in woodworkingplants that make furniture and other wood prod-ucts in which dowels, rungs, spindles, or screwsare used in the assembly process. Machines usedin boring vary in size from small single-spindledrill presses to modern multiple-spindle boringmachines capable of boring a dozen or more holessimultaneously. Many different types of wooddrills and bits are available for the varied andoften highly specialized boring operations. Al-though boring work is generally concealed in thefinished product, the smoothness of cut and ac-curacy of hole size are of primary importancewhen dowels or rungs are used. A clean, smoothcut with a minimum tearing of the grain providesa tight fit and good glue-holding surfaces. Ac-curately sized holes are also important for ob-taining a tight fit and a strong, thin glue bond be-tween the hole surfaces and the dowel or rung.

Procedure

A simple-spindle, motor-driven boring machineoperating at 1,725 r.p.m. was used in the tests.The bit was a 1-inch, spear point, single twist,solid center type. It was maintained in good cut-ting condition by frequent sharpening, and it wasreplaced at the first sign of wear or damage. Testspecimens were held securely during boring in aspecial jig, and the bit was fed into the wood at auniform rate by a hand-feed mechanism (fig. 11).Mechanical means of feeding the bit into the woodwould have been desirable but were not availble.

Two holes were bored in each 50 test specimensof each species, 25/32 inch thick. The 100 holes foreach wood were then graded for smoothness ofcut, and they were rated according to the numeri-cal system described on page 17 (fig. 12).

The accuracy of hole size was measured forseveral species and was found to be at least asuniform as the size of the bits and doweling avail-able on the local market. Because of the dif-ficulty of making accurate measurements of holesize, this part of the test was abandoned.


TABLE 11.— Training: comparative rating of all species, based on smoothness of cut

(Based on percent of turnings graded fair to excellent)

Species Rating

EXCELLENT

GOOD

Species Rating Species Rating

GOOD— Continued FAIR-Continued

POOR

FAIRVERY POOR

ResultsThe majority of these woods bored satisfac-

torily. Only 4 of the 60 woods exhibited verypoor qualities in this respect, and 11 rated poor.Specific gravity appeared to be an importantfactor, with the heavier woods producing con-siderably better holes than light to medium densitywoods. All woods rated very poor and most ofthose rated poor were among the lightest used inthe tests.

The test was designed to treat all woods alikein order to develop comparative ratings for thedifferent species. Consequently, most. of thewoods exhibiting unsatisfactory boring qualitiescould be handled more satisfactorily under dif-ferent and less severe conditions. Even woods likeguano and panapén, although very difficult tobore, can be bored satisfactorily if special tech-niques and the proper bits are used.

A limited number of measurements of hole sizeindicated that hole size was most, accurate in thewoods rated good and poorest in those producingrough, torn holes. Holes were generally under-size in the dense, good-boring woods— actuallysmaller than the bit. Holes were considerablyoversize in the woods with rough, torn borings.Charring is a difficulty frequently encountered inboring very dense wood, but this can be eliminatedby increasing the rate of feed.

MORTISING

Mortise-and-tenon joints have been used forcenturies in fabricating all types of wooden struc-tures, furniture, and other objects. The mortise,usually a rectangular hole made to receive thetenon of another member, was for many years cutby hand. When nails, screws, and other fasteningdevices became plentiful and cheap, this type ofjoinery was no longer necessary. Such joints arestill used, but now most mortises are cut by ma-chines, principally in furniture and millwork

FIGURE 11.— Blank held in jig ready for boring test.


EXCELLENT

FIGURE 12.— Boring test samples, showing the variationF–495319

in smoothness of cut.

plants. Since tenoning is done in operations sim-ilar to shaping and planing, separate tests oftenoning were not made in this study.

The mortising tests were made with a hollow-chisel mortising tool operating in a conventionaldrill press. This type of mortising tool consistsof a specially designed bit revolving within a hol-low square chisel. It cuts a square hole. As thetool is pressed into the wood, the bit bores a roundhole, and the hollow chisel, following close behindthe bit, cuts out the corners.

GOOD

ProcedureFifty specimens of each wood, 25/32 inch thick.

were used for the test. One mortise was cut ineach test sample with a standard ½ -inch mortisingtool, the bit revolving at 1,250 r.p.m. Test speci-mens were held snugly in place during mortisingby means of a special jig. Because the machineused was of the hand-fed type, considerable carewas taken to maintain a uniform rate of feed forall species. Both the bit and chisel weresharpened at frequent intervals and replacedwhenever any wear or damage was evident.

The finished mortises (figs. 13 and 14) weregraded for smoothness of cut, in accordance withthe numerical grading system described on page 17.An attempt to measure the accuracy of mortisesize with a steel gage was impractical, because thevariation in size of mortising tools and the inac-curacy of measurements appeared to be greaterthan the variation in mortise dimensions of dif-ferent woods.

FAIR

Results POOR

Most of the Puerto Rican woods mortisedsatisfactorily. Ten of them mortised better thancaoba hondureña and all but 15 gave good to ex-cellent’ results. Specific gravity appears to be animportant, factor, with the heavier woods generallyproducing better mortises than the light-weightsoftwoods. In general, cuts parallel to the grainmere acceptably smooth in most woods. How-ever, cuts across the grain varied widely, someof them showing considerable crushing and tear-ing. The comparative rating of the woods aslisted in table 13 is based largely on smoothnessof cut across the grain.

TABLE 12.— Boring: comparative rating of allspecies based on smoothness of cut

Species RatingGood toexcellent,

holes

VERY POOR


F–495320 F–495321

FIGURE 13.— Test samples held in jig for mortising test FIGURE 14.— Test samples cross-sectioned to show differentwith hollow mortising chisel. degrees of tearing that occurred in mortising.

TABLE 13.— Mortising: comparative rating of all species, based on smoothness of cut

Species RatingGood toexcellentmortises

Species Rating

EXCELLENT GOOD— Continued

GOOD

FAIR

POOR

VERY POOR

Good toexcellentmortises


SANDINGSanding is an important operation in preparing

many products for paint, varnish, or other fin-ishes; it removes planing defects such as chipmarks, torn or raised grain, knife marks, fuzz, andsmall scratches or dents. Some coarse or open-grain woods also require considerable sanding toprovide a smooth surface for finishing. Thehigher grade products, such as furniture andcabinetwork, are carefully sanded before finishing.Blemishes that are not removed in the sanding areoften magnified when clear or partially opaquefinishes are applied. Consequently, woods selectedfor high-quality products must possess reasonablygood sanding characteristics.

Procedure

The tests were made with a small power-drivenbelt sander using 6-inch-wide endless sanding beltsapproximately 14 feet long. Fifty 2- by 10-inchtest specimens of each wood were sanded with 1/0grit, 50 with 2/0 grit, and 50 with 3/0 grit. Gar-net abrasives were used in all tests. The abrasivepaper was replaced frequently to avoid the effectsof wear, which reduces the size of the grit. Sand-ing was done parallel to the grain in a special jigholding eight test specimens at one time. Pres-

sure of the sanding belt against the test specimenswas applied by hand as uniformly as possible.Duration of the sanding varied according to thesize of the grit; the finest grit required the mosttime. A watch was used to keep sanding timeconstant for each size of abrasive paper. Aftersanding, the samples were inspected visually forboth fuzz and scratches, and they were graded ondegree of freedom from these defects.

Results

The woods exhibited generally satisfactorysanding properties, with caoba hondureña at thetop of the list and teca at the bottom (table 14).Thirty-eight of the 60 woods tested rated good toexcellent, and only 11 were in the poor to verypoor class. Specific gravity did not appear to bea dominant factor in sanding properties, althoughlightweight, open-textured woods tended to fuzzup more than others. Scratches were more readilyvisible on the surface of dense, fine-texturedwoods, just as fine scratches stand out on a mirroror polished metal surface. In general, fine-grained wood required a finer abrasive thancoarse-grained wood. The tests indicated that 3/0grit abrasive is normally required to reducescratching and fuzzing to an acceptable minimumfor high-quality finishes.

TABLE 14.— Sanding: comparative rating of all species, based on percentage of scratch- andfuzz - f ree p ieces 1

Species

EXCELLENT

Rating

GOOD— Continued

Species

GOOD

VERY POOR

FAIR

Rating

FAIR— Continued

POOR

Species Rating

1 Weighted average for 1/0, 2/0, and 3/0 grit sanding belts

PUERTO RICAN WOODS

Related PropertiesSCREW SPLITTING

In Puerto Rico, screws are usually driven withhandtools. Consequently, handtools were adoptedfor these tests of Puerto Rican woods. Screwshave the greatest holding power when drivensnugly into prebored lead holes that are equal tothe core diameter of the screw at a point halfway down from the top of the threads. Nor-mally screws are located as far from wood edgesas possible. However, since the object here wasto evaluate screw-splitting tendencies of the dif-ferent species, considerably more severe test condi-t ions were employed.

with a hand-operated drill press to insure straight-ness. Four screws were driven through the leadholes in each board into a softwood backing, usinga hand brace and screwdriver bit. Screws weredriven to a uniform depth, the base of the headbeing flush with the top of the board (fig. 15).

After the screws were driven, the boards wereinspected for complete splits at the points wherethe screws were sunk. A complete split was con-sidered to be one that extended through the endof the board and back beyond the screw. It alsohad to be visible on both sides of the board. Thewoods were then rated according to their com-parative resistance to splitting under the test, con-ditions (table 15).

ProcedureResults

Test material consisted of 25 boards 3/8 inchthick, 4 inches wide, and 3 feet long. Four leadholes, 1/16 inch in diameter, were bored in a line½ inch from one end of each board and approxi-mately ¾ inch apart and from each edge. Theywere about one-half the proper size for the No. 8screws used in the tests. The lead holes were bored

The tests indicated that woods having uni-formly straight, grain are more susceptible to split-ting than those having cross (interlocked) grain.Lightweight woods also were less susceptible tosplitting than heavy, dense woods. All PuertoRican woods rated excellent in resistance to screwsplitting were either light in weight or possessed

29

FIGURE 15.— Test samples illustrating screw splitting. Left, 0; center, 2 : right, 3.5 9 6 0 3 3 O — 6 1 — 3


TABLE 15.— Screw splitting: comparative rating of all species, based on percentage of split-free pieces 1

Species Rating

EXCELLENT GOOD— Continued FAIR

GOOD

Species Rating Species Rating

POOR

VERY POOR

1 Cedro hembra not included for lack of suitable material.

interlocked grain. Conversely, most of the woodsrated low mere dense and characterized by straightgrain.

Because these tests were designed to producecomparative results, the lead holes were purposelymade too small and screws were driven closeenough to the ends and edges of boards to obtaina sufficient, amount of splitting for comparativepurposes. Using larger lead holes and spacingscrews farther from the ends of boards wouldreduce spliltting in most of these woods, but thiswould not change their inherent susceptibility tosplitting.

RESISTANCE TO DRY-WOODTERMITES

The West Indian dry-wood termite, or “polilla,”Cryptotermes brevis Walker, is possibly the mostdestructive wood-boring insect in Puerto Rico.With few exceptions, it can destroy any native orimported woods. The winged adults move aboutwith ease, infesting wood wherever they find it–the woodwork or framing in a house, the pictureframes on the wall, or the oxcart in the field. Thefrequency and extent of damage by this termiteoften is sporadic and unpredictable. Woods ratedvery susceptible to attack often give long and satis-factory service. Yet at other times the same woodsare attacked and almost completely destroyedwithin a few years, or sometimes in a few months.Despite this inconsistency, the wood user should

recognize the relative susceptibilities of the dif-ferent woods to damage and ultimate destructionby this voracious enemy. He can then either usewoods having natural resistance to termites inespecially vulnerable locations or protect the sus-ceptible woods with chemicals prior to use.

Procedure

Tests to determine the resistance of the differentwoods to damage by the dry-wood termite wereconducted by Dr. G.N. Wolcott of the Universityof Puerto Rico Agricultural Experiment Station,using small test specimens prepared as part of thisstudy. Only heartwood was used in the tests, be-cause sapwood is always less resistant and in mostcases very susceptible to termite attack. The speci-mens were placed in petri dishes with a small num-ber of termites at room temperature and withoutlight. Relative resistance was established by pro-gressive removal of the blocks attacked. The basicnumerical ratings were West Indies mahogany, 80:capá prieto, 60; and laurel sabino, 40.

Results

Only 2 of the 60 species tested were rated veryresistant to attack by the dry-wood termites: oneof these, teca, is an exotic tree grown only in plan-tations in Puerto Rico (table 16). Six specieswere rated resistant, 13 moderately resistant, andthe remaining 39 very susceptible. On this basis.


TABLE 16.— Natural resistance of woods to attack by the West Indian dry-wood termite 1

Species Rating

VERY RESISTANT

Species

MODERATELY RE-SISTANT— Continued

Species

VERY SUSCEPIBLE—Continued

RESISTANT

VERY SUSCEPTIBLE

MODERATELYRESISTANT

Rating Rating

1 Tests conducted and ratings established by Dr. G. N. Wolcott, University of Puerto Rico Agricultural Experi-ment Station.

about two-thirds of the native species reachingsaw-log size are used at considerable risk of ter-mite attack. Nevertheless, this is not so serious asit first seems; woods like African mahogany, Phil-ippine mahogany, and baboen— rated 30, 33, and31 respectively in natural resistance to termites—are used extensively on the island without seriouslosses.8 Similarly, furniture made of maple andbirch from the United States has given excellent

service although rated very susceptible to termiteattack.

In many instances, furniture made of susceptiblewoods becomes obsolete or worn out before beingseriously damaged by termites. Even the mostsusceptible woods can be made more or less im-mune to termite attack if impregnated with one ofthe numerous chemicals recommended for thispurpose.

Summary and ConclusionsAll woods possess a number of properties that

affect their utility for different purposes, and thisshould be considered in selecting material for anyspecific purpose or product. Other propertiesthat are of only occasional significance are usuallyignored except in circumstances when they havean effect on the usefulness of the wood. This studyhas been limited to certain properties that are ofprimary importance in the wood-using industry.The summation of these properties provides afairly reliable estimate of the general utility ofeach wood and its suitability for specific purposes.The tests also show how each wood compares indifferent qualities with other woods, its good qual-ities, and the difficulties that may be encounteredin its utilization for certain purposes.

8 Wolcott, George N. An index of the termite-resistanceof woods. Univ. Puerto Rico Agr. Sta. Bul. 85, 26 pp. 1950.

The different tests covered in this study aresummarized in tables 17 and 18. The reader canobtain a general idea of the characteristics of each-wood by reading across the tables and can comparethe individual properties of the different woods byfollowing the respective columns from top tobottom.

It is apparent, that in general utility the PuertoRican woods are equal or possibly superior to acomparable number of hardwood timbers from theUnited States or Europe. In general, the PuertoRican woods air-season more satisfactorily thanwoods from the temperate zone, have equal or per-haps more favorable shrinkage properties, andmachine somewhat, more satisfactorily. This isclearly evident in the tables on machining charac-teristics, in which Honduras mahogany (caobahondureña)— a wood highly regarded in this re-spect-was rated considerably below a number ofPuerto Rican woods in most machining properties.


TABLE 17.— Summary of physical properties

SpeciesSpecificgravity 1

Shrinkage from green toovendry

Green Air-dry RadialTan-

gentialVolu-metric

Percent Pounds Pounds Percent Percent Percent

Weight per cubicfoot

Air-seasoningcharacteristics

Rates 3

degrade 4

Amountof

Resist-ance todry-wood

ter-mites 5

See footnotes at end of table.

33PUERTO RICAN WOODS

T A B L E 1 7 . — Summary of physical properties— Continued

Weight, per cubicfoot

Shrinkage from green toovendry

Air-seasoningcharacteristics Resist-

ance todry-wood

ter-mites 5

SpeciesSpecific

gravityTan-

gentialVolu-metric

mountof

degrade 4

AGreen Air-dry 2 Radial Rates 3

1 Based on green volume and ovendry weight.2 At 15 percent moisture content.3 Rate of drying for 11/8-inch lumber properly piled

under corer.R— Rapid (11-17 weeks)M— Moderate (18-26 weeks)S— Slow (27 weeks or more)

4 Based on frequence and amount of cup, twist, bow,crook, and end and surface checking occurring from greento air-dry.

1— Minor degrade2— Moderate degrade3— Considerable degrade

5 VR— very resistant; R-resistant; MR— moderatelyresistant; VS— very susceptible.

6 Approximate values.

TABLE 18.— Summary of machining characteristics

Resistanceto screwsplitting

Species Planing Shaping T u r n i n g Boring Mortising Sanding

34

TABLE 18.— Summary of machining characteristics — Cont inued

Species

U.S. DEPT. OF AGRICULTURE HANDBOOK NO. 205

Planing Shaping Turning Boring Mortising SandingResistanceto screwsplitting

A considerable number of the Puerto Ricanwoods possess unusual attractiveness, fitting themfor a variety of uses where this property is impor-tant. This quality plus a wide range in density,hardness, and strength, among the woods tested—from guano (balsa) at the lower level to ucar andansubo at the top-provides the consumer with anextensive choice of woods for any specific purpose.

In general, one or more and frequently several ofthese woods are suitable for most of the commonwood uses on the island. Their utilization to thefullest extent possible in preference to importedmaterial would encourage better management ofthe forests and, at the same time, would materiallybenefit the local economy.

PART 2. TIMBER DESCRIPTIONSACHIOTILLO

Alchornea latifolia Sw. (spurge family, Euphorbiaceae)

Achiotillo (fig. 16) is a pale creamy-brown colorthroughout, except for frequent reddish-brown“resin ductlike” canals, which are alined in a radialdirection. On flatsawed surfaces, these blemishesrange in size from minute round specks to fairlylarge ones and may be either filled with a opaquebrown substance, partly occluded, or open. Thewood has medium texture, straight to slightlywavy grain, low luster, and lacks characteristicodor or taste when seasoned. Growth rings arenot evident. The wood is fairly soft and mod-erately light, yet firm and strong for its weight of29 pounds per cubic foot when air-dry and 51pounds when green.

The wood is moderately strong for its densityand has unusually good bending qualities whendry. Recent tests indicate it is very acceptablefor kite sticks and other small bent parts. Itmay also be well suited for match splints, veneerflatware, and other similar uses. Achiotillo lacksthe strength and durability for most outdoor con-struction but with preservative treatment wouldbe useful for light carpentry and some types ofexterior construction. It is also suitable forboxes, crates, toys, and temporary cement forms,and it has been recommended for utility veneer inBritish Guiana.

Achiotillo air-dries at a moderate rate. Greenlumber 11/8 inch thick dries to about 17 percentmoisture content in 5 months under cover in theSan Juan area. Moderate degrade occurs duringseasoning, mostly in the form of cup, bow, andtwist, and a very small amount of surface check-ing. Sliced veneer stock is also reported to drysatisfactorily with a minimum of checking andsplitting. Seasoning is accompanied by moderateand fairly uniform shrinkage. Flatsawed boardsshrink at the rate of 1/10 inch (0.9 percent) per foot,across the growth rings and 1/3 inch (2.4 percent)per foot parallel to the growth rings from green toair-dry.

The wood saws and works very easily in all ma-chining operations. Good surfaces are obtainedin planing, but in most other machining operations.because of the wood’s moderate density and soft-ness, it is badly torn and crushed and tends towardfuzziness. Special care is necessary in machin-ing to keep such defects to an acceptable minimum.Screws and nails can be driven easily into the woodwith a minimum of splitting.

Achiotillo is very susceptible to damage by thedry-wood termite and other insects, and it isquickly destroyed by decay when in contactwith the ground. Logs are soon damaged by pin-hole borers and discolored by sap-staining fungiif the tree is not processed immediately after fell-ing. Green lumber is also subject to blue stainunless the surface is allowed to dry quickly afterSawing or is treated with an antistain solution.

F--495323

FIGURE 16.— Achiotillo: Top, flatsawed; bottom,quartersawed.

35

36 U.S. DEPT. OF AGRICULTURE. HANDBOOK NO. 205

AGUACATILLOMeliosma herbertii Rolfe (sabia family, Sabiaceae)

Aguacatillo (fig. 17) has pale-brown heartwood,often with an attractive orange overcast, whichis not readily separated from the lighter coloredsapwood. Growth rings are faintly marked byzones of darker colored tissue that appear on theradial surface as tine scratches or lines, giving thewood a rather attractive appearance resemblingcedro hembra. The wood has medium luster,moderately coarse texture, and straight to fre-quently interlocked grain. Seasoned wood has nodistinctive odor and taste. Aguacatillo is mod-erately heavy, firm, and tough, weighing 33

F— 495324

FIGURE 17.— Aguacatillo : Top, flatsawed ; bottom,quartersawed.

a good polish.

Despite the presence of silica in the wood rays,aguacatillo saws and machines easily, but withgenerally unsatisfactory results. It. gives goodresults in planing and can be sanded to a smooth,even surface. The results are poor in most othermachining operations because of the wood’s tend-ency to tear and crush in these operations. How-ever, because of its softness and frequently inter-locked grain, aguacatillo is rated excellent inresistance to screw splitting. It should also acceptand hold nails well, glue satisfactorily, and take

Aguacatillo is very susceptible to termites andother insects and poorly resistant to decay. Thewood’s low durability, poor seasoning properties,and difficulty in working hampers its utilization,

Seasoning is accompanied by relatively highand uneven shrinkage. Flatsawed lumber shrinksat the rate of 5/16 inch (2.5 percent) per foot acrossthe growth rings and 7/8 inch (7.5 percent) perfoot parallel to the growth rings in seasoning fromgreen to air-dry.

amount of bow, twist, crook, and surface check-ing. Sap-staining fungi are also active duringthe early stages of drying unless the wood isdipped in an antistain solution or is surface-driedimmediately after sawing.

The wood seasons at a moderate rate but de-velops considerable degrade in the process.Green 11/8 inch lumber requires 5 months to air-dry to about 17 percent moisture content undercover in the San Juan area. Seasoning is accom-panied by considerable degrade.ticularly troublesome,

Cupping is par-along with a moderate

pounds per cubic foot when air-dry and 49 poundswhen green.

and the infrequent occurrence of aguacatillo andthe relatively small size of the logs also reduceits importance as a commercial timber. How-ever, it is attractive and suitable for furniture,cabinetwork, paneling, interior trim, and otherdecorative purposes if the user is willing to con-tribute sufficient. time and care in machining andsanding operations. It can also be used for boxes,crates, general interior and exterior construction,and carpentry. In general? the wood should beused only where high durability or great strengthare not essential.

ALGARROBO (COURBARIL)Hymenaea courbaril L. (legume family, Leguminosae)

Algarrobo (fig. 18), also known as courbaril andWest, Indian locust, is one of the best known andmost. useful woods of the American tropics. Theheartwood is salmon red to orange brown in colorwhen freshly cut, changing to russet, often with

dark streaks, upon seasoning and exposure.Heartwood is distinct from sapwood. At times itmay have a golden luster. The white to gray sap-wood is abnormally thick, particularly in rapidlygrown second-growth trees. Interlocked grain is

37PUERTO RICAN WOODS

characteristic, but occasionally straight grain isseen. The wood is mostly medium textured andwithout distinctive odor or taste when seasoned.Growth layers are not readily evident.

The wood is particularly attractive on the radialSurface, resembling sugar maple (Acer saccha-rum) in this respect. Its radial surface is dis-tinguished by a lustrous sheen and scattered linesof vessels. This is a very heavy wood, weighing53 pounds per cubic foot when air-dry and 71pounds when green.

Algarrobo is difficult to season. In the tests,green lumber seasoned at a moderate rate, requir-ing approximately 6 months to air-season to about17 percent moisture content under cover in theSan Juan area. Considerable degrade occurredin the form of moderate cup, crook, and surfacechecking, moderate to severe bow and twist, slightend checking, and a moderate amount ofcasehardening.

Shrinkage during seasoning is moderate in alldirections, especially for a wood of algarrobo’sdensity. It compares very favorably in this re-spect with black locust (Robinia pseudoacacia) ofthe United States, which it noted for its lowshrinkage in relation to its high density. Greenalgarrobo lumber shrinks 2/10 inch (1.7 percent)per foot across the growth rings and about 4/10 inch(3.5 percent) per foot along the growth rings indrying to 15 percent moisture content. It is re-ported to absorb moisture rather quickly but isconsidered reasonably stable in use.

The wood is very strong, tough, and hard, andis superior in strength to white oak (Quercusalba) of the United States in both green andair-dry condition. It also compares favorablywith teak in most strength properties. Algarrobois moderately difficult to saw and machine becauseof its high density, but except in planing it canbe machined to a smooth surface. The wood issomewhat difficult to plane because of the tendencyto tear easily in pieces having roey grain. It isdifficult to nail but has good resistance to splittingby screws; it takes glue well and finishes satisfac-torily, but does not take a high polish. The woodsteam-bends very well, being comparable to whiteoak in this respect.

Algarrobo is reported to be unusually variablein decay resistance, ranging from nondurable tovery durable in contact with the ground. It isreadily damaged by marine borers but it is veryresistant to dry-wood termites, rating well abovethe West Indian and Honduras mahoganies andteca in this respect. The wood weathers badly,and heavy checking occurs when the wood is ex-posed without the protection of paint.

F— 495325

FIGURE 18.— Algarrobo: Top, flatsawed : bottom,quartersawed.

Algarrobo’s high shock resistance fits it admira-bly for use in sporting goods and tool handles inplace of white ash (Fraxinus americana). It isalso quite suitable for steam-bent boat parts orother similar items for which oak is generally used.It provides a highly wear-resistant surface forflooring and stair treads. Wood from the widelayer of sapwood in second-growth timber is con-sidered exceptionally good for natural and blond-finish furniture.

Both the sapwood and heartwood should beparticularly attractive as veneer and plywood aswell as for furniture, cabinet work, interior trim,and turnery. The wood is currently used in theAmerican tropics for ship planking, gear cogs,wooden-wheel parts, heavy and durable buildingconstruction, and loom harnesses. Because of itshigh resistance to abrasion, algarrobo is preferredfor sugar-mill and other mill-machinery parts,lock gates in nonteredo areas, shoe heels, and icesheathing.


ALMÁ CIGO (GUMBO-LIMBO)Bursera simaruba (L.) Sarg. (bursera family, Burseraceae)

This tree is called almácigo in Puerto Rico andgumbo-limbo in Florida. The logs are generallyshort and often crooked, but they are usually avail-able in medium to large diameters. Although sapstain develops in freshly cut logs soon after thetree is felled, it can be controlled if the logs aremilled immediately after felling and the lumberis dipped in an antistain solution before piling.Roth the heartwood and sapwood of almácigo area uniform cream to light-brown color throughout(fig. 19). However, because of sap-staining,almácigo is most often known as a wood of bluish-gray color. The wood has fine texture, straight tosometimes irregular grain, moderate luster, andpossesses no distinctive order or taste. Growthrings are either absent or indistinct.

Seasoned wood is soft and light yet firm, tough,and fairly strong for its weight. Almácigo’s bestmechanical property is its good resistance to split-ting. Air-dry wood weighs 22 pounds per cubicfoot and green wood about 47 pounds per cubicfoot at 17 percent moisture content.

F-495326

FIGURE 19.— Almácigo : Top, flatsawed ; bottom,quartersawed.

Almácigo air-seasons rapidly with minor de-grade in the form of very slight cup and bow andslight twist. Crook, surface checking, and end de-fects are not troublesome. Green lumber 11/8inches thick air-seasons to about 18 percent mois-ture content in slightly over 4 months under coverin the San Juan area. Exceptionally low shrink-age. occurs during seasoning. Flatsawed boardsshrink approximately 1/4 inch (2.1 percent) perfoot in with and 1/8 inch (2.1 percent) per foot inthickness during seasoning.

The wood works easily with either hand ormachine tools but-except in planing and sand-ing-the surfaces are severely torn and crushedin the machining operations. Although the woodis rated good in planing and, sanding, slight fuzzi-ness may occur in both operations. The use ofvery sharp, thin cutting edges and reduced feedrates are required to reduce tearing and crushingto a minimum. The wood has excellent resistanceto screw splitting, holds nails firmly without split-ting, and can be stained and finished satisfactorily.

The logs are reported to peel well on rotarylathes in Mexico without preliminary heating orbark removal, although some logs produce veneerwith a “woolly” surf ace. Yield of acceptable faceveneer averages 30 to 40 percent. The veneer hasnumerous pin knots, some mineral streaks, andoccasionally a “birds-eye” figure like that in sugarmaple.

Almácigo is very susceptible to termites andother insects, very perishable in the soil, and

Logs are subject to early and severe attack bypresumably has little resistance to marine borers.

pinhole borers in addition to the above mentionedsap-staining fungi. However, both heartwoodand sapwood are easily impregnated with pre-servatives, giving the wood good resistance todecay and insects.

Almácigo does not possess sufficient attractive-ness and strength for use in furniture, but it isrecommended for boxes, crates, cement forms,interior carpentry, and all types of light construc-tion. It has been used for match splints inJamaica. Despite almácigo’s relatively poormachining qualities, the wood’s low and uniformshrinkage indicates that it may be suitable forpatternmaking and other similar uses where alightweight, easily worked, and stable wood isrequired. In some areas the principal use of thetree is for posts and poles which take root anddevelop into living fence posts and telegraphpoles.

The wood is used for utility plywood in Mexicounder the name “Mexican white birch”: it is alsoconsidered a good material for core stock. Ingeneral, almácigo can be used as a substitute forpine or other lightweight conifers but, lacks thestrength of these woods.


ALMENDRATerminalia catappa L. (combretum family, Combretaceae)

Almendra, or Indian-almond, has becomenaturalized in Puerto Rico and elsewhere in tropi-cal America. The seasoned heartwood is amedium reddish brown, marked with slightlydarker colored stripes (fig. 20). The sapwood isindistinct and somewhat lighter in color. Thegrain is generally irregular and often interlocked;texture medium; luster rather high. A slightodor is often noticeable in seasoned wood. Long,narrow zones of tension wood occur often andcause considerable trouble in machining opera-tions. The wood is moderately heavy, weighing 44pounds per cubic foot when air-dry and 66 poundswhen green. It is moderately strong, hard, andtough.

The wood seasons rapidly, 11/8-inch green lum-ber reaching approximately 18 percent moisturecontent in slightly over 3 months under cover inthe San Juan area. A moderate amount of warp-ing occurs during seasoning, but surface and endchecking are almost absent under the usual dryingconditions.

Shrinkage is moderate and uniform during sea-soning, indicating that almendra should be stableafter manufacture. Green lumber shrinks at therate of 2/10 inch (1.8 percent) per foot across thegrowth rings and 3/10 inch (2.5 percent) per footalong the growth rings during seasoning to 15percent moisture content.

Almendra saws and machines rather easily, butwith generally unsatisfactory results. Torn andfuzzy grain is very common in planing, shaping,and turning, especially in pieces containing ten-sion wood or irregular grain. Rough and torngrain is also common in boring and mortising. Itsands to a fairly good surface and has good re-sistance to screw splitting. Careful machining isnecessary to keep machine defects to an accept-able minimum for most uses.

Almendra is very susceptible to dry-woodtermites. On the basis of tests on closely relatedspecies, it should be durable in contact with theground but probably is quite susceptible to attackby marine borers.

The wood is very attractive when finished andwould be useful for millwork, furniture, veneer,

F— 495327

FIGURE 20.— Almendra: Top, flatsawed;bottom, quartersawed.

and cabinetwork if carefully handled. If almen-dra possesses the durability of other species of thegenus, it should be acceptable for many uses inexterior construction that require a moderatelystrong hard, durable wood. It has been recom-mended in other Caribbean areas for framing.planking, and other parts of boats; general con-struction, bridge timbers, railway crossties, andflooring. It is also used to some extent for boxes,crates, and other shipping containers.

AUSUBO (BALATA)Manilkara bidentata (A. DC.) Chev. (sapodilla family, Sapotaceae)

Ausubo, also known as balata, is one of thestrongest and most attractive woods available forcommercial use in Puerto Rico. The whitish topale-brown sapwood (fig. 21) is distinct but noteasily separated from the heartwood. Greenheartwood is light red when cut, turning to a dark-reddish color when dry. The wood has a uni-formly fine texture without pronounced figure; the

grain is usually straight but may be coarsely inter-locked at times. A characteristic odor is some-times present in green wood but is not evident afterseasoning although dry wood does have a char-acteristic oily feel. Ausubo is exceptionally hardand heavy, weighing 64 pounds per cubic footwhen air-dry and 75 pounds when green.


F— 495328

FIGURE 21.— Ausubo : Top, flatsawed; bottom,quartersawed.

Despite its density, ausubo air-seasons at afairly rapid rate, reaching an air-dry moisturecontent of 19 percent in 4 months under cover inthe San Juan area. Seasoning degrade is limitedto a small amount of cup and bow and slight twist.Surface checking and end splitting were not, evi-dent’ in the tests.

ing to 15 percent moisture content.

Ausubo undergoes moderate shrinkage for awood of its density. Green wood is reduced ap-proximately 3/10 inch (2.5 percent) per foot ofwidth across the growth rings and 9/16 inch (4.5percent) per foot along the growth rings in season-

fig. 22) of caimitillo, or mesa,yellowish brown without pro-

luster, and is ordorless and tasteless. Air-drywood weighs about 52 pounds per cubic foot and

The heartwoodis a uniform lightnounced figure. Seasoned wood resembles that ofsugar maple and yellow birch (Betula alleghanien-sis) in appearance. The sapwood is lighter incolor and not clearly differentiated from the heart-wood. Growth rings are indistinct. The woodhas uniformly fine texture, straight grain, medium

green wood 66 pounds per cubic foot.Caimitillo air-seasons rapidly, reaching 17 per-

cent moisture content in 4 months under cover inthe San Juan area. Only minor degrade occursduring seasoning, in the form of slight bow. No

Ausubo is moderately hard to machine becauseof its high density but cuts cleanly in ripping andcrosscutting without appreciable dulling of thecutting edges. The wood gives good to excellentresults in most machining operations except turn-ing, which must be done slowly and carefully toavoid tearing and rough surfaces. It is also dif-ficult to nail and is susceptible to splitting byscrews. Ausubo is an excellent. wood to steam-bend, comparable to oak in this respect, but isdifficult to glue. It finishes beautifully and rathereasily, the finished wood resembling mahogany.

The wood is considered very resistant to decay,very susceptible to marine borers, moderately re-sistant to dry-wood termites, and very resistant tosubterranean termites. Pinhole borers will at-tack the sapwood of green logs if left in the woodsfor several weeks, and powderpost beetles maydamage the sapwood after seasoning. Sap-stain-ing fungi are not troublesome during seasoning.Ausubo does not weather well; it develops severechecks when exposed to the weather without theprotection of paint.

This wood is one of the strongest growing in theAmerican tropics, equaling greenheart (Ocotearodiaei) in most strength properties and exceedingwhite oak in all respects except resistance to split-ting. Ausubo’s excellent steam-bending proper-ties make it well fitted for boat frames and otherbent work. The wood’s fine texture, straight. grain,high density, and good finishing properties qualifyit for use in shuttles, loom harnesses, and othertextile items, billiard cues, violin bows, and furni-ture. Its great strength and high resistance towear recommends it, for use as ice sheathing, boatframes, mill rollers, keel shoes, and pulpmill equip-ment such as beater liners, bed plates, and al-ligator bars.

Ausubo is also used extensively for railway ties,utility poles, ax and tool handles, heavy construc-tion, flooring, and bridge work. It is used verysatisfactorily in many areas for all types of furni-ture cabinetwork because of its attractiveness,great strength, and good finishing qualities. Thewood is also highly recommended for flooring,bench tops, and stair treads in industrial plantsand machine shops.

CAIMITILLOMicropholis chrysophylloides Pierre (sapodilla family, Sapotaceae)


surface or end checking, casehardening, or otherdefects were apparent in the study.

Shrinkage is moderate and very uniform for awood of caimitillo’s high density. Green woodshrinks 5/16 inch (2.6 percent) per foot across thegrowth rings and slightly over 7/16 inch (3.6 per-cent ) per foot along the growth rings in seasoningto 15 percent moisture content.

Silica in the wood makes sawing and machin-ing moderately difficult and causes a rapid dullingof saw teeth and cutting edges. However, caimi-tillo machines to a glassy-smooth surface in mostoperations. It is rated good to excellent in allwoodworking operations except sanding. Thetypically straight-grained material showsscratches readily in sanding. Also, it splitseasily when screws or nails are driven unlessadequately sized lead holes are used. Caimitillofinishes smoothly and takes a high polish.

The wood is hard, strong, and tough, resemblingsugar maple and yellow birch in strength proper-ties. It is considered moderately resistant to dry-wood termites and decay and has little resistanceto marine borers, based on tests in Hawaiianwaters.

Caimitillo is an excellent wood for furniture,cabinet work, interior trim, flooring, paddles, agri-cultural implements, and tool handles. Its closeresemblance to sugar maple and yellow birchshould make it suitable for veneer and plywoodand for numerous other purposes for which thosespecies are commonly used. The wood is also wellsuited for all types of interior and exterior con-struction, and general carpentry, and for pilingin nonteredo areas.

F— 495329

FIGURE 22.— Caimitillo: Top, flatsawed ; bottom, quarter-sawed.

CAIMITILLO VERDEMicropholis garciniaefolia Pierre (sapodilla family, Sapotaceae)

Caimitillo verde (fig. 23) is very similar tocaimitillo in appearance and physical properties,the two woods being almost inseparable whenmixed. The heartwood is a uniform light yellow-ish brown and not. readily separated from thelighter colored sapwood. The wood is similarto that of sugar maple in general appearance buttends to be somewhat darker in color. It has uni-formly fine texture, straight grain, medium luster,and is odorless and tasteless. Growth rings arenot distinct. The wood is moderately heavy,weighing about 49 pounds per cubic foot whenair-dry and 61 pounds when green. In com-parison, sugar maple weighs 44 pounds whenair-dry.

Caimitillo verde air-seasons rapidly withmoderate degrade. Green lumber seasons toabout 18 percent moisture content in 3 monthsunder cover in the San Juan area. Degrade con-sists of a moderate amount of warping and almostno surface or end checking. Shrinkage is espe-cially low and uniform for a wood of caimitilloverde’s density. From green to air-dry, greenlumber shrinks at the rate of ¼ inch (2.1 percent)per foot across the growth rings and 3/8 inch (3.4percent) per foot parallel to the growth rings.

The wood is moderately difficult to saw andmachine, because of high density and the pres-ence of silica that rapidly dulls saw teeth andcutting edges. However, caimitillo verde ma-chines with good to excellent results in all opera-

42 U.S. DEPT. OF AGRICULTURE. HANDBOOK NO. 205

tions. It also has a good resistance to screwsplitting and should take nails equally well, gen-erally somewhat better than caimitillo (mesa)in this respect. The wood finishes very smoothlyand takes a high polish.

Caimitillo verde is hard, strong, and tough,resembling sugar maple in these properties. Itis considered very susceptible to dry-wood ter-mites, as compared with caimitillo (mesa) whichis rated moderately resistant. Its similarity tocaimitillo otherwise would indicate the wood ismoderately resistant to decay and very susceptibleto damage by marine borers.

This wood is suitable for most of the sameproducts that sugar maple and yellow birch areused for in the United States, particularly veneer,and plywood, furniture, cabinetmaking, turning,interior trim, flooring, agricultural implements,and tool handles. It should also give good serv-ice in all types of interior and exterior construc-tion, piling in nonteredo waters, and in generalcarpentry. Caimitillo verde is one of the highestquality woods growing on the island, and it shouldbe used for purposes that utilize its superiordecorative and strength properties.

F— 495330

FIGURE 23.— Caimitillo verde : Top, flatsawed ; bottom,quartersawed.

CAOBA HONDUREÑA (HONDURAS MAHOGANY)Swietenia macrophylla King (mahogany family, Meliaceae)

More caoba hondureña is used in furnituremanufacture in Puerto Rico than any other wood.It is obtained in the form of rough-air-dry lum-ber from Mexico. The tree is not native toPuerto Rico but has been planted extensively inthe Luquillo Mountains and to a lesser extentin other areas. Occasionally limited amountsof small-size plantation-grown logs are availablefor commercial use. The tree grows well whenplanted on the proper sites, but it is easily up-rooted during hurricanes and may never becomeavailable in large quantities. The tree and woodare called caoba hondureña, Mexican mahogany,and Honduras mahogany in Puerto Rico.

‘The heartwood (fig. 24) is pinkish to salmoncolored when freshly cut, later becoming lightreddish brown with a golden luster. The yellow-ish-white sapwood is generally 1 to 2 inches wideand clearly demarcated from the heartwood. Thegrain is commonly interlocked, producing a wide

attractive stripe figure on quartersawed surfaces.Occasionally a mottled, fiddleback, raindrop,roey, or curley figure is present. The texture ofthe wood is medium to rather fine and uniform.Growth layers are indistinct. Seasoned heart-wood is without characteristic odor or taste.

Much of the caoba hondureña used in PuertoRico contains tension wood composed of soft gela-tinous fibers that are conducive to excessive longi-tudinal shrinkage and increased internal stressesduring seasoning. This causes increased warpingduring seasoning and the development of fuzzi-ness during sawing and other machining opera-tions.

Plantation-brown wood averages about 31pounds per cubic foot when air-dry and 40 poundswhen green. Forest-grown wood is slightlyheavier, weighing about 44 pounds per cubic footgreen and 33 pounds air-dry.

Caoba hondureña seasons rapidly and with veryminor degrade unless tension wood is present.


The wood is world-renowned for its unusually lowand uniform shrinkage and good stability aftermanufacture. It is considered one of the fewnonrefractory woods in the world. However,pieces containing tension wood develop consider-able cup and bow and are subject to distortion dur-ing manfacture.

Caoba hondureña is one of the easiest and mostsatisfactory woods to work with, either with ma-chine or handtools, and has very little dulling ef-fect on cutting edges. However, as alreadymentioned, the presence of tension wood is trouble-some in some pieces and requires the use of verysharp cutting edges. The wood is easy to glue,takes nails and screws well, and can be given anexcellent polish by any of the accepted methods.It is one of the most satisfactory woods to slice orrotary-cut into veneer, although flitches frequent-ly develop cracks unless properly boiled. A 60-hour boiling process, starting with a coldsoaking and followed by gradual increase of tem-perature to 170° F., is recommended.

The heartwood is resistant to decay and moder-ately resistant to dry-wood termites, but it is quitevulnerable to marine borers. The sapwood isvery susceptible to both insects and decay. Logsmay be damaged by pinhole and fathead borers ifnot protected by insecticides soon after felling.

The wood possesses excellent weathering charac-teristics : only minor surface checking developswhen it is exposed to the weather without the pro-tection of paint. It is highly resistant to impreg-nation with preservatives.

Caoba hondureña is extremely strong for itsweight and was used extensively at one time forairplane propellers. It is one of the most popularcabinetwoods known, and its use is generally con-fined to the more expensive types of furniture andcabinet making, interior trim, paneling, and simi-lar products. The wood is used extensively inburial caskets, interior work of boats and ships,and turning, and in several types of musical in-

F— 495331

FIGURE 24.— Caoba hondureña: Top, flatsawned:bottom, quartersawed.

struments, particularly pianos. Its characteristiclow and even shrinkage, stability after manufac-ture, and ease of working make it particularlyvaluable for molds, dies, and patternmaking.However, the largest volume is still used for faceveneer, often with a core or backing of cedrela orother less valuable woods.

CAPA BLANCOPetitia domingensis Jacq. (verbena family, Verbenaceae)

Capá blanco is a timber of excellent quality andunusually attractive appearance (fig. 25). Thelight-brown to medium-brown heartwood is fre-quently variegated in different brownish hues oris marked by attractive darker colored waxy look-ing stripes. The sapwood is lighter brown and notclearly separated from the heartwood. The woodpossesses rather fine grains, which may be straight,somewhat wavy, or interlocked. Luster is mediumto high, growth rings are not visible, and odor andtaste are not distinctive. It is a very hard, heavy,tough, and strong wood, weighing about 49 poundsper cubic foot when air-dry and 71 pounds whengreen.

The wood air-seasons rapidly with only mod-erate degrade. Green lumber air-dries to slightlybelow 18 percent moisture content in 4 months orless under cover in the San Juan area, and degradeis limited to a moderate amount of bow and twistand very slight cupping. Other types of seasoningdefects are of little importance. Shrinkage ismoderate and uniform during seasoning, indicat-ing that the wood should be relatively stable aftermanufacture. Green lumber shrinks 1/8 inch (1.2percent) per foot across the growth rings and ¼inch (2.2 percent) per foot parallel to the growthrings during seasoning to 15 percent moisturecontent.


F-495332

FIGURE 26.— Capá blanco : Top, flatsawed ; bottom, quarter-sawed.

Capá blanco is moderately easy to work. Goodto excellent surfaces are obtained in all machiningoperations except planing, in which considerable“pickup” or torn grain occurs where interlockedgrain is present. The wood otherwise planes andmachines in other operations to a glossy smoothsurface; it glues well, takes a high polish, andaccepts nails or screws with a minimum of split-ting.

Capá blanco heartwood is moderately resistantto dry-wood termites and moderately durable incontact with the ground. Sap-staining fungi arenot troublesome in the log or during the seasoningof sawed products.

The wood is sufficiently attractive for use infurniture, cabinetmaking, turned articles, noveltyitems, interior paneling, and similar uses. Thefinished, wood resembles black walnut (Juglansnigra) of the United States in color and pleasingappearance. It has been used in the Caribbeanarea for rollers in coffee-hulling mills, for makingcarts, and for posts, poles, piling, and props. Thewood appears to be suitable for all types of agri-cultural implements, handles, sporting goods, andother products requiring an attractive, strong, anddurable wood. Knotty and low-grade materialwould be suitable for all types of light and heavyconstruction, including housing, farm buildings ofall types, bridge material, and reinforcing forconcrete work. The wood may be somewhattroublesome to peel or slice into veneer, because ofthe frequent occurrence of wavy and roey grain.

CAPÁ PRIETO

Cordia alliodora (Ruiz & Pav.) Oken (borage family, Boraginaceae)

Capá prieto is an attractive, durable, and much-used wood throughout the American tropics (fig.26). The freshly cut heartwood is light greenishbrown to olive brown in color, frequently withdarker streaks. Seasoned wood becomes a palegolden brown to brown, and the darker streaksbecome more prominent. Growth rings are de-lineated by narrow dark lines of pores, whichshow as darker colored streaks on a quartersawed(radial) surface and as wavy undulating lines on

a flatsawed (tangential) surface. Small dark raysgive the wood a lightly mottled appearance onquartersawed surfaces.

The sapwood is lighter in color than the heart-wood and not clearly delineated from it. Thegrain is generally straight, texture is fine to mostly

medium, and luster is medium to high. Odor andtaste are generally lacking except, for certaindarker colored wood from very old, large trees,which may have a distinct spicy odor. Capáprieto is a moderately heavy wood, weighing 42pounds when air-dry and 68 pounds when green.

The wood seasons at a moderate rate. Greenlumber 11/8 inches thick air-seasons to about 18percent moisture content in 4 to 5 months undercover in the San Juan area. Degrade during sea-soning is limited to a moderate amount of warp-ing. Surface checking and end splitting were notevident in the study.

Shrinkage is moderate and uniform during sea-soning. Green wood is reduced about 1/8 inch (1.0percent) per foot in width across the growth rings


and ¼ inch (2.0 percent) per foot parallel tothe growth rings on becoming air-dry.

Capá prieto saws and machines easily, with goodto excellent results. The wood’s tendency to splitwhen screws and nails are driven can be over-come by preboring and the use of proper size leadholes. It is reported to be an excellent wood toglue and to hold its place well when manufac-tured. The wood is moderately strong and hard,resembling Mexican mahogany in this respect.

Capá prieto is resistant to dry-wood termites,rating slightly above Mexican mahogany in thisrespect; it is very durable in the ground, but verysusceptible to attack by marine borers. Dark-colored wood is believed to be more durable thanthe lighter colored wood. Unpainted woodweathers well when exposed without the protectionof paint. Only very slight checking occurs afterseveral years’ exposure to the elements.

Because of its use in working, good durability,low shrinkage, and attractiveness, capá prieto isused extensively for furniture, cabinetwork, mill-work, general construction, bridge timbers, shipdecking, and general indoor and outdoor con-struction. It should also be useful for veneer,plywood, boat planking and other boat parts,turnings, and instruments. The wood’s highdurability should qualify it for many of the sameuses as cedro hembra and mahogany, but it isprobably most valuable for decorative purposes.

F— 495333

FIGURE 26.— Capá prieto : Top, flatsawed ; bottom, quar-tersawed.

CARACOLILLO

Homalium racemosum Jacq. (flacourtia family, Flacourtiaceae)

Caracolillo is an exceedingly heavy, hard, strongwood–but is not particularly attractive. Theheartwood ranges from grayish brown to reddishbrown (fig. 27). frequently with irregular streaksand patches of darker brown. The sapwood isan attractive golden yellow that merges graduallyinto the darker heartwood. The wood has finetexture, interlocked grain, and is without distinc-tive odor or taste when seasoned. Air-dry woodweighs 58 pounds per cubic foot and green woodabout 72 pounds at 50 percent moisture content.

The wood seasons at a moderate rate, reachingan air-dry moisture content of about 18 percentin 6 months under cover in the San Juan area.Moderate degrade occurs during seasoning in theform of very slight cup, end and surface check-

596033 O–61— — 4

ing, and crook, slight twist, and moderate bow.Directional and volumetric shrinkage is moderatefor a wood of caracolillo’s density. Green woodundergoes about 1/5 inch (1.8 percent ) shrinkageper foot in width across the growth rings and 3/8inch (3.1 percent) per foot in width parallel tothe growth rings in seasoning to 15 percent mois-ture content. Caracolillo is reported to be stableafter manufacture.

Caracolillo is moderately difficult to machinebecause of its density, but it can be worked to aglossy smooth finish in all machining operations.However, the wood has poor resistance to screwsplitting unless adequate-sized lead holes are used.It takes stain, paint, and varnish satisfactorilywithout a filler and should also glue satisfactorily.


The heartwood has considerable resistance todry-wood termites, rating well above Mexican ma-hogany in this quality.durability rating in the ground or when sub-.

Although the wood’s

merged in teredo-infested waters is not known, itis presumably not high.

Caracolillo is suitable for flooring, furniture,cabinetwork, turning, and other decorative uses.The wood’s high strength, hardness, and straightbut interlocked grain indicates that it would besuitable for tool handles, sporting and athleticgoods, agricultural implements, boat frames, keelsand underwater structural members of boats, andsimilar uses. It is also suitable for heavy con-struction of all types wherever a heavy, strongmaterial is required.

F— 495334

FIGURE 27.— Caracolillo : Top, flatsawed ; bottom, quar-tersawed.

CASUARINA

Casuarina equisetifolia L. (casuarina family, Casuarinaceae)

Casuarina is commonly called Australian-pinebecause of its needlelike leaves and its native habi-tat in Australia. The tree is planted extensivelyin the lower mountain regions of Puerto Ricowhere it makes excellent growth. Trees fre-quently grow to 15 inches in diameter and 140feet tall in 15 to 20 years after planting. Clearboles up to 100 feet long are common on thebetter sites.

The wood is very hard and heavy, and excep-t ionally strong and tough. Its heartwood is adull reddish brown, occasionally with dark brownto almost black streaks at irregular intervals (fig.28), andsapwood.

not easily separated from the pinkishThe wood has a very fine texture and

medium luster, and tightly interlocked grain ischaracteristic. Growth rings are not easily dis-tinguished. Air-dry wood weighs about 64pounds per cubic foot and green wood 72 poundsper cubic foot at 42 percent moisture content.

The wood dries at a moderate rate and under-goes considerable degrade during the process.Green lumber 11/8 inches thick air-dries to about18 percent, moisture content in 5 months undercover in the San Juan area. Seasoning is accom-panied by severe cupping and surface checkingand lesser amounts of other external defects.Some casehardening may also occur under theusual drying conditions.

Seasoning is accompanied by heavy and rela-tively uneven shrinkage. Green wood shrinks atthe rate of 1/4 inch (2.4 percent) per foot in widthacross the growth rings and 2/3 inch (5.8 percent)per foot across the growth rings in drying to 15percent moisture content. However, longitudinalshrinkage (0.04 percent) is surprisingly low for awood with such tightly interlocked grain.

Casuarina logs are very difficult to saw in smallcircular sawmills. Circular saws tend to heat,


chatter, and veer off course, producing lumber soconsistently offsize that it has little, if any, marketvalue. Because of its density and hardness, air-dry casuarina lumber is also difficult to machine.However, machined surfaces are usually of fairlygood quality.

Some difficulty is encountered in machining, be-cause of the frequent “pickup” that occurs plan-ing and the tearing and roughened surfaces thatdeveloped in turning under normal operating con-ditions. Where the defects are not present, thewood machines to a glossy smooth surface. It israted as a good wood for boring and mortising,and it sands to a very smooth finish. Because ofits tightly interlocked grain, it has exceptionallygood resistance to screw splitting for a wood of itshigh density. Well-finished wood is attractive butlacks the distinctive figure preferred in furniture,cabinet work, and other decorative uses.

Casuarina is very susceptible to damage by dry-wood termites and only slightly durable in theground. But, on the basis of short-term tests inPuerto Rico, it can be effectively and simplytreated with preservatives by the hot and coldbath process.

Casuarina is used principally in Puerto Rico forfence posts and poles, tobacco barns, and otherstructures. It should be suitable for utility polesand piling in nonteredo areas and for many otheruses where an extremely hard, dense, wood is re-quired. Because of extreme difficulty in sawing,casuarina is limited mainly to uses for which roundor hewn material is acceptable, although it maybe feasible to square logs in the mill for use inheavy construction.

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FIGURE 28.— Casuarina: Top, flatsawed ; bottom,quartersawed.

CEDRO HEMBRA (CENTRAL AMERICAN CEDAR)Cedrela odorata L. (mahogany family, Meliaceae)

Cedro hembra is the most important timber forgeneral domestic use in tropical America, but thesupply is very limited in Puerto Rico. Most of thelocal logs are short and of small diameter. Boththe tree and wood are widely known as Spanishcedar or Central American cedar.

The heartwood (fig. 29) is pinkish to reddishbrown when freshly cut, becoming a uniform redor dark reddish brown, occasionally with a pur-plish tinge, after exposure. The darkest coloredwood comes from the drier exposures. The sap-wood is whitish gray or pinkish and sharply de-lineated from the heartwood. Growth rings areclearly marked by narrow lines of darker pores,which are visible on both quartersawed and flat-sawed surfaces. A pleasing figure is provided bythese scattered vessel lines that stand out on anotherwise plain surface. The luster is fairly high,often described as a satiny sheen, and the textureis medium and uniform. The wood is straightgrained and easily split. A cedarlike odor is

usually apparent, and at times a bitter taste isevident in seasoned wood.

Two distinct types of wood are recognized insome areas and may be represented in Puerto Rico.One is a dark variety that is more straight grained,coarser textured, and has more volatile oil; theother is lighter colored, not so straight grained,and has finer texture, lower luster, and less vola-tile oil. The weight of the wood varies consider-ably according to site, age of tree, and rapidity ofgrowth. Wood cut in Puerto Rico averaged 34pounds per cubic foot when air-dry and 51 poundsin the green condition.

Cedro hembra seasons at a rapid rate with onlyminor degrade. Green 11/8-inch lumber air-seasonsto 20 percent moisture content in 4 months undercover in the San Juan area. The air-dry moisturecontent of 20 percent is unusually high for a woodof moderate density. Seasoning degrade is usuallylimited to a small amount of warping in the formof cup, bow, and twist. Surface checking and


F— 495336

FIGURE 29.— Cedro hembra : Top, flatsawed ; bottom,quartersawed.

other external defects were not observed in thestudy.

In kiln-seasoning, some pieces are liable to dis-tort or collapse, and splits may occur along knotsunless low temperatures are used. Successful kilnschedules for this species have been developed bythe Forest Products Research Laboratory, Prin-cess Risborough, England, and by the IndonesianForest Research Institute.

Cedro hembra undergoes relatively low and uni-form shrinkage during seasoning and stays inplace very well after manufacture. Green woodshrinks 1/4 inch (2.1 percent) per foot in widthacross the growth rings and 1/3 inch (3.0 percent)per foot width parallel to the growth rings in sea-soning to 15 percent moisture content.

The wood works very easily with both hand andpower tools, giving good results in planing, shap-ing, mortising, and sanding. It is a fairly goodwood to turn but is difficult to bore; torn androughened grain occur in these operations. Thepresence of gum in some material gives trouble inpolishing but, in general, the wood stains andpolishes *beautifully after suitable filling. It hasgood nail- and screw-holding properties, is easyto glue, and is a fairly good bending wood. Cedrohembra is very popular in the veneer and plywoodindustry, because it peels cold, dries exceptionallywell, and has good glueing properties. A slighttendency for wooly surfaces to occur in veneeringIS overcome by maintaining sharp edges on all cut-ting surf aces.

Cedro hembra is slightly inferior to Hondurasmahogany in most strength properties but is, ingeneral, a relatively strong wood for its weight.It is considered more resistant to dry-wood ter-mites than Honduras mahogany, rating resistantas compared to moderately resistant for that spe-cies. However, the wood is sometimes attacked bypinhole borers and has low resistance to attack bymarine borers. It is rated moderately durable todurable in resistance to decay in contact with theground. Both logs and lumber are subject to sap-staining fungi. The wood possesses excellentweathering properties when exposed to the ele-ments without the protection of paint.

In the countries where it grows, cedro hembrais the most extensively used wood for general con-struction and carpentry of all types, and for faceand core veneer for decorative and utility gradesof plywood. The heavier grades are suitable forthe same uses as Honduras mahogany. The woodIS also particularly well suited for patternmaking,venetian blinds, decking and planking for smallboats, musical instruments, doors, paneling, shin-gles, flooring, and cigar boxes. It is used exten-sively in the American tropics for furniture,millwork, boat parts, both interior and exteriordecoration, and for genera l and durableconstruction.

CEIBACeiba pentandra (L.) Gaertn. (bombax family, Bombacaceae)

Ceiba, also known as the silk-cotton tree, is anexceedingly lightweight wood (fig. 30) resembling

wood in its natural state is a very light brown, but

guano (balsa) in appearance, and at 17 poundsit is nearly always turned to blue gray by sap-

per cubic foot air-dry weighs the same as thatstaining fungi. The sapwood is the same color

species. Green wood weighs 50 pounds per cubicand difficult to distinguish from the heartwood.

foot at 24 percent moisture content. The dryThe wood has coarse texture, straight grain, andlow luster; it is without distinctive odor or taste.


Green wood air-seasons to about, 18 percentmoisture content in 6 months under cover in theSan Juan area. This moderately rapid rate ofseasoning is accompanied by moderate degrade inthe form of a small amount. of warping andmoderate surface checking.

Shrinkage is low but somewhat uneven duringseasoning. Green wood is reduced about 1/10inch (0.8 percent) per foot across the growthrings and 1/3 inch (3.2. percent) along the growthrings in the air-drying process. Its longitudinalshrinkage of 0.22 percent is fairly high for a woodwithout interlocked grain.

Ceiba machines easily but not satisfactorily. Itcan be sawed almost, without effort but tends todevelop fuzziness in both ripping and crosscut,-ting. The wood gives excellent, results in plan-ing and sanding, and in resistance to screwsplitting, but it is difficult to shape, bore, turn,and mortise because of its tendency to tear in theseoperations.

Both the logs and lumber are very susceptibleto attack by insects and decay. Logs left in theforest for any length of time discolor and decayrapidly and are very quickly riddled by insects.The lumber, as mentioned earlier:, is almost alwaysturned blue gray by sap-staining fungi unlessdipped in a fungicide solution soon after sawing.

The tree is better known for its kapok than forthe soft, nondurable wood it. produces. The flosssurrounding the seeds of this tree is collected bynatives in Central America (rarely in PuertoRico) and sold on the export market as kapok.This product is used extensively in buoys, lifebelts, life-saving jackets, and for stuffing pillows,cushions, and similar articles.

Ceiba possesses low strength in proportion toits low density but is still about twice as strongas guano (balsa). The wood is suitable for boxes,slack cooperage, toys, light construction, and

F–495337

FIGURE 30.— Ceiba : Top, flatsawed ; bottom, quartersawed.

numerous other products requiring a light, soft,easily worked wood. Ceiba’s similarity to guanomay qualify it for many uses where the heaviergrades of this wood are acceptable. It should alsobe acceptable for patternmaking, plywood cores,and utility-grade plywood.

CUCUBANOGuettarda laevis Urban (madder family, Rubiaceae)

Cucubano is an attractive and useful wood butgenerally available only in small-diameter logsfrom the Puerto Rican forests. The heartwood(fig. 31) is an attractive pale yellowish brown togolden brown, often streaked or variegated with adarker brown. The sapwood is cream to very lightbrown and not clearly delineated from the heart-wood. The wood has good luster, fine texture, andgenerally straight to occasionally interlockedgrain. Growth rings are very faintly marked bysomewhat darker colored tissue. Odor and tasteare not distinctive in seasoned wood.

The wood is moderately hard, strong, and heavy,weighing 50 pounds per cubic foot when air-dryand 69 pounds when green. On the basis of testsof closely related species, cucubano possessesstrength properties commensurate with its weightand somewhat higher than those for oak, but it isconsidered a relatively poor bending wood.

The wood seasons at a moderate rate with amoderate amount of degrade. Green lumber air-dries to about 18 percent moisture content inapproximately 6 months under cover in the SanJuan area. A moderate amount of surface check-


F— 445338

FIGURE 31.— Cucubano ; Top, flatsawed ; bottom, quarter-sawed.

ing and warping occurs during the seasoningprocess.

Shrinkage is relatively uniform and not exces-sive for a wood of cucubano’s density. Green woodshrinks ¼ inch (2.0 percent) per foot in widthacross the growth rings and ½ inch (4.0 percent)per foot in width parallel to the growth ringsin drying to 15 percent moisture content.

Cucubano works easily with either power orhand tools, with generally satisfactory results inmost operations. However, the wood has a tend-ency to crush and crumble in boring, and itscratches readily in sanding unless fine abrasivepaper is used. Because of its generally verystraight and uniform grain and high density, it isalso easily split by nails or screws unless properlyprebored. It takes a good polish without the useof a filler.

Cucubano is very susceptible to dry-wood ter-mites and probably is not durable in the groundor when exposed to marine borers. The wood isseldom used in Puerto Rico, but it appears to besuitable for tool handles, fancy boxes, brush backs,small dimension turnery parts, and other items re-quiring a dense, close-grained, uniform wood. Itshould also be equally useful for furniture, cabi-network, farm implements, interior trim, paneling,and novelty items, and it may be suitable fordecorative veneer and plywood. Cucubano isequally well fitted for exterior construction, pilingin nonteredo areas, bridgework, and other similaruses requiring a very heavy, hard, and strongwood.

CUPEY

Clusia rosea Jacq. (mangosteen family, Guttiferae)

Cupey is a heavy, hard, strong wood of rathercommon appearance (fig.32). The heartwood isreddish brown in contrast to the lighter coloredsapwood, which merges gradually into the heart-wood. The wood has medium luster, medium tofine texture, and straight grain. Growth rings arenot evident, and seasoned wood is without distinc-tive odor or taste. Air-dry wood weigh 52pounds per cubic foot and green wood 72 poundsper cubic foot at 71 percent moisture content.

The wood air-seasons at a moderate rate. Greenlumber 11/8 inches thick air-seasons to 17 percentmoisture content in about 6 months under coverin the San Juan area. A moderate amount ofdegrade occurs during seasoning in the form ofwarp and surface checking. Surface checks areoften fairly deep, particularly around knots, andsome casehardening and collapse may also occur.

Cupey undergoes moderately high shrinkageduring seasoning, compared with other woods ofsimilar density. Green lumber shrinks at the rateof ¼ inch (2.1 percent) per foot in width acrossthe growth rings and 9/16 inch (4.7 percent) perfoot in width parallel to the growth rings whenseasoned to 15 percent moisture content. Sap-stain fungi are not troublesome during seasoning.

Cupey is moderately difficult to saw and ma-chine because of its great density and hardness,yet it produces fair to good surfaces in all opera-tions. However, some trouble is encountered inplaning and boring: tearing and crushing occurfrequently. The wood takes screws satisfactorilywithout splitting and should glue and polish well.

Cupey is very susceptible to attack by pinholeborers, dry-wood termites, and other insects. It is


probably poorly resistant to decay and attack bymarine borers, although specific information is notavailable.

Because the wood is not particularly attractive,it is used principally for fuel, fence posts, andrural construction. However, cupey is suitable forboth light and heavy construction, cheap gradesof furniture, farm implement parts, tool handles,and other uses requiring a heavy, strong wood.

F–495339

FIGURE 32.— Cupey : Top, flatsawed ; bottom, quartersawed.

ESPINO RUBIAL

Zanthoxylum martinicense (Lam.) DC. (rue family, Rutaceae)

Espino rubial, also called Martinique prickly-ash, belongs to the satinwood group but lacks thecharacteristic attractiveness and workability ofcertain other woods in the genus. The heartwoodis creamy to light brown in color (fig. 33), some-times with a pronounced greenish blue, and it isnot readily distinguished from the lighter coloredsapwood. Growth rings are clearly marked onthe end grain b zones of larger and lighter col-ored vessels. The wood is without distinctive fig-ure except for an inconspicuous feather pattern onflatsawed surf aces and very fine pencil striping onthe quartersawed surfaces, both resulting from thering-porous nature of the wood. The wood ismoderately heavy and hard, has medium to finetexture, straight to irregular grain, good luster,and a rancid odor when freshly worked. Air-drywood weighs about 35 pounds per cubic foot andgreen wood 53 pounds.

The wood seasons rapidly but undergoes rathersevere degrade during the process. Green 11/8-inch lumber air-dries to 18 percent moisture con-tent in slightly over 4 months under cover.Moderate amounts of bow, twist, and crook, andvery slight cup and surface checking, occur dur-ing the seasoning process.

Espino rubial undergoes moderate and uniformshrinkage during seasoning. Green wood shrinks5/32 inch (1.5 percent) per foot in width across thegrowth rings and 10/32 inch (2.6 percent) per footin width along the growth rings in seasoning to15 percent moisture content. Molds and sap-staining fungi are not particularly troublesomeduring the seasoning process.

The wood works easily with either hand orpower tools but produces only fair to poor resultsin most. operations. Torn grain and coarse fuzzi-ness are common in shaping and turning; tearing


and crushing are troublesome in boring and mor-tising; and considerable scratching and fuzzinessoccur in sanding unless a very fine abrasive paperis used. However, the wood has good resistanceto screw splitting. The best machined surfacesare obtained when very sharp and thin cuttingedges are used along with an increased spindlespeed and a reduced rate of feed.

Espino rubial is very susceptible to dry-woodtermites, pinhole borers, and other insects. It isnot believed to be durable in contact with theground, although specific information as to itsvulnerability to decay is not available.

Because of its plain appearance, difficulties inseasoning, and only fair working qualities, espinorubial is best suited for boxes, crates, general car-pentry, low-grade furniture, light construction,concrete forms, and similar uses. However, withconsiderable care in seasoning and machining, thebetter grades of this species could be used forinterior trim, doors, window frames, and othertypes of interior construction. It might also besuitable for utility veneer and core stock.

F— 495340

FIGURE 33.— Espino rubial: Top, flatsawed ; bottom,quartersawed.

EUCALIPTOEucalyptus robusta J. E. Smith (myrtle family, Myrtaceae)

Small to occasionally medium-size logs ofeucalipto, known as swamp mahogany or swampmessmate in its native Australian habitat, areavailable from the extensive plantings of thisspecies in the high mountainous rain forests ofPuerto Rico. The tree is also known as beakpodeucalyptus in some areas. Lops of other Eucalyp-tus species growing on the island may occasionallybe marketed in combination with E. robusta, andthey have the same general properties and uses asthat species.

The heartwood of eucalipto is salmon to lightreddish brown when seasoned (fig. 34), oftenmottled with brown streaks and patches, and isindistinct from the light-brown sapwood. Faintgrowth rings are evident on the end grain. Thewood is coarse in texture, quite lustrous, and fairlystraight grained, although some interlocked grainmay occur. The timber is hard, strong, stiff, and

elastic, weighing 42 pounds per cubic foot whenair-dry. Green wood weighs 69 pounds per cubicfoot at 115 percent moisture content.

Like most other eucalypts, this wood is diffi-cult to season. Carefully stacked 11/4-inch lumberrequires about 6 months to reach an air-dry mois-ture content of 19 percent under cover in the SanJuan area. Considerable degrade develops duringseasoning, mostly from warp, although a smallamount of surface and end checking may occur.

The mood undergoes unusually great and unevenshrinkage during seasoning for a wood of itsdensity. Green wood shrinks more than 3/8 inch(3.5 percent) per foot in width across the growthrings and slightly over 11/8 inches (9.7 percent)per foot in width parallel to the growth rings inseasoning to an air-dry moisture content of 15percent.


The wood works easily with both hand andmachine tools and gives fairly good results inmost operations. There is, however, a tendencyfor the wood to crush and tear in boring and forscratches to show clearly in sanding unless fineabrasives are used. Eucalipto possesses unusualresistance to splitting when screws are driven,and it should take nails equally well. After ap-propriate fillers are used, the wood can be finishedto a smooth, satiny appearance.

The wood is considered durable in the ground,but it is very susceptible to attack by dry-woodtermites in Puerto Rico. On the basis of ex-perience with other closely related species, thiswood is probably highly resistant to the penetra-tion of preservatives.

This species is used in Australia for general con-struction work, especially in contact with theground. It, should be useful in Puerto Rico for alltypes of posts, utility poles, and light and heavyconstruction, and for other purposes requiring astrong, durable wood. The difficulty of seasoningsawed material and its lack of attractivenessindicate that the wood is most usable in the roundor squared form. Yet, it appears to be suitable forflooring, boxes, crates, and cheap furniture if satis-factory methods of seasoning can be developed.The wood is sufficiently strong and durable forpiling in nonteredo areas, but it requires the useof caps during driving operations. Round orsquared timbers would also be very serviceable forsupports and bracing in concrete constructionwork.

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FIGURE 34.— Eucalipto : Top, flatsawed ; bottom, quarter-sawed.

GRANADILLO

Buchenavia capitata (Vahl) Eichl. (combreturn family, Combretaceae)

Granadillo is a very attractive timber of goodquality and many potential uses. The heartwood(fig. 35) is light yellow to golden brown anddistinct but not clearly separated from the pale-yellow sapwood. The wood has high luster,straight to more frequently roey gram, mediumtexture, and a faint, odor and mildly astringenttaste when green. Dry wood is without distinctiveodor or taste. Growth rings are marked by nar-row bands of darker pores, showing as an attrac-tive ribbon stripe on quartersawed surfaces. It ismoderately hard and strong, weighing 46 poundsper cubic foot when air-dry and 68 pounds whengreen. Air-dry granadillo weighs about the sameas white oak and is similar to it in most strengthproperties.

Green lumber air-seasons rapidly with only avery small amount of degrade in the form ofslight bow and twist. Green lumber seasons to anair-dry moisture content of 18 percent, in slightlyless than 4 months under cover in the San Juanarea.

Granadillo shrinks very little during season-ing. Green lumber loses 1/8 inch (1.1 percent) perfoot, in width across the growth rings and 5/16 inch(2.5 percent) per foot along the growth rings indrying to an air-dry moisture content of 15percent.

The wood machines with moderate difficulty be-cause of its hardness, but it produces good sur-faces in all operations even though some tearing


may result, from irregular grain. It is reportedto finish well and to take a beautiful high satinypolish.

The wood is rated more resistant to dry-woodtermites than Honduras mahogany or cedrohembra and is fairly durable in the ground. Sap-stain fungi or insects are not troublesome duringseasoning.

Granadillo’s uniform color, attractiveness, andgood machining properties make it highly ac-ceptable for all types of furniture and cabinet-work. It is also recommended for house framing,flooring, construction work of all kinds, plywood,and railway sleepers after preservative treatment.Because of its attractiveness, it is recommended fordecorative veneer and plywood. The wood shouldalso be suited for interior trim, boat. building,boxes and crates of all types, turnery, and manyother uses requiring a strong, attractive wood withgood durability.

F— 495342

FIGURE 35.— Granadillo: Top, flatsawed ; bottom,quartersawed.

GUABA

Inga vera Willd. (legume family, Leguminosae)

Guaba is a wide spreading, low branching treethat is planted extensively for shade and protec-

similar density, guaba is considered a moderately

tion on coffee plantations. It produces short logshard, strong, tough wood with good resistance to

of small to medium diameter. The wood is seldomsplitting and good bending properties.

used except for charcoal and fuel, but it has suf-Guaba air-seasons rapidly with a moderate

ficient strength for many other uses. Also, it isamount of degrade, mostly in the form of bow.

moderately attractive (fig. 36) and machines well. Careful piling might eliminate most of this de-The heartwood is pale brown to golden brown grade. Green lumber air-seasons to about 19 per-

with longitudinal streaks or patches of darker cent moisture content in 3 months under cover inbrown that in turn are frequently shaded with the San Juan area, undergoing moderate and uni-hues of green or yellow. The indistinct sapwoodis whitish in color.

form shrinkage during the process. Green woodThe wood is coarse in texture, shrinks at the rate of 1/8 inch (1.0 percent) per foot

fairly lustrous, straight to frequently roey grained, in width across the growth rings and 1/4 inch (2.0and without distinctive odor or taste. Guaba is percent) per foot parallel to the growth rings incomparable to Douglas-fir in density, weighing 44pounds per cubic foot when air-dry and 62 pounds

seasoning to 15 percent moisture content.

in the green condition. Compared to woods ofThe wood saws and machines easily and with

good results in all operations except shaping.


Torn and raised grain is particularly troublesomein this operation.

Guaba is very susceptible to damage by termitesand other insects and to decay when in contact withthe ground. Sap-staining fungi are apt to betroublesome in the log or freshly sawed lumber.

Because of its good strength properties, general-ly good machining characteristics, and moderateattractiveness, guaba is suitable for utility furni-ture, boxes, crates, light construction of all types,and general carpentry. After preservative treat-ment, it should also be useful for railway ties,posts, poles, bridge timbers, and other miscellane-ous exterior uses.

F–495343

FIGURE 36.— Guaba : Top, flatsawed ; bottom, quarter-sawed.

GUAJÓNBeilschmiedia pendula (Sw.) Benth. & Hook. f. (laurel family, Lauraceae)

The heartwood of guajón is a pinkish brown,often with widely spaced blackish lines at irregu-lar intervals (fig. 37), and it is readily distin-guished from the pale-brown sapwood. Numer-ous pores are visible as fine scratches on flatsurfaces, giving the wood a somewhat attractiveappearance; The wood has medium texture,straight, grain, medium luster, and is without dis-tinctive odor or taste. Growth rings are notclearly defined. Guajón is moderately hard,strong, and heavy, weighing 41 pounds per cubicfoot when air-dry and 64 pounds when green.

The wood air-seasons slowly with only a minoramount of warping and no visible surface check-ing. In the tests, green lumber 11/8 inches thickrequired 10 months or longer to reach an air-drymoisture content of 20 percent. Guajón is accord-ingly the slowest to air-dry but one of the least

refractory of the commercial hardwoods growingin Puerto Rico.

Shrinkage during seasoning is moderate anduniform. Green wood shrinks at the rate of ¼inch (2.0 percent) per foot of width across thegrowth rings and 7/16 inch (3.6 percent) per footalong the growth rings in seasoning to 15 percentmoisture content.

Guajón` works easily, but with varying results.It is rated “good” in planing and shaping; “fair”in turning, mortising, and sanding; and “poor’!in boring. Rough surfaces result from torn grainin turning; tearing and crushing occur along thesides of the holes in boring and mortising; andscratches are clearly visible in sanding unless afine abrasive paper is used. However, surfaceswell sanded with fine abrasives are very smoothand take a good polish. The wood has good resist-


ance to splitting when screws are driven and pre-sumably will take and hold nails satisfactorily.

Guajón is very susceptible to damage by dry-wood termites. Although it is generally con-sidered to be highly durable when in contact withthe ground, authentic tests proving this point arelacking.

The wood is used for shipbuilding, general con-struction, flooring, furniture, cabinetmaking, andcarpentry. It is also recommended for decorativeplywood, handles, interior trim and paneling,agricultural implements, and other uses for whichmaple and birch are used.

F— 495344

FIGURE 37.— Guajón : Top, flatsawed ; bottom,quartersawed.

GUAMÁ

Inga laurina (Sw.) Willd. (legume family, Leguminosae)

Guamá is one of the trees planted extensivelyin Puerto Rico and other Caribbean areas to shadeand protect coffee plantations. Because of its char-acteristic low branching and the coffee-growers’preference for young thrifty trees, only short,small- to medium-size logs are available. Thewood is seldom used except for fuel and charcoal,yet it is as attractive and serviceable as manyrecognized furniture woods.

The heartwood (fig. 38) is a pale reddish brown,often streaked with a darker brown, and not clearlydistinguished from the lighter colored sapwood.Luster is medium to high, and the texture is coarse.The grain is straight to more frequently roey,showing as ribbon stripes on flatsawed surfaces.Odor and taste are lacking in seasoned wood. Thewood is medium in density, weighing 46 poundswhen air-dry as compared with 48 pounds for

white oak and 44 pounds for sugar maple. Greenwood weighs 67 pounds per cubic foot. It is mod-erately hard, strong, and tough, comparing favor-ably in strength properties with other woods ofsimilar density.

Guamá seasons rapidly with moderate degradein the form of very slight twist and crook and mod-erate bow. Green lumber air-seasons to about 18percent moisture content in approximately 4months under cover in the San Juan area. Thewood undergoes low and uniform shrinkage dur-ing seasoning and is stable after manufacture.Green wood shrinks at the rate of about 1/5 inch(1.6 percent) per foot in width across the growthrings and 1/3 inch (2.7 percent) per foot in widthparallel to the growth rings in seasoning to 15percent moisture content.

The wood works easily and with generally goodresults except that some torn grain occurs inpieces with roey grain, particularly in planing andshaping, where only fair results are obtained.The wood finishes satisfactorily and takes lacquer,varnish, or paint very well after a grain filler isapplied. It also has good resistance to screwsplitting, and it glues satisfactorily but, is some-what difficult to nail unless prebored.

Guamá is very susceptible to termite damage anddecay. Logs are also quickly attacked by pinholeborers if not converted into lumber soon afterfelling. Sap-staining fungi are not troublesomein either the logs or green lumber.

Guamá is suitable for many of the same pur-poses as oak, such as furniture, cabinetwork, toolhandles, interior trim, general construction, crates,boxes, and flooring. After treatment with pre-servatives, it should be useful for posts, railwaycrossties, bridge timbers, and other exterior work.It has also been recommended for both decorativeand utility-grade veneer and plywood.

GUANO (BALSA)Ochroma pyramidale (Cav.) Urban (bombax family, Bombacaceae)


F–495345

FIGURE 38.— Guamá : Top, flatsawed ; bottom,quartersawed.

Guano, also called balsa, is the lightest com-mercial wood used today. Good-quality light-weight wood of this species is increasingly moredifficult to obtain and correspondingly higher incost as the Central American supply is depleted.Unfortunately the wood growing in Puerto Ricois generally somewhat heavier than the exportgrade accepted by importers; it is somewhat lessbuoyant and not so efficient for insulation againstheat and sound as the export grade.

The heartwood is pale brown or slightly tingedwith red. The sapwood, which provides most ofthe commercial wood, is nearly white or oatmealcolored, often with a yellowish or pinkish hue.The grain is very coarse (fig. 39), straight, anduniform. The wood is odorless, tasteless, and hasa rather high, silky luster and velvety feel. In thetests, wood from trees grown in Puerto Rico aver-aged 17 pounds per cubic foot when air-dry and27 pounds when green as compared with 27 poundsfor air-dry western white pine of the United

States. The commercial grade of guano used byindustry weighs 8 to 14 pounds, with an averageof about, 10 pounds per cubic foot.

in the study.

The Puerto Rican guano air-seasoned at amoderate rate when closely piled, reaching a mois-ture content of about 17 percent in 5 to 6 monthsunder cover in the San Juan area. Moderate de-grade occurs during seasoning in the form ofslight, to moderate cup, slight bow and twist, anda very slight amount of crook, surface checking,and end checking. Casehardening was not evident

The wood is reported to air-season satisfactorilyby end-racking in Ecuador where 4½ -inch thickstock seasons below 20 percent moisture contentin 14 to 21 days. Guano is reported to be some-what, difficult, to kiln-dry; is has a tendency tosplit, warp, and caseharden; and to be practicallytoasted, in the kiln-drying process.

Guano undergoes considerable shrinkage duringseasoning for a wood of its density; afterwards itloses or gains moisture quickly with changes in


Guano is easy to work with sharp, thin-edgedpower or hand tools, with practically no dullingeffect on cutting edges. Thin-gage saws are recom-

of 1/6 inch (1.3 percent) per foot, in width acrossthe growth rings and 9/16 inch (4.7 percent) perfoot in width parallel to the growth rings in sea-soning to 15 percent moisture content. The longi-tudinal shrinkage of 0.11 percent is also moder-ately high for wood of guano’s low density.

mended because thick-edged tools produce woolysurfaces and cause the wood to crumble, particu-larly in planing. In most machining operationsthe wood is fairly difficult to work without the oc-currence of fuzziness and crumbling. Guano takesnails and screw readily but is too soft to hold them.

Inasmuch as the wood glues satisfactorily, thisis the most satisfactory method of fastening orholding it in place. Guano can be stained satis-factorily and polished fairly well, but it absorbsmuch of the material during the process. The useof a filler is necessary if a good surface coating isdesired.

F— 495346

FIGURE 39.— Guano (balsa) : Top, flatsawed; bottom,quartersawed.

atmospheric conditions, but fortunately undergoesrelatively small dimensional changes. Water-proofing treatments with paraffin, commercialwater repellents, varnish, or glossy paint are effec-tive in reducing the hygroscopicity of the wood.The ratio of tangential to radial shrinkage is high,indicating that considerable stress may occurduring seasoning, leading to the development ofseasoning defects. Green wood shrinks at the rate

GUARAGUAOGuarea trichilioides L. (mahogany family, Meliaceae)

Guaraguao, also called American muskwood, isfrequently planted for shade and protection in

aromatic, but no distinctive odor or taste is evi-

coffee plantations, producing short logs of mediumdent in seasoned wood. It is a moderately heavy

to large diameter. The very attractive heartwoodwood, weighing 38 pounds per cubic foot, air-dry

(fig. 40) is pinkish to red when first cut, turningand 71 pounds green. Guaraguao is strong and

a light reddish brown after seasoning and ex-tough for its weight in comparison with other

posure. The whitish to brownish sapwood iswoods of similar density.

distinct but not clearly demarcated from the heart-Lumber of this species seasons slowly, requiring

wood. The luster is rather low, texture isabout 8 months under cover in the San Juan area

medium, and grain is straight. Green wood isto air-season 11/8-inch material to 19 percentmoisture content. Seasoning is accompanied by

Termites, marine borers, and decay organismsreadily attack the wood and cause severe damage.Despite its softness and porosity, guano is fairlyresistant to impregnation with preservatives, al-though both heartwood and sapwood can besatisfactorily treated by either pressure or non-pressure methods. However, pressure treatmentoften causes collapse of the cell walls.

The strength of guano varies directly with itsdensity. In general, the wood is stronger for itsweight than other timbers. The slow-growingand consequently heavier grade of guano growingin Puerto Rica is suitable for certain types offruit and vegetable containers, novelties, toys, andtemporary boarding or cement, forms. Materialtreated against termite attack should also be ade-quate for cores of flush doors and other light con-struction. In general, guano can be used for manypurposes for which the heavier grades of com-mercial balsa are commonly acceptable, and as asubstitute for white pine where high strength andstability are not essential.


a moderate amount of warping, and sapwoodpieces tend to distort more than heartwood pieces.No surface checking was evident in the tests.

The wood undergoes moderately and fairlyuniform shrinkage during seasoning. Greenwood shrinks 1/6 inch (1.4 percent) per foot inwidth across the growth rings and 7/16 inch (3.7percent) per foot in width parallel to the growthrings in seasoning to 15 percent moisture content.The wood is reputed to be stable after manu-facture.

Guaraguao saws and machines easily and wellin all operations except boring. In this operationit has a tendency to tear and crumble. Silica ispresent in the wood but has no detrimental effectson its machining properties. The wood takes ahigh lustrous finish with either varnish orlacquer.

Guaraguao has good resistance to dry-woodtermites and is durable in the ground. The heart-wood is considerably more resistant, to dry-woodtermites than Honduras (Mexican) mahogany butrates somewhat, below West. Indies mahogany inthis characteristic. The heartwood is highly re-sistant to impregnation with preservatives but thesapwood responds well to pressure treatment.

Because of its attractiveness, good strength,durability, and favorable working properties,guaraguao is well suited for furniture and cabinet-work, turnery, interior trim, and general construc-tion and carpentry. Guaraguao has strength andworking properties similar to those of white oakand is suitable for most of the same purposes.For veneer, the wood may be similar to other re-lated species that. are suitable but. require consider-able steaming for either rotary or slicingoperations.

F–495347

FIGURE 40.— Guaraguao : Top, flatsawed ; bottom, quarter-sawed.

GUAYABOTA

Eugenia stahlii (Kiaersk.) Krug & Urban (myrtle family, Myrtaceae)

Guayabota is an attractive grayish-brown woodwith a very mild and pleasant scent but withoutdistinctive taste. Growth rings are marked bynarrow bands of darker colored wood (fig. 41),which shows on the quartersawed surface as closelyspaced, darker colored lines. The pinkish-brownsapwood is clearly distinct from the heartwood.The wood has fine texture, irregular grain, andmedium to low luster. It is very hard, heavy,tough, and strong, weighing 57 pounds per cubicfoot air-dry and 72 pounds green.

The wood is moderately difficult to season.Green lumber air-dries at a moderate rate, reach-ing 18 to 19 percent moisture content in 5 to 6months under cover in the San Juan area. A mod-erate amount of warping and a small amount ofsurface checking occur during seasoning.

High but uniform shrinkage occurs during sea-soning. Green wood shrinks at the rate of 1/3 inch(2.8 percent) per foot in width across the growthrings and 2/3 inch (5.8 percent ) per foot in widthparallel to the growth rings in seasoning to 15percent moisture content. However, its longitudi-nal shrinkage of 0.06 percent is low for a woodwith irregular grain.

Guayabota is moderately difficult to work be-cause of its hardness, but it machines to a verysmooth surface in all operations except, sanding.The wood is rated “poor” in sanding on the basisthat scratches show clearly unless very fine abra-sive paper is used. Yet a glossy-smooth surfacecan be obtained when 4/0 or 5/0 grit paper is used.Guayabota is extremely susceptible to screw split-ting, rating lowest of the woods tested. Preboring


proper size lead holes for screws or nails is veryessential in this wood. The smooth surfaces ob-tained in machining should finish and polishsatisfactorily.

Guayabota is very susceptible to dry-wood ter-mites and is reported to be variable in decay re-sistance, with the darker colored specimens beingthe most durable.

This wood is suitable for furniture, cabinetwork,turnery, carving, interior trim, tool handles, agri-cultural implements, boat building, and both lightand heavy construction. Quartersawed materialis the most attractive and should be used where ap-pearance is important. After proper preservativetreatment, guayabota would be acceptable forposts, poles, piling, and other exterior uses aboveand below ground.

F— 495348

FIGURE 41.— Guayabota : Top, flatsawed ;bottom, quartersawed.

HIGÜERILLO

Vitex divaricata Sw. (verbena family, Verbenaceae)

Higüerillo, or white fiddlewood, is closely re-lated to teca and possesses many of the good fea-tures of that wood. The heartwood (fig. 42) istan to brown colored when freshly cut and gen-erally variegated with darker shades of tan orbrown. After seasoning and exposure, the heart-wood becomes gray brown to deep brown, oftenwith indistinct alternating narrow bands oflighter or darker wood. The fairly distinct sap-wood is grayish colored when green, turning alight. brown upon drying.

The wood has medium luster, fine texture, andfairly well defined growth layers. The grain isirregular and interlocked, making it unusuallystrong in resistance to splitting. Odor and tasteare not distinctive in seasoned wood. Higüerillois a heavy wood, weighing 47 pounds per cubicfoot air-dry and 72 pounds green.

Green lumber dries so slowly that it is imprac-tical to air-season the wood on a commercial scale.In the study, higüerillo was not completely air-dry after more than 1 year under cover in theSan Juan area. Degrade, which occurred duringthe 1-year seasoning period, was confined to asmall amount of warping; there was no apparentsurface checking, end splitting, or casehardening.

Higüerillo undergoes modelately low and uni-form shrinkage for a wood of its high density,being considerably better in this respect thanmany other woods of similar weight. Green woodshrinks at the rate of 3/16 inch (1.6 percent,) perfoot in width across the growth rings and 7/16inch (3.5 percent) per foot parallel to the growthrings in seasoning to 15 percent moisture content.Its longitudinal shrinkage of 0.21 percent is nomi-nal for a wood with interlocked grain.


Higüerillo saws and machines easily with fairlygood results. It is an excellent wood to turn butplanes poorly because of the tearing and roughnessthat develop in the numerous pieces having ir-regular grain. The wood gives good results inshaping, boring, and mortising, but fine abrasivesare necessary in sanding to obtain good results.It finishes satisfactorily and takes a high polishbut, judging by related species, it may be somewhatdifficult to glue.

The wood is moderately resistant to dry-woodtermites. Although specific information is lack-ing for higüerillo, closely related species are re-ported to have some resistance to marine borersand fair resistance to fungal attack. Higüerillois a strong, hard, tough wood, comparable to whiteoak in all strength properties.

A closely related species, Vitex gaumeri, of Brit-ish Honduras, has been used successfully for polo-stick heads because of its high resistsance tosplitting and denting. Higüerillo may be equallyuseful for this purpose and for other purposessuch as golf-club heads, croquet, mallets, othersporting goods, and, tool handles. It should alsobe suitable for boat decking and planking, floor-ing, and general construction. In Central Amer-ica, several other species of Vitex are used forheavy and durable construction. F–495349

FIGURE 42.— Higüerillo : Top, flatsawed ; bottom, quarter-sawed.

JÁ CANA

Pouteria multiflora (A. DC.) Eyma (sapodilla family, Sapotaceae)

The heartwood (fig. 43) of jácana is reddishbrown and not readily distinguished from the dull,light-brown sapwood. The wood has uniformlyfine texture, generally straight grain, and mediumto low luster. Growth rings are not evident, andodor and taste are absent in seasoned wood. It isvery hard, firm, strong, and very heavy, weighing59 pounds per cubic foot air-dry and 74 poundsgreen.

Jácana is a difficult wood to air-season; it driesslowly, with considerable degrade. About 7months is required to air-season the wood to 17percent moisture content under cover in the SanJuan area. Moderate cup, bow, twist and surfacechecking occur during the seasoning process, alongwith very slight crook and slight end checking.Surface checks and end splits are apt to be deepwhenever they occur and to widen and extend asdrying progresses. None of the defects is par-

5 9 6 0 3 3 O— 61— — –5

titularly serious individually, but in the aggregatethey cause a considerable loss during seasoning.

High but uniform shrinkage occurs during sea-soning. Green wood loses 7/16 inch (3.6 percent)per foot in width across the growth rings and 2/3inch (5.4 percent) per foot along the growth ringsin drying to 15 percent moisture content.

The wood is fairly difficult to work because ofits high density, hardness, and silica. Yet, it. isconsidered a good working wood except in plan-ing. Considerable torn grain occurs. in this opera-tion when wavy or irregular grain is present andto some extent in straight-grained pieces. Be-cause of its high density and straight, even grain,the wood splits rather easily with screws or nailsbut should finish and glue satisfactorily.

Jácana is moderately resistant to dry-wood ter-mites and other insects, and it probably is slightlyto moderately resistant to decay when in contact


with the ground. Molds and sap-staining fungiare not troublesome in the log or during seasoning.

The difficulty in seasoning jácana, plus its com-mon appearance and only fair planing qualities, re-stricts its use to some extent. It is currently usedin other Caribbean areas for heavy constructionhouse framing, bridgework, posts, and other usesrequiring a heavy, hard, strong wood. It shouldalso be suitable for furniture, agricultural imple-ments, some types of sporting goods, heavy floor-ing, piling in nonteredo areas, and boat timbers.

F— 495350

FIGURE 48.— Jácana: Top, flatsawed ; bottom, quarter-sawed.

JAGUAGenipa americana L. (madder family, Rubiaceae)

Jagua, or genipa, is an attractive timber suit-able for many of the same uses as ash, maple, andbirch. The heartwood (fig. 44) is a very lightyellowish brown, occasionally with a slight pink-ish- or purplish-blue overcast, merging graduallyinto the cream-colored sapwood. Growth ringsare indistinctly marked by narrow bands of darkercolored wood which at times show on the quarter-sawed surface as faint lines, giving the wood anattractive striped figure. Flatsawed surfaces fre-quently have a ribbon stripe.

The wood has medium luster, rather fine textureand straight to irregular grain. Distinctive odorand taste are not apparent in seasoned wood. Thewood is hard, heavy, strong, and resilient, weigh-ing 51 pounds when air-dry and 64 pounds green.

Jagua air-seasons slowly, green 11/8-inch lumberrequiring 7 to 8 months to reach 20 percent mois-ture content. However, only a minor amountof warping occurs during seasoning, and virtuallyno surface checking.

The wood undergoes moderate and fairly uni-form shrinkage during seasoning and should stayin place well after manufacture. Green woodshrinks at the rate of about. 1/5 inch (1.7 percent)per foot in width across the growth rings and 1/2inch (4.1 percent) per foot parallel to the growthrings in drying to 15 percent moisture content.

Jagua works easily and with excellent, resultsmachining better than most other Puerto Ricanwoods, and ranking well above mahogany, teca,and other well-liked cabinetwoods. It has goodresistance to screw splitting, glues satisfactorily,


and should take all types of stains and finisheswithout difficulty. The heartwood is very sus-ceptible to pinhole borers, dry-wood termites, anddecay. Sap-staining fungi are seldom trouble-some during seasoning.

Jagua is used for shoe lasts, plow beams, toolhandles, barrel hoops, chests, and many otherproducts requiring fine and uniform texture com-bined with high strength and resilience. Thewood is especially good for all types of bent, workand should be a very satisfactory substitute forash. Its excellent machining qualities, attractive-ness, and uniform texture make it an excellentmaterial for furniture, cabinetwork, and turneryof all types. It should also work well as flooring,interior trim, and decorative veneer, and for mostpurposes for which maple, birch, or ash are cur-rently preferred.

F— 495351

FIGURE 44.— Jagua : Top, flatsawed ; bottom,quartersawed.

JAGÜEY BLANCO

Ficus laevigata Vahl (mulberry family, Moraceae)

This species is related to the common cultivatedfig, Ficus carica L., and the rubber plant of theflorists, F. elastica Roxb., from the Far East. Thetree and wood are known in Puerto Rico as jagüeyblanco. The English name is shortleaf fig. Thetree does not produce edible fruit.

Both the heartwood (fig. 45) and sapwood area uniform light brown. The wood is composed ofalternating bands of wood fibers and soft paren-chyma, which shows on the flatsawed surface asan irregular darker brown pattern and on the quar-tersawed surface as a very fine, closely spacedstriping. Surfaces having an appreciable amountof the soft, darker colored parenchyma tissue arecorrespondingly more difficult to machine.

The wood has low luster, coarse texture, andstraight grain. It is fairly light and soft, buttough and strong for its weight. Air-dry woodweighs 30 pounds per cubic foot and green woodabout 55 pounds.

The wood is heavily saturated with moisture(119 percent) when first cut. It seasons slowly,requiring 6 to 7 months to reach an air-dry mois-ture content of 17 percent in the San Juan area.However, very little degrade occurs and even thewidest boards dry with a minimum of distortion.Degrade is confined to slight’ bow and twist andvery slight cup and crook. Discoloration of thesapwood by fungi is common during the earlystages of seasoning, and it is difficult to controlunless the lumber is immersed or sprayed with afungicide solution immediately after sawing.

Shrinkage is low and fairly uniform during sea-soning. Green wood shrinks at the rate of 1/8 inch(1.0 percent ) per foot in width across the growthrings and 1/3 inch (2.8 percent) per foot along thegrowth rings in drying to 15 percent moisturecontent,.


F— 495352

FIGURE 45.— Jagüey blanco: Top, flatsawed ; bottom,quartersawed.

Jagüey blanco works easily but with poor re-sults, except in planing and sanding, in whichsatisfactory surfaces are obtained. The woodtends to pickup and fuzz in shaping and turningand to crush and crumble in boring and mortising.The preponderance of soft parenchyma tissue isresponsible for most of the machining difficulties.It is also responsible for all surfaces being some-what rough to the touch and requiring carefulsanding before polishing. Jagüey blanco has ex-cellent resistance to screw splitting, and it is re-ported to take and hold nails firmly and finishsmoothly with paint or varnish.

The wood is very susceptible to damage by ter-mites and other insects, decay-causing fungi, andprobably marine borers. But, judged by its ap-pearance and structure, jagüey blanco should beeasily impregnated with preservatives to combatthese destructive agencies.

The various Ficus woods are generally con-sidered to have limited commercial value on theexport, market, though they we suitable for manyeveryday purposes if seasoned before they can de-cay. Air-dry jagüey blanco can be used for boxes,crates, interior construction, general light, carpen-try, and temporary concrete forms. After properpreservative treatment, it would also be suitablefor numerous outdoor uses where a light, easilynailed, moderately strong wood is acceptable.

JOBO

Spondias mombin L. (cashew family, Anacardiaceae)

Jobo, or yellow mombin, is a soft, lightweightwood of common appearance (fig. 46). When first

Jobo is moderately easy to season. Green wood

cut, the heartwood is buff colored and indistin-11/8 inches thick air-dries to a moisture content of

guishable from the sapwood, but when seasoned itabout 16 percent in 6 months under cover in the

turns a golden brown and is readily distinguishedSan Juan area. Moderate degrade occurs during

from the cream-colored sapwood. Both heartwoodseasoning in the form of very slight cup, moderate

and sapwood are often turned to a blue-gray colorbow, slight twist and crook, and very slight end

by sap-staining fungi during the early stages ofand surface checking. Heavy mold occurs on both

seasoning. Jobo weighs about 30 pounds whensapwood and heartwood unless the wood is im-

air-dry and 60 pounds when green at 133 percentmersed in a fungicide soon after it is sawed.

moisture content.Low and uniform shrinkage occurs during the

The wood has straight to slightly interlockedseasoning process. Green wood shrinks at the

grain and coarse texture. Numerous pores, barelyrate of 1/10 inch (0.9 percent) per foot in width

visible on end surfaces, appear on the longitudinalacross the growth rings and 7/32 inch (1.8 percent)

surfaces as distinct grooves or as somewhat darkerper foot parallel to the growth rings in drying to

lines or scratches against the lighter background.a moisture content of 15 percent.

The wood possesses no characteristic odor or taste.The wood is easy to work but has rather poor

machining properties unless handled carefully.


It is an excellent wood to plane but develops roughand torn surfaces in other machining operationsthat use conventional hobby-shop size machinesand tools. However, the wood sands fairly welland has good resistance to screw splitting. Jobois very susceptible to decay, termites, and otherinsects; logs left in the woods are soon attackedby pinhole borers.

Jobo possesses moderate strength properties, be-ing somewhat harder on the end and sides thanmany woods of comparable density; in general,it is tough and strong for its weight. Jobo is usedfor soft-drink cases, packing boxes of all types,interior construction, and match splints. It hasbeen recommended for utility plywood. It willproduce a good yield of pulp that is suitable formaking a strong, white printing paper. Withspecial care in machining, the wood could alsobe utilized in the cheaper grades of furniture andcabinetwork, and it is quite suitable for light con-struction of all types when protected from insectsand decay. Because large cuttings take rootreadily, sections of young sterns and limbs of largetrees are used extensively for live fence posts.

F— 495353

FIGURE 46.— Jobo : Top, flatsawed ; bottom, quartersawed.

JUSILLO

Calycogonium squamulosum Cogn. (melastome family, Melastomataceae)

Jusillo, also commonly known as camasey negro,is one of several species of the genus Caly-cogonium that are endemic to Puerto Rico. Thepinkish-brown to pale-brown heartwood ischaracterized by irregular, widely spaced blackstreaks of varying widths, giving the wood anunusual and somewhat attractive appearance (fig.47). The sapwood is bright yellow and fairlywell distinguished from the heartwood. Thewood has fine texture, generally straight grain,and good lustre, and it is odorless and tastless andwithout distinctive growth rings. It is hard,heavy, and strong, weighing about 56 pounds percubic foot when air-dry and 76 pounds whengreen.

The wood seasons at a moderate rate with amoderate amount of degrade. Green lumber air-dries to about 18 percent moisture content in 6

months under cover in the San Juan area. De-grade is limited to a moderate amount of warp andsome very light surface and end checking. Asmall amount of casehardening may also occur attimes.

Shrinkage is moderate and uniform duringseasoning despite the wood’s high density. Fresh-ly sawed lumber shrinks ¼ inch (2.2 percent) perfoot across the growth rings and nearly ½ inch(3.9 percent) per foot along the growth rings inseasoning from the green condition to 15 percentmoisture content. Longitudinal shrinkage is alsomoderate.

The wood’s hardness and density make it mod-erately difficult to saw and machine, but it canbe worked to a glasslike surface in all operationsexcept planing. The frequent occurrence of torngrain makes this operation difficult. In sanding,the wood will show scratches unless a very fine

6 6 U.S. DEPT. OF AGRICULTURE HANDBOOK NO. 205

FIGURE 47.— Jusillo: Top, flatsawed : bottom,F–495354

quartersawed.

abrasive is used. Jusillo is also very susceptibleto splitting by nails or screws unless it is pre-bored or adequate-sized lead holes are employed.It should glue satisfactorily and finish exception-ally well with all types of coatings.

The heartwood is very susceptible to dry-woodtermites and of doubtful durability in contact,with the ground or in teredo-infested waters.Pinhole borers will also attack the wood beforeand after it is sawed.

The wood is considerably heavier, harder, andprobably stronger than sugar maple or yellowbirch. It is suitable for the same purposes asthese woods, except where the pinkish to pale-brown color or the unusual and characteristic pat-tern of black lines would be objectionable. Thefigure is of a type that might be quite acceptablefor some purposes and quite objectionable inothers.

Judged by its physical properties, the wood issuitable for furniture, patternmaking, veneer andplywood, agricultural implements, tool handles,heavy-duty flooring, turnery, boat parts, and vehi-cle frames. It would also give good service forheavy construction, bridge timbers, and piling innonteredo areas. After preservative treatment, itshould also serve well for railway ties, posts,poles, and other products that would be in contactwith the ground.

LAUREL AMARILLO

Nectandra sintenisii Mez (laurel family, Lauraceae)

Laurel amarillo is a rather light, moderatelysoft wood resembling yellow-poplar (Lirioden-dron tulipifera) of the United States in superficialappearance (fig. 48). The heartwood is a palegreenish yellow, merging gradually into a slightlylighter colored sapwood. The luster is satiny, thetexture medium, and the grain straight to mowfrequently interlocked. Odor and taste are notdistinctive in seasoned wood. Air-dry woodweighs about 41 pounds per cubic foot and greenwood 54 pounds per cubic foot.

The wood air-seasons satisfactorily without ex-cessive degrade. It air-dries at a moderate rate,reaching about 17 percent moisture content in 6 to7 months under cover in the San Juan area. Mod-erate degrade occurs during seasoning in the formof very slight cup, end checking, and crook, andslight twist and moderate bow.was not evident in the tests.

Surface checking

Laurel amarillo is easy to work and producesgood surfaces in all operations except planing,where the frequent roey grain causes considerabletorn and fuzzy surfaces. The species of Nectandra,as a group, are considered to glue and paint welland hold nails satisfactorily. Laurel amarillo isprobably similar to other members of the genusin these properties.

Low to moderate shrinkage occurs during sea-soning. Green wood of this species shrinks at therate of 1/8 inch (1.1 percent) per foot across thegrowth rings and ¼ inch (2.0 percent) per footalong the growth rings in drying to 15 percentmoisture content. The wood is extremely resist-ant to moisture absorption and holds its place ex-ceptionally well after manufacture.

Laurel amarillo is very susceptible to attack bydry-wood termites, marine borers, and sap-stainingfungi. Like other closely related species, it may


he moderately durable in the ground. The heart-wood is extremely resistant to impregnation withpreservatives, though the sapwood is easilytreated.

The wood is somewhat lighter than white oak,but tests of other species of the genus indicate thatit should be comparable to white oak in mostmechanical properties except resistance to split-ting, in which it is only 60 percent as strong as oak.It is a moderately good bending wood.

The wood of laurel amarillo is suitable for gen-eral construction, boxes, crates, carpentry, mill-work, flooring, and interior trim. Although it isnot particularly attractive, it should be suitablefor some types of furniture and cabinetwork; how-ever, the wood’s poor planing qualities wouldnecessitate considerable sanding of exposed sur-faces prior to finishing. Other similar species ofNectandra have been recommended for tool han-dles, instruments, crossties, and boat construction.

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FIGURE 48.— Laurel amarillo; Top, flatsawed, bottom,quartersawed.

LAUREL AVISPILLO

Nectandra coriacea (Sw.) Griseb. (laurel family, Lauraceae)

Laurel avispillo, or Jamaica necandra, haspinkish-colored heartwood (fig. 49), which mergesgradually into light-brown sapwood. The woodappears to have zones of tension wood composed ofsoft gelatinous fibers that are similar to those oc-curring in Mexican mahogany; they appear asslightly darker colored bands or stripes on flat-sawed surfaces. These areas give the wood anattractive configuration but present trouble inmost machining operations because they developconsiderable fuzziness.

The plain is straight to irregular and tightlyinterlocked, the texture is medium, and the lusteris medium to high. The wood is moderately softand light, weighing 36 pounds air-dry and 51pounds green per cubic foot.

The wood air-seasons easily and satisfactorilyexcept for a moderate amount of warping. Sur-face and end checking are not troublesome. Greenlumber air-seasons to about 17 percent moisturecontent in 6 months under cover in the San Juanarea. Shrinkage is moderate and uniform duringseasoning. Green wood shrinks 1/6 inch (1.4 per-cent) per foot across the growth rings and 4/10 inch(3.3 percent) per foot parallel to the growth ringsin drying to a moisture content of 15 percent. Allspecies of Nectandra are reported to be stableafter manufacture.

The wood is easily machined with good resultsin all operations except turning and sanding.Torn and fuzzy grain develop in turning andsevere fuzzing during sanding wherever there is a


F— 495356

FIGURE 49.— Laurel avispillo : Top, flatsawed ; bottom,quartersawed.quartersawed.

tension-wood zone. However, with extra care thewood can be finished to a very smooth, paintablesurface and when properly sanded is equal orsuperior to Mexican mahogany in attractiveness.Laurel avispillo takes and holds screws and nailssatisfactorily, glues well, and can be painted orvarnished with good results. Grain fillers are notrequired as in laurel prieto.

The heartwood of laurel avispillo is very suscep-tible to dry-wood termites and other insects, andthe logs are readily attacked by pinhole borers.Both logs and green lumber are fairly resistantto sap-staining fungi. The heartwood of otherspecies of Nectandra is moderately durable in theground but is very resistant to impregnation withpreservatives while the sapwood is not durable andis easily treated. Laurel avispillo may have simi-lar characteristics in these respects.

The wood is suitable, with considerable care inmachining, for furniture, cabinetwork, interiortrim, paneling, toys, novelties, turning, and otheruses requiring an attractive wood of moderatestrength and durability. It is also well qualifiedfor general carpentry, interior and exterior con-struction, and possibly for decorative veneer andplywood. The wood is also satisfactory for boxes,crates, toys, boatbuilding, and other miscellaneoususes.

LAUREL GEO

Ocotea leucoxylon (Sw.) Maza (laurel family, Lauraceae)

Laurel geo is a moderately soft, light wood.The heartwood (fig. 50) is uniform light goldenbrown with medium luster, and generally it isnot sharply delineated from the pale yellowish-brown or cream-colored sapwood. The wood hasmedium texture, straight to more frequently inter-locked grain, and lacks distinctive odor or tastewhen seasoned. The lack of figure and the wood’sdull-brown color give it a rather common ap-pearance. Air-dry wood weighs 34 pounds percubic foot and green wood 50 pounds per cubicfoot.

Laurel geo is difficult to air-season. The wooddries at a moderate rate, reaching an air-drymoisture content of 16 percent in about 5 monthsunder cover in the San Juan area. There is severedegrade during air-seasoning in the form of cup,bow, twist, and crook, but no appreciable end OKsurface checking.

Moderate and uniform shrinkage occurs duringair-drying. Green wood shrinks 5/32 inch (1.2percent) per foot in width across the growth ringsand 1/6 inch (2.4 percent) per foot along thegrowth rings in drying to an air-dry moisturecontent of 15 percent. As judged from tests ofother species of Ocotea, laurel geo should be stableafter manufacture and should withstand exposurewell without the protection of paint.

Laurel geo saws and machines easily with littledulling effect, on cutting edges. Machined sur-faces are acceptably smooth, except for a tendencytoward fuzziness in sanding and frequent crushingand tearing of the wood in boring. Other similarspecies of Ocotea are known to take good finishwith paint, stain, or varnish, to glue well, and tohold nails satisfactorily except on the end grain.


The wood is moderately resistant, to dry-woodtermites, and observation of closely related speciesindicates that it may be moderately resistant todecay. The heartwood of other species is highlyresistant to impregnation with preservatives whilethe sapwood is easily treated. Sap-staining fungiare troublesome in freshly cut logs and lumber, andpinhole borers often attack logs soon after felling.

Laurel geo is suitable for inexpensive grades offurniture and cabinetwork and for interior trim,general capentry, and light interior and exteriorconstruction. It may be one of the better localwoods for boxes and crates, plywood, sheathing,concrete forms, and other products where amoderately light, easily worked, yet moderatelystrong wood is required. It does not possess suf-ficient attractiveness for decorative purposes tocompete with a number of other local woods.

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FIGURE 50.— Laurel geo: Top. flatsawed; bottom,quartersawed.

LAUREL PRIETO

Nectandra membranacea (Sw.) Griseb. (laurel family, Lauraceae)

Laurel prieto logs are generally small indiameter but of good quality. The heartwood isyellowish brown to golden brown in contrast to thefairly distinct grayish-colored sapwood. Thewood lacks attractive figure except for the pres-ence of faint ribbonlike stripes (fig. 51) in thosepieces having fairly distinct growth rings. Openpores on the end grain appear as elongatedscratches on flatsawed surfaces, giving the wooda somewhat rough texture. The wood has straightto occasionally wavy grain, medium texture, andmedium luster. Air-dry wood weighs 34 poundsper cubic foot and green wood 46 pounds per cubicfoot.

This timber air-seasons at a moderate rate andsatisfactorily, reaching an air-dry moisture con-tent of about 16 percent in 6 months under cover

in the San Juan area. A minor amount of de-grade occurs in the form of slight bow and veryslight cup, twist, and crook. Surface checkingand casehardening are not a problem.

Shrinkage is moderate and uniform duringseasoning, amounting to 5/32 inch (1.3 percent) perfoot in width across the growth rings and 12/32inch (3.0 percent) per foot parallel to the growthrings from green to an air-dry moisture contentof 15 percent. Seasoned wood holds its place wellafter manufacture.

Laurel prieto saws and machines easily, but ithas a tendency to tear and develop fuzziness dur-ing sawing. Good results are obtained in planing,shaping, and mortising; torn grain is quite trouble-some in turning and boring; and fine scratches areevident in sanding. If fine abrasives are used, the


wood can be finished to a smooth, uniformsurf ace. The wood takes all types of finishes satis-factorily after its characteristic open grain hasbeen properly filled. It should nail and glue with-out difficulty.

The heartwood of laurel prieto is consideredvery susceptible to dry-wood termites and maybe vulnerable to decay-causing organisms. Logsand lumber are both subject to sap-staining fungi.The heartwood of other species of Nectandra isreported to be very resistant to impregnation withpreservatives. This species may be similarly re-sistant.

Laurel prieto’s wood is moderately soft andlight but, if similar to other closely related species,should possess good strength properties. It lacksattractiveness and good working properties foruse in furniture and cabinetwork, but it is suita-ble for boxes, crates, interior trim, and possiblyplywood. The wood is sufficiently strong for gen-eral carpentry and light construction of all types,particularly for studding, sheathing, wall parti-tions, and similar uses.

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FIGURE 51.— Laurel prieto : Top, flatsawed ; bottom,quartersawed.

LAUREL SABINO

Magnolia splendens Urban (magnolia family, Magnoliaceae)

Laurel sabino is limited to Puerto Rico, whereit, is one of the most highly regarded woods forfurniture and cabinetwork Short logs of mediumto frequently large diameter are obtained fromthe very old crooked-growing trees found scat-tered in the high rain forests of the easternmountains.

Freshly cut heartwood (fig. 52) is an unusualand very attractive olive green, turning mediumto dark brown upon seasoning and exposure.Growth rings are marked by fairly distinct linesof lighter colored wood which appear on thequartersawed surfaces as longitudinal stripes andon flatsawed surfaces as wavy lines, giving thewood a very attractive figure. Frequent darkstreaks give the wood additional figuration. Thesapwood is whitish when freshly cut, becomingsomewhat darker upon seasoning and exposure.

The grain is straight to more frequently wavy,texture is fine and uniform, and odor and taste arenot evident. The wood is moderately heavy,weighing 44 pounds per cubic foot air-dry and72 pounds green.

This wood is easy to air-season, drying rapidlywith only minor degrade in the form of veryslight bow and slight twist. Other forms of warpand surface checking were not apparent in thePuerto Rican tests. Green lumber 11/8 inchesthick air-seasons to about 17 percent moisturecontent in 3 to 4 months under cover in the SanJuan area.

Shrinkage is moderate in all directions andsomewhat below that of other woods of similardensity. Green wood shrinks at the rate of 3/16inch (1.5 percent) per foot in width across the


growth rings and 5/16 inch (2.6 percent.) per footalong the growth rings in drying to 15 percentmoisture content. Molds and sap-staining fungiseldom develop during seasoning. The wood staysin place well after manufacture.

Laurel sabino saws and machines easily. However, in planning, considerable tearing occurs asa result of the irregular grain. In the PuertoRican tests, the wood gave fair results in planing;good results in shaping, turning, boring, mortis-ing, and screw splitting; and fair results in send-ing. A fine abrasive paper should be used to over-come scratching. The wood is moderately resistantto dry-wood termites but very susceptible to decaywhen in contact with the ground.

Laurel sabino is moderately strong, comparingfavorably with other woods of similar density.It is used extensively in Puerto Rico for furni-ture and cabinetwork. The wood has a numberof desirable qualities and should he suitable forutility and decorative veneer and plywood, mill-work, turnings of many types, durable construc-tion, boat planking, and general interior and ex-terior construction and carpentry. Unfortu-nately, the exceptionally attractive brightolive-green color in freshly worked wood disap-pears through an oxidation process that leavesthe wood a pleasing but less attractive brown. F— 495359

FIGURE 52.— Laurel sabino : Top, flatsawed; bottom;quartersawed.

MAGO

Hernandia sonora L. (hernandia family, Hernandiaceae)

Mago is a film, soft, lightweight wood resem-bling the heavist grades of guano (balsa). Theheartwood (fig. 53) and sapwood are indistin-guishable, both grayish white in color withoccasional faint olive-colored streaks. Numerouslarge darker colored pores are visible on the endgrain and appear on longitudinal surfaces asnumerous brown dots or scratches, giving thewood a characteristic but not particularly attrac-tive appearance. The wood has low luster,medium to coarse texture, and straight grain.Air-dry wood weighs about 21 pounds per cubicfoot and green wood 35 pounds per cubic footas compared with 9 to 12 pounds for the com-mercial grade of air-dry guano.

The wood air-seasons satisfactorily. It driesat a rapid rate with only minor degrade in theform of very slight cup and crook, slight bow andtwist, and without any apparent surface or end

checking. Green 11/8-inch lumber air-seasons toabout 17 percent moisture content in slightly over4 months under cover in the San Juan area.

Shrinkage is moderate and uniform. Greenwood shrinks 1/16 inch (1.4 percent) per foot inwidth across the growth rings and 9/32 inch (2.4percent) per foot parallel to the growth ringsin drying to an air-dry moisture content of 15percent.

Mago works easily with either hand or powertools but develops fuzziness in most operationsand is reported to dull saw and knives ratherquickly. ‘The use of very sharp and thin cuttingedges is recommended. Mago is rated poor tovery poor in all machining qualities but, becauseof its softness and straight grain, takes both nailsand screws without splitting. Finishing andpolishing is difficult; this is due to the soft, porousnature of the wood.


Mago is very susceptible to termites and otherinsects, marine borers, and decay-producingorganisms. It probably is penetrated readily bypreservatives and could be made acceptable formany uses by preservative treatment.

Because of its light weight, softness, and lowstrength properties, mago is restricted to suchuses as light boxes, crates, fishing floats, temporaryboarding, and interior construction. It has beenrecommended for utility plywood and could beused as a substitute for the heavier grades ofguano (balsa). The wood is also used in BritishGuiana for flooring and native canoes in additionto most of the above uses.

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FIGURE 53.— Mago : Top, flatsawed ; bottom, quartersawed.

MAMEY

Mammea americana L. (mangosteen family, Guttiferae)

Mamey wood is obtained from trees betterknown for their fruit, the mammee apple, thanfor their wood. The wood is not plentiful andis very difficult to season, but it, is quite attractiveand works very well.

Seasoned heartwood (fig. 54) is a reddishbrown, merging gradually into the dull, slightlylighter colored sapwood. The surface of bothheartwood and sapwood are often flecked withsmall dark-colored oily exudations. The grainis straight to more frequently irregular and inter-locked, and the texture and luster are medium.Odor and taste are not distinctive in seasonedwood. Mamey wood is hard, heavy, and strong,weighing 54 pounds per cubic foot air-dry and71 pounds green.

The wood is difficult to season, requiring about5 months to air-dry to 22 percent moisture content

and undergoing considerable degrade during theprocess. Severe cup, twist, and surface checking,and moderate bow, crook, and end checkingdevelop during seasoning. Moderate to severecollapse and casehardening were also noted in thePuerto Rican study in which at least 50 percentof the volume was lost through seasoning defects.

Mamey undergoes exceptionally high shrink-age during seasoning and is quite unstable aftermanufacture. Green wood shrinks 2/3 inch (5.4percent) per foot in width across the growth ringsand nearly 11/2 inches (12.1 percent) per footparallel to the growth rings in drying to 15 per-cent moisture content. A longitudinal shrinkageof 0.38 percent is also high for the wood’s density,usually indicating unfavorable seasoning charac-teristics.


Mamey is moderately easy to saw and machineand produces satisfactory results in most opera-tions. The wood gives some trouble in sanding,because of the small scratches that occur whenordinary sanding belts are used. A sanding gritof 4/0 grade or finer is required to obtain scratch-free surfaces. The numerous small “resin” ductsmay also cause trouble when certain types offinishes are desired. For a wood of its density,mamey is unusually resistant to splitting by screwsor nails. It is very susceptible to damage by dry-wood termites but is moderately durable in theground.

Because of its poor seasoning characteristics,heavy shrinkage, and lack of stability after manu-facture, mamey is not suitable for furniture andsimilar uses. It is used principally for fenceposts, fuel, and miscellaneous domestic purposes.But it may be useful for turning and novelty itemsin which its attractive and somewhat unusual ap-pearance would be of value. The wood could alsobe utilized for some types of general constructionand carpentry.

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sawed.FIGURE 54.— Mamey: Top, flatsawed; bottom, quarter-

MANGO

Mangifera indica L. (cashew family, Anacardiaceae)

The mango tree is better known for its savoryfruit than for its wood, which is moderately at-tractive but quite difficult to work.

Seasoned heartwood (fig. 55) is a pale yellowishcolor and not clearly distinct from the cream-colored sapwood. The wood is characterized bynumerous large open pores, which are readilyvisible on the end grain and show as straight tofrequently wavy light-brown scratches on the lon-gitudinal surfaces, giving the wood a somewhatstippled appearance. Growth rings are fairlywell marked by narrow bands of darker coloredwood. The wood is lustrous, medium in texture,

has straight to wavy grain, and is without pro-nounced odor or taste after seasoning. Air-drywood weighs 41 pounds per cubic foot and greenwood about 59 pounds per cubic foot.

Mango is fairly easy to air-dry. The woodseasons at a moderate rate with only minor de-grade, drying to below 19 percent moisture con-tent in about 5 months under cover in the SanJuan area. Green 11/8-inch lumber air-dries with-out any appreciable surface checking and only aminor amount of warping. Discoloration fromsap-seasoning fungi is not apt to occur when lumberis stacked soon after sawing.


The wood undergoes fairly low and uniformshrinkage. Green wood loses 1/10 inch (0.8 per-cent) per foot in width across the growth ringsand 9/32 inch (2.3 percent) per foot parallel to thegrowth rings in seasoning to 15 percent moisturecontent.

-

Mango works easily but with only fair results.Torn grain and fuzziness are common in planing,shaping, and turning. In sanding there is a tend-ency for scratches to show unless very fined abra-sives are used. Only occasional roughness andtorn grain develop in boring and mortising.

The wood is moderately resistant to dry-woodtermites. It probably is rather low in resistanceto decay and to attack by marine borers.

Mango lacks the attractiveness and workabilityfor furniture and similar products, but it appearsto be well adapted for most types of constructionand other uses where a moderately heavy, strongwood of low to moderate durability and fairmachining quality is acceptable.

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FIGURE 55.— Mango : Top, flatsawed ; bottom, quarter-sawed.

MARÍA (SANTA MARÍA)

Calophyllum brasiliense Camb. (mangosteen family, Guttiferae)

This wood is known in Puerto Rico as bothmaría and santa maría. The heartwood (fig. 56)is variable in color, ranging from light pinkish toreddish brown, often with fine darker coloredstriping. The sapwood is light brown, usuallydistinct, from the heartwood. The grain may bestraight, but it is more frequently interlocked, thelatter type producing an attractive ribbon figureon the quartersawed surface. The luster ismedium and the texture moderately coarse. Thewood is without distinctive odor and taste.Growth rings are not evident to the naked eye.María is sometimes mistaken for Honduras ma-hogany, being somewhat similar in color and oftenshowing good figure. It is heavier and strongerthan mahogany and is more durable for some uses.Air-dry wood weighs 43 pounds per cubic footand green wood 66 pounds at 92 percent moisturecontent.

Maria is very difficult to air-season. Greenlumber 11/8 inches thick requires 6 months or moreto reach 18 percent moisture content in the SanJuan area. Seasoning is accompanied by severebow, twist, and crook, a moderate amount of cup,and slight end checking. Although end checksand splits are extended during seasoning, surfacechecking was not evident in the Puerto Ricanstudy. Except for a tendency for moisture to re-main in the center of heavy planks, quartersawedmaterial is reported to kiln-dry satisfactorilywhen low-temperature/high-humidity kiln sched-ules are used.

Maria undergoes above-average shrinkage fora wood of its density but stays in place well aftermanufacture. Green wood loses 3/8 inch (3.0 per-cent) per foot in width across the growth ringsand 9/16 inch (4.6 percent,) per foot along thegrowth rings in seasoning to 15 percent moisture


content. A longitudinal shrinkage of 0.03 per-cent is low for a wood having interlocked grain.

In the green condition, maría is stronger thanwhile oak in most strength properties and equal orsuperior to most other woods of similar density.When air-dry, the wood is comparable to the ap-preciably heavier white oak in all strength prop-erties except modulus of rupture, crushingstrength, hardness, and cleavage. Except for aslight deficiency in strength parallel to the grain,maría possesses average or better strength prop-erties for tropical woods in its density class.

The wood is fairly easy to work and, exceptfor occasional dark-streaked material that con-tains deposits of calcium carbonate, has little dull-ing effect on cutting edges. The machined sur-faces are generally good in shaping, mortising, andsanding but rather rough in boring and turning.Chipping and tearing is fairly common on sur-faces with interlocked grain, especially in planingand shaping. Cutting edges of 20° or less havebeen recommended to reduce such tearing to aminimum. Crushed and torn surfaces are alsofairly common in boring. María has good resist-ance to screw splitting. It glues, stains, andfinishes satisfactorily, requiring about the sameamount of filler as Mexican mahogany.

The heartwood is very susceptible to attackby marine borers and dry-wood termites, but ithas been reported moderately resistant to subter-ranean termites. Generally, it is moderately dur-able in contact with the ground. The sapwoodis easily impregnated with preservatives by eitherpressure or open-tank bath methods, but the heart-wood is extremely resistant under pressures up to140 pounds per square inch.

María is as attractive as Mexican mahogany andcan be used for many of the same purposes, but itis considerably more difficult to season and work.It is used for furniture, cabinetmaking, flooring,shingles, interior construction, shipbuilding, houseframing, agricultural implements, handles, and

F— 495363

FIGURE 56.--María : Top, flatsawed: bottom,quartersawed.

many other purposes where a fairly strong,moderately durable wood is required. It givesfair service as railway ties and other products thatmust contact the soil. The wood makes an attrac-tive veneer, but it is seldom used for this productbecause it tends to flake during the cuttingoperation.

MARICAO

Byrsonima coriaceum (Sw.) DC. (malpighia family, Malpighiaceae)

Maricao is a moderately hard, heavy wood, re- odor and taste are not evident in seasoned wood.sembling redgum (Liquidambar styraciflua) ofthe United States in appearance and physical

Air-dry wood weighs 48 pounds per cubic foot andgreen wood 67 pounds per cubic foot.

properties. The heartwood (fig. 57) is reddish The wood air-seasons fairly well, drying at abrown with a purplish cast and is generallymarked by darker colored stripes, which impart a

moderate rate with moderate degrade : very slight

stippled effect on the lighter colored background.cup, moderate bow, and slight crook and twist.End and surface checking are minor. Green

The gray to reddish-brown sapwood is distinct, lumber air-seasons to 16 percent in approximatelyfrom the heartwood. The luster is medium, the 6 months under cover in the San Juan area.grain straight to slightly roey, and the texture Shrinkage is moderate for the wood’s density.fine. Growth rings are not distinct. Distinctive Green wood shrinks at the rate of 1/16 inch (1.5


percent) per foot across the growth rings and 7/16inch (3.5 percent,) per foot along the growth ringsin seasoning to 15 percent, moisture content.

Maricao works fairly easily with both hand andpower tools. Good to excellent surfaces are pro-duced in all operations. Proper size lead holesmust be prebored before screws are driven or thewood splits rather badly. The wood requiressome filling before finishing.

Maricao is very susceptible to dry-wood ter-mites and other wood-destroying insects, onlyslightly resistant to decay, and fairly immune tosap-staining fungi. However, it seems to be moreimmune than most other local woods to pinholeborers. The wood is not regarded as having anyappreciable resistance to marine borers.

Both the heartwood and sapwood of Maricaoare recommended for fancy furniture and cabinet-work, turning, flooring, interior trim, and otherdecorative uses. The wood is also suitable forgeneral carpentry, house framing, and heavy con-struction. It has been recommended for plywoodand veneer.

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FIGURE 57.— Maricao : Top, flatsawed ; bottom, quarter-sawed.

MASA

Tetragastris balsamifera (Sw.) Kuntze (bursera family, Burseraceae)

Masa is a high-quality wood resembling yellowbirch of the United States, and it is suitable forthe same uses. The heartwood (fig. 58) is a lightreddish brown when first cut, becoming orangebrown upon seasoning and exposure. The sap-wood is sharply demarcated, white when first cutand later becoming a yellowish brown upon dry-ing and exposure. The grain is irregular to veryroey, luster medium, texture uniformly fine, andgrowth layers indistinct. Seasoned wood ismildly fragrant but has no distinctive taste. Thewood is quite heavy, weighing about 48 pounds percubic foot air-dry and 60 pounds green.

Masa is very easy to air-season, losing its mois-ture rapidly with only a very minor amount ofdegrade. Green lumber 11/8 inches thick seasonsto about 17 percent moisture content in less than4 months under cover in the San Juan area. De-grade occurring during seasoning is limited to

very slight bow and twist. Other forms of warp,surface checking, and interior defects did not de-velop in the Puerto Rican tests.

Masa undergoes moderate shrinkage for awood of its density and should be reasonably stablein use. Green wood shrinks at the rate of 1/4 inch(2.1 percent) per foot in width across the growthrings and 2/5 inch (3.4 percent) per foot along thegrowth rings in seasoning to 15 percent moisturecontent.

The wood is moderately easy to saw and ma-chine, producing clean, smooth surfaces in allonerations except planing, in which considerabletearing develops in pieces having roey grain.Masa takes both nails and screws poorly unless itis properly prebored; it sands to a smooth surface.and it is reported to polish very well with all typesof finishes.

The heartwood is very susceptible to damageby dry-wood termites and marine borers, but it

PUERTO RICAN WOODS

is generally durable to very durable in contactwith the ground. The lumber is seldom dis-colored by mold during seasoning.

Masa is a hard, compact, tough wood withstrength properties commensurate with its highdensity. It exceeds strong woods like yellow birchand shagbark hickory (Carya ovata) in moststrength properties, and it is exceptionally strongin resistance to splitting.

77

The wood has no distinctive figure, but it finishesmuch like sugar maple and yellow birch and issuitable for many of the same uses as these verypopular woods. It is used for high-grade fur-niture, cabinetwork, paneling, interior construc-tion, and oars. Other recommended uses includemillwork, light and heavy construction of alltypes, house and factory flooring, and outdooruses where decay resistance is required.

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FIGURE 58.— Masa: Top, flatsawed: bottom, quarter-sawed.

MOCA (ANGELIN)

Andira inermis (W. Wright) H.B.K. (legume family, Leguminosae)

Moca is a hard, heavy, coarse-textured woodthat resembles palm or pitch pine (Pinus rigida)in superficial appearance. Other names for thetree and wood are angelin and cabbage angelin.The heartwood (fig. 59) is yellowish brown todark reddish brown and clearly delineated fromthe pale-brown to grayish-yellow sapwood. Softlighter colored tissue appears on the end grain aswavy bands and on flatsawed surfaces as feather-like wavy hands of light-colored tissue. Thesealternate bands of dark and light fibers give thewood its unusual and decorative appearance, Thegrain is straight to slightly irregular, and theluster is rather low. Air-dry wood weighs about47 pounds per cubic foot and green wood 74pounds per cubic foot.

Moca air-seasons at a moderate rate withoutserious degrade. Most seasoning defects occur as

596033 O–61— — 6

very straight cup and a moderate amounts of bow.Other types of seasoning defects are slight. Greenlumber 11/8 inches thick air-seasons to about 17percent in 5 months under cover in the San Juanarea.

Moca undergoes low to moderate shrinkageduring seasoning and is moderately stable aftermanufacture. Green wood shrinks about, 1/6 inch(1.2 percent) per foot in width across the growthrings and 1/3 inch (2.5 percent) per foot alongthe growth rings in seasoning to an air-drymoisture content of 15 percent.

The wood works easily with both hand andmachine tools. Good to excellent surfaces areobtained in all operations except shaping, in whichraised and torn grain are common because of thebands of soft parenchyma tissue. A fine, ridgyappearance— raised grain— is also likely to occurin planing when dull knives are used. The wood


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FIGURE 59.— Moca : Top, flatsawed; bottom, quarter-sawed.

takes nails well, glues satisfactorily, and finisheswell, but lacks luster. Moca compares favorablywith woods of similar weight in most strengthproperties except for a tendency to be somewhatfissile. Some difficulty is encountered in Frenchpolishing, because the soft tissue absorbs polishmuch more readily than the hard tissue.

The sapwood parts of logs and freshly cut lum-ber are highly susceptible to discoloration by sap-staining fungi. The wood is moderately resistantto attack by dry-wood termites and is durable incontact with the ground. It is also moderatelyresistant to marine borers but contains no appreci-able amount of silica, which is often associatedwith resistance to this marine animal.

Moca’s high figure and attractive colorationcauses it to be used extensively for high-gradefurniture and cabinetwork and for many fancyturned articles, such as billiard-cue butts umbrellahandles, walking sticks, and police truncheons.The wood has virtually no resonance, making itparticularly suitable for radio and television cabi-nets. It is also utilized in the Caribbean area forheavy construction, bridge timbers, house framingand sheathing. Its good resistance to decay anddry-wood termites should make it useful for polesposts, and other similar uses where durability is’important.

MOTILLO

Sloanea berteriana Choisy (elaeocarpus family, Elaeocarpaceae)

Motillo (fig. 60) is a very hard, heavy, strongmulticolored wood. The heartwood may be gray-ish, grayish yellow brown, yellowish brown, or auniform pinkish brown to chocolate brown.Heartwood is usually distinct from the yellowish:colored sapwood. Indistinct darker brown stripesoccur at irregular intervals in some specimens

The mood has medium texture, low luster, ir-regular grain and it is without distinctive odoror taste. It is not particularly attractive andwould be difficult to use for furniture because ofits many colors. However, the wood of a uniformbrown color would be suitable for many decorativepurposes. dir-dry wood weighs 61 pounds percubic foot and green wood 75 pounds per cubicfoot at 51 percent moisture content.

The wood air-seasons moderately well dryingat a moderate rate with a moderate amount ofdegrade. Green lumber 11/8 inches thick air-

seasons to 16 percent moisture content, in 4 to 5months under cover in the San Juan area. Aslight to moderate amount of warp and surfacechecking occurs during the seasoning process.Shrinkage is moderate and uniform during season-ing. Green wood shrinks about 3/10 inch (2.4percent) per foot across the growth rings and 9/16inch (4.5 percent) per foot along the growth ringsin seasoning to 15 percent moisture content.

Motillo works fairly well and produce; goodto excellent surfaces in all machining operations.But it takes screws and nails poorly, requiringlead holes when screws are used and preboringbefore nailing.

The wood is moderately resistant to dry-woodtermites, rating slightly below Honduras ma-hogany in this respect. It is probably not, durablein the ground nor resistant to marine borers, al-though definite information is lacking.


While the wood lacks the attractiveness for fur-niture and cabinetwork, it is sufficiently hard,heavy, and strong for all types of heavy construc-tion, farm implement parts, handles, heavy-dutyflooring, boat parts, and piling in areas free ofthe wood-eating teredos.

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FIGURE 60.— Motillo : Top, flatsawed: bottom,quartersawed.

NIGRA LORA

Matayba domingensis (DC.) Radlk. (soapberry family, Sapindaceae)

Negra lora is an attractive, very hard, strongwood. The heartwood (fig. 61) is a uniform pink-ish brown and not easily distinguished from thelighter colored sapwood. The wood is fine-tex-tured and moderately lustrous. It has a distinc-tive foul odor. The grain is usually irregularand interlocked. Growth rings are not easily dis-tinguished. It is a heavy wood, weighing 54pounds per cubic foot air-dry and 72 pounds inthe green condition.

The wood seasons slowly but fairly well. Green11/8-inch lumber air-dries to 19 percent moisturecontent in about 7 months under cover in the SanJuan area. Slight cup, bow, and crook, and mod-erate twist, surface checking, and end defects de-velop during the slow seasoning process.

Shrinkage is uniform but greater than the aver-age for woods of similar density. Green woodshrinks 1/3 inch (2.7 percent) per foot in widthacross the growth rings and 9/16 inch (4.8 percent)per foot along the growth rings in seasoning tothe air-dry condition. Sap-staining fungi areseldom a problem in seasoning this wood.

Negra lora is moderately difficult to saw andmachine and has an appreciable dulling effect oncutting edges. Machined surfaces are of goodquality in all operations except planing, in whichthe irregular grain causes considerable coarse fuz-ziness and tearing. Despite its roey grain, negralora splits rather easily when screws are driven.It should glue well and take all stains and pol-ishes satisfactorily. The wood is very susceptible


to damage by dry-wood termintes and otherinsects.

Negra lora is well suited for furniture, cabinet-work, turnery, interior trim, flooring, and otherproducts which require an attractive wood thatworks well but that need not be durable. Thewood should also be useful for handles, agricul-tural implements, cartwrights work of all types,cart and vehicle bodies, and other uses where itshardness and strength are a consideration. Itwould also be suitable for both light and heavyconstruction of all types where durability is not,a factor and, after preservative treatment, forposts and poles.

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FIGURE 61.— Negra lora : Top, flatsawed ; bottom,quartersawed.

NEMOCÁ

Ocotea spathulata Mez (laurel family, Lauraceae)

Nemocá is characterized by an unusual arrayof coloration and figure and is easily the mostunusual and perhaps the most attractively figuredcommercial wood that grows in Puerto Rico (fig.62). Color of the heartwood may be light pinkishbrown, yellowish brown, or greenish brown, inter-spersed with areas of dark brown to black stripes,scratches, spots, or wavy irregular lines. Thisintermingling of darker and lighter areas is socomplete that. no two pieces of heartwood areexactly alike.

The clearly defined sapwood varies from a yel-lowish brown on the outer edge to a pinkish browntowards the interior; it. lacks the dark markingsand variegated characteristics of the heartwood.The wood has fine texture, medium luster, andgenerally interlocked grain. Growth rings are

not distinct. The wood has no odor or taste.Nemocá is hard, heavy, and strong, weighing 47pounds per cubic foot when air-dry and 62 poundsgreen.

The wood is moderately difficult to air-season.Green lumber air-seasons at a moderate rate,reaching 17 percent moisture content in 5 to 6months under cover in the San Juan area. Mod-erate degrade occurs during drying in the formof very slight cup and surface checking, slightto moderate twist, and moderate bow and crook.Degrade is more severe in the darkest coloredwood coming from the heart of the tree. Shrink-age, particularly for a wood of nemocá’s density,is moderate and fairly uniform. Green woodshrinks at the rate of 2/10 inch (1.8 percent) perfoot in width across the growth rings and 4/10inch (3.4 percent) per foot along the growth


rings in drying to 15 percent, moisture content.Nemocá is moderately difficult to work because

of its hardness and interlocked grain, but it givesgood to excellent results in all machining proper-ties except planing, in which there is consider-able pickup and tearing. The roey grain, whichis responsible for the diffculty in planing is,however, what gives the wood good resistance toscrew splitting. Nemocá can be sanded to a verysmooth surface; it will take all types of finishesand polishes satisfactorily.

Certain other species of Ocotea are highly re-sistant to insects and decay, but on the basis of re-cent tests nemocá is very susceptible to dry-woodtermites. Its durability in the ground and interedo-infested waters is unknown. Pinholeborers are not a serious problem in the logs, andsap-staining fungi are not troublesome duringseasoning.

The heartwood possesses the attractiveness,good working properties, and favorable technicalproperties for furniture, cabinetmaking, paneling,turnery, boat planking, farm implements, handles,heavy construction of all types, bridge building,and piling in nonteredo areas. The rather wideuniform-colored sapwood could he used for floor-ing, interior trim, millwork, and other productsfor which a light-colored uniform wood is pre-ferred. The heavily variegated wood shouldmake unusually attractive turnings and noveltyitems.

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FIGURE 62.— Nemocá : Top, flatsawed; bottom,quartersawed.

NUEZ MOSCADAOcotea moschata (Meisn.) Mez (laurel family, Lauraceae)

Nuez moscada logs are of medium to large size,good length, and exceptionally free from knotsand other defects. The wood (fig. 63) resemblesnemocá in general appearance and density. Theheartwood is extremely variable in color and figu-ration, ranging from a medium brown to darkbrown with irregular darker brown to blackstreaks or patches. The sapwood is yellowishto light brown and fairly distinct from the heart-wood. The unusual appearance of the heartwoodgives the wood an attractiveness that should makeit highly acceptable for certain decorativepurposes.

The wood has medium to fine texture, inter-locked grain, medium luster, and is without dis-tinctive odor or taste when dry. Growth ringsare distinct. Air-dry wood weighs about 44pounds per cubic foot and green wood 60 poundsper cubic foot.

Nuez moscada air-seasons satisfactorily. Green11/8-inch lumber dries rapidly under cover in theSan Juan area, reaching 18 percent moisture con-tent in about 4 months after piling. A smallamount of warping develops during seasoning,but no surface checking. The heavy, dark-coloredwood from the center of the tree appears to bemost susceptible to degrade.

Shrinkage is moderate and uniform duringseasoning, but after manufacture the wood tendsto twist not held securely in place. Greenwood shrinks at the rate of 7/32 inch (1.8 percent)per foot in width across the growth rings and3/8 inch (3.1 percent) per foot along the growthrings in seasoning to 15 percent moisture content.

Neuz moscada is moderately easy to saw andmachine, with good to excellent results in all opera-tions except planing, in which considerable pickupoccurs because of interlocked grain. It takes


screws and nails well without splitting, sands toa smooth, even surface, and can be painted orvarnished satisfactorily without the need offillers.

Dry-wood termites readily attack this wood,and it is presumably very susceptible to otherinsects, decay-causing fungi, and marine borers.Sap-staining fungi are not troublesome duringseasoning or in the logs.

Nuez moscada is recommended for turning,furniture, cabinetmaking, novelty items, and otheruses requiring an attractive wood that. has goodstrength and satisfactory working qualities. Itshould also be satisfactory for both light andheavy construction, bridge timbers, heavy crating,and packing boxes. The highly figured heart.-wood should be acceptable for interior trim, panel-ing, and similar products where an unusual andhighly figured wood is desired. Wood that isuniform in color may be useful for the same pur-poses and possibly for flooring.

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FIGURE 63.— Nuez moscada : Top, flatsawed ; bottom,quartersawed.

PALO COLORADO

Cyrilla racemiflora L. (cyrilla family, Cyrillaceae)

The huge, centuries-old palo Colorado trees ofthe upper mountain rain forests provide a limitedvolume of short but exceedingly large and gener-ally hollow logs. The hollow trees are favoritenesting places of the native Puerto Rican parrot.The wood is very attractive but develops exceed-ingly severe degrade during seasoning, whichlimits its utility as a commercial wood. The mostcommon English name for this wood is swampcyrilla.

Seasoned heartwood (fig. 64) is an attractivedark reddish brown, with the most deeply coloredspecimens being somewhat oily. The sapwood islighter brown and not clearly demarcated from theheartwood. The wood has fine and uniform tex-ture, heavily interlocked grain, and moderate tolow luster. Growth rings, which are formedannually, are distinct. Distinctive odor and tasteare lacking in seasoned wood. On the basis of

rough determinations, air-dry wood weighs about59 pounds per cubic foot and green wood 72pounds per cubic foot at 118 percent moisturecontent.

Palo Colorado seasons very slowly and under-goes exceptionally severe degrade. In the SanJuan area, green lumber 11/8 inches thick requires10 months or longer under cover to reach an air-dry moisture content of 19 percent. Even withslow seasoning, exceedingly severe warp, surfacechecking, end splitting, casehardening, collapse,and honey combing develop in each piece duringthe process. Degrade is so severe that air-drylumber is unfit for most commercial uses.

The wood also undergoes exceptionally highshrinkage during seasoning. Measurements madeon a large number of severely distorted samplesindicate that green lumber shrinks 6/10 inch (5.0percent) per foot in width across the annual rings


and 11/4 inches (10.3 percent) per foot in widthparallel to the annual rings in drying to 15 per-cent, moisture content. Its longitudinal shrinkageof 0.31 percent is also unusually high, even for awood with interlocked grain, which is an indica-tion of poor seasoning.

Palo colorado is relatively easy to saw andmachine unless severe casehardening or other in-ternal defects are present. Except for scratchesthat show in sanding unless fine abrasive paper isused, the wood gives good to excellent results inall machining properties. It is also very resistantto screw splitting, because of its fine and tightlyinterlocked grain. Machined surfaces are glossysmooth, and the darker pieces often have a some-what wavy or oily feel.

Palo colorado is very susceptible to dry-woodtermites and presumably other insects. It is con-sidered durable in the ground, although specificdata are lacking. Because of the wood’s extremelypoor seasoning characteristics and its heavy anduneven shrinkage, its most satisfactory use is inthe green condition, and then only in submergedplaces or other locations where drying will nottake place. This includes such uses as submergedor buried piling, underwater parts of docks andwharves, posts, and heavy construction on or be-neath the ground. However, if some satisfactoryseasoning method could be found, this specieswould be useful for many purposes requiring adecorative wood that has good machiningcharacteristics.

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FIGURE 64.— Palo colorado : Top, flatsawed ; bottom,quartersawed.

PALO DE HUESOHaenianthus salicifolius Griseb. (olive family, Oleaceae)

The heartwood is golden brown to chocolate

Palo de hueso (formerly known as Haenianthusobovatus Krug & Urban) belongs to a small genusof two or three species limited to the GreaterAntilles of the Caribbean area. It is an extremelyhard, heavy, strong wood, and somewhat bizarrein appearance (fig. 65).

brown, with wide alternate light and dark coloredstripes showing on quartersawed surfaces. Thesapwood is lighter in color and merges graduallyinto the heartwood. The wood has fine texture,fairly high luster, and usually interlocked grain.Growth rings are not distinct. Seasoned wood hasno characteristic odor or taste. Air-dry woodweighs 61 pounds per cubic foot and green woodabout 77 pounds per cubic foot at 52 percent mois-ture content.

The wood seasons at a moderate rate. Greenlumber air-dries to about 17 percent moisture con-tent in 6 months under cover in the San Juan area.

Very slight cup and crook, slight twist, and moder-ate bow occur during the air-seasoning process.A minor amount of surface and end checking alsodevelops.

Palo de hueso undergoes moderate and un-usually uniform shrinkage during seasoning fora wood of its density. The shrinkage of 1/4 inch(2.2 percent) per foot in width across the growthrings and 7/8 inch (3.5 percent) per foot in widthparallel to the growth rings in seasoning fromgreen to air-dry is considerably below the valuesfor many other commercial woods of similardensity. Its longitudinal shrinkage of 0.096 per-cent is also nominal for a wood having inter-locked grain.

Palo de hueso is rather difficult to work becauseof its density end hardness. Results in the differ-ent machining operations vary. The wood is dif-ficult to plane; frequent long, continuous stripsof tom fibers and coarse fuzziness develop in many


pieces. The presence of tension wood and itsgelatinous fibers, much like the condition foundin Honduras mahogany, accounts for the difficultyin planing. For the same reason, the wood givesonly fair results in shaping, but it is a good turn-ing wood, and produces excellent results in boringand mortising. It is a fairly good wood to sandand has fair resistance to screw splitting. Wher-ever defects are not present, the machined sur-faces are exceptionally smooth and can be sandedto a glass-like finish.

Dry-wood termites attack and destroy palo dehueso without difficulty, and pinhole borers attackthe sapwood of logs but are not apt to damage theheartwood. Neither logs nor freshly cut lumberare subject to discoloration by sap-staining fungi.Judging from closely related species, the woodprobably is fairly resistant to decay in the ground.

Palo de hueso is well suited for uses where anexceptionally heavy, strong, hard wood is required.It should be most suitable for turnings, noveltyitems, handles, machine parts, heavy construction,boat frames, heavy-duty flooring, work benches,bridge timbers, and pilingin nonteredo areas. Itis not particularly good for furniture and cabinet-work because of its heaviness, poor workingqualities, and rather unattractive appearance.

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FIGURE 65.— Palo de hueso : Top, flatsawed ; bottom,quartersawed.

PALO DE MATOS

Ormosia krugii Urban (legume family, Leguminosae)

Palo de matos is a medium-weight, somewhatcoarse-textured wood. The heartwood (fig. 66)is a uniform salmon color with occasional darkercolored streaks, and it is not distinct from theyellowish sapwood. Unfinished wood has moder-ate luster, and feels somewhat coarse or rough tothe touch. The wood has moderately coarse tex-ture, generally coarse and irregular grain, indis-tinct growth rings, and is without distinctive odorand taste. Large open pores that occur in rows,groups, and singly are visible to the naked eye onthe end grain. Air-dry wood weighs 37 poundsper cubic foot. and green wood 70 pounds at 124percent moisture content.

The wood air-seasoned slowly, requiring about6 months to reach an air-dry moisture content, of16 percent in the San Juan area. Seasoning isaccompanied by moderate degrade in the form of

moderate bow, slight cup and twist, and veryslight crook, surface checking, and end splittinDirectional shrinkage is moderate but relativelyuneven. Green wood shrinks at the rate of 1/8inch (1.1 percent) per foot in width across thegrowth rings and 3/8 inch (3.0 percent) per foot.parallel to the growth rings in seasoning to 15 per-cent moisture content.

Palo de matos saws and works easily in machin-ing operations, with fair to good results. Al-though the wood is rated good in planing, shaping,and sanding on the basis of smoothness of cut, themachined surfaces are somewhat rough and diffi-cult, to finish. It is only a fair wood to turn, bore,and mortise because of its tendency to tear andcrush in these operations. It has good resistanceto screw splitting and probably takes and holdsnails well. It finishes and polishes satisfactorily


but requires considerable sanding and the use ofa filter before application of varnish or otherfinishes.

The wood is very susceptible to damage by dry-wood termites, and it probably is also quite suscep-tible to decay and marine borers. Sap-stainingfungi are not particularly troublesome duringseasoning.

On the basis of limited tests of a closely relatedspecies growing in Brazil, palo de matos is con-sidered fairly strong, hard, and tough for its den-sity and may possess good bending properties.The Puerto Rican species is quite attractive afterfinishing and should be suitable for furniture, mill-work, interior and exterior construction, boxes,crates, concrete work, general carpentry, andpossibly for bent items and utility veneer.

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FIGURE 66.— Palo de matos: Top, flatsawed; bottom,quartersawed.

PANAPÉNArtocarpus altilis (Parkinson) Fosberg (mulberry family, Moraceae)

Panapén, or breadfruit, is a very soft, light-weight, wood, yet quite firm and strong for itsweight. The seasoned heartwood (fig. 67) isgolden colored, sometimes flecked with orange, andclearly distinguished from the light-yellow toyellowish-brown sapwood. Numerous large, openpores are visible on the end grain and show onthe side surfaces as closely spaced lines or scratches,giving the wood a coarse, uneven appearance. Al-though the wood’s luster is low, well-sanded sur-faces are fairly smooth, resembling oak in texture,and they are quite attractive because of theirpleasing golden color. The grain is irregular andat times interlocked. Growth rings are not ap-parent. There is no characteristic odor or taste.

Air-dry wood weighs 20 pounds per cubic foot.The amount of moisture in green wood increasesfrom the sapwood towards the center of the tree.

Material averaging 124 percent moisture contentin the Puerto Rican tests weighed 38 pounds percubic foot.

The high moisture content of the green woodmakes it moderately difficult to season. Freshlycut wood air-seasons at a moderate rate, reaching19 percent moisture content in 5 months undercover in the San Juan area. Well-seasoned ma-terial frequently contains pockets of moisture wellabove the moisture content of the surroundingwood. A moderate amount of warping occursduring air-drying, but no noticeable surface orend checking. Shrinkage is moderate and some-what uneven. Green wood shrinks at the rate of1/8 inch (1.0 percent,) per foot in width across thegrain and 1/3 inch (2.7 percent) per foot parallelto the grain in drying to 15 percent moisturecontent.


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FIGURE 67.— Panapén : Top, flatsawed ; bottom, quarter-sawed.

Panapén works easily with either power or handtools, but with generally poor results. Sawed

surfaces are inclined to be fuzzy, particularly inripping, although seasoned wood saws more easilyand with less fuzziness than green wood. In thePuerto Rican tests, panapén gave only fair re-sults in planing, because of frequent torn grainand fuzzy surfaces; poor results in sanding be-cause of the visible scratches and fuzziness thatoccur; and very poor results in shaping, turning,boring, and mortising because of the extreme easewith which the wood crushes, tears, and fuzzes inthese operations. However, with special care andusing thin cutting edges and reduced spindlespeed, the wood should work satisfactorily. Mois-ture pockets probably are responsible for some ofthe machining defects.

Panapén’s resistance to attack by dry-woodtermites is very low. It probably is also very sus-ceptible to decay and to attack by marine borers.Logs should be removed from the-forest soon afterfelling to avoid damage by pinhole borers and sap-stain. Fungi will also quickly discolor the sap-wood of lumber unless it is either surface-driedimmediately after sawing or treated with afungicide.

The wood lacks the strength, hardness, and at-tractiveness necessary for cabinetmaking, furni-ture, and similar uses. However, it is suitable forboxes, crates, interior sheathing, light construc-tion, toys, and similar products. After preserva-tive treatment, the wood could be used for sheath-ing, siding, and other exterior uses for which alight, easily nailed wood of moderate strengthis acceptable. It might also be suitable as a sub-stitute for the heavier grades of guano (balsa)if special techniques were developed to improveits machining characteristics.

ROBLE BLANCO (ROBLE)Tabebuia heterophylla (DC.) Britton (trumpet-creeper family, Bignoniaceae)

This wood is called roble blanco, or roble,meaning oak and white oak in Spanish, becauseof its superficial resemblance (fig. 68) to plain-sawed oak, although the wood lacks the charac-teristic wide rays of the oak group.

The heartwood is light brown with a grayishor somewhat. golden hue. Fine lines of brown-colored parenchyma provide the wood with a dis-tinctive and characteristic figure on quartersawedsurfaces and an attractive featherlike pattern onflatsawed surfaces. The sapwood is so similar incolor to the heartwood that it is very difficult toseparate the two.

The grain is straight to interlocked, with a dis-tinct ribbon stripe showing on quartersawed sur-faces where interlocked grain is present. Thetexture is medium to coarse, the luster is low to

medium, and no distinct odor or taste is appar-ent in seasoned wood. The wood is comparativelyheavy, weighing 42 pounds air-dry and 59 poundsgreen.

Roble blanco is a fairly easy wood to season.Green wood air-seasons rapidly with only moder-ate bow and very slight, twist. Other forms ofwarp and surface checking were not evident. in thePuerto Rican tests. Green 11/8-inch lumberreaches an air-dry moisture content of about 17percent, in 4 months or less under cover in the SanJuan area. The wood is also reported to kiln-drywith little degrade. Sap-staining fungi are notapt to be troublesome during seasoning.

The wood undergoes moderate and unusuallyuniform shrinkage during seasoning. Green


tained with all types of finishes.Roble blanco is considered an excellent wood for

wood shrinks at the rate of 1/8 inch (1.2 percent)per foot in width across the growth rings and 3/16inch (1.6 percent) per foot parallel to the growthrings in seasoning to 15 percent moisture content.Its longtitudinal shrinkage of 0.18 percent is nor-mal for a wood with interlocked grain.

Roble blanco saws and machines easily withvery satisfactory results in all operations exceptplaning, in which the interlocked grain causesconsiderable pickup. It has fair resistance toscrew splitting, takes nails fairly well, and glueseasily. The wood accepts mahogany and oakstains satisfactorily or can be finished naturallywith excellent results. A high polish can be ob-

veneer, but it requires careful and thorough boil-ing before slicing or turning. Considerable caremust also be taken to avoid torn and rough sur-faces during the veneering process. Quartercutveneers have an exceptionally attractive mottledfigure, dry evenly to a flat, smooth surface, andpossess good gluing properties.

The wood is tough and strong for its weight.It is similar to white oak and ash in all mechani-cal properties, particularly in stiffness, hardness,shear, cleavage, and shock resistance.

Roble blanco is moderately durable in contactwith the ground, but it is very susceptible to attackby termites and marine borers. It is rated onlyfair in weathering characteristics; the unpaintedwood loses its smooth surface and develops con-siderable checking upon exposure to weather,though it does remain free from warp.

In general, roble blanco is suitable for the sameuses as white oak and ash. Because of its goodworking properties and attractiveness, the woodis used extensively for furniture, cabinetwork, in-terior trim, and face veneer. It, is also well suitedfor use as flooring, millwork, boat decking, framesand planking, handles of all types, sporting goods,agricultural implements, and both light and heavy

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FIGURE 68.— Roble blanco: Top, flatsawed; bottom, quar-tersawed.

construction. The lower and less valuable gradesare suitable for boxes, crates, concrete forms, andsimilar items. Roble blanco’s moderate durabilityin the soil results in a limited use for posts, poles,and other products where durability is a factor.

SAMÁ N

Pithecellobium saman (Jacq.) Benth. (legume family, Leguminosae)

Samán is a moderately attractive wood that hassome favorable characteristics, but it is oftenvalued more as an ornamental than for its wood.The tree is often known as the rain-tree. It isnot native to Puerto Rico but has become widelynaturalized after extensive planting over manydecades.

Freshly cut samán heartwood (fig. 69) is a darkchocolate brown and distinct from the yellow tolight-cinnamon colored sapwood. Dry heart-wood is light to golden brown with darker streaks,resembling butternut (Juglans cinerea) of the

United States. The grain may be either straightor irregular; wood from slow-growing trees tendsto be more cross grained and have a darker colorthan that from fast-growing trees. The textureis medium to coarse, the luster is medium, andthere is no distinctive odor or taste. Samán issoft and light, weighing 33 pounds when air-dryand 68 pounds when green at 145 percent moisturecontent.

Because of the wood’s very high moisture con-tent, about 6 months is required to air-dry greenwood to 17 percent moisture content in the San


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FIGURE 69.— Samán : Top, flatsawed ; bottom,quartersawed.

Juan area. It also seasons rather poorly, withconsiderable degrade : moderate to severe bow and

crook, slight twist, and very slight cup. But sur-f ace checking or end splitting were not. observed inthe Puerto Rican tests. Sap-staining fungi mayalso develop on freshly sawed wood.

Samán undergoes uniform and exceptionallylow shrinkage during seasoning. Green woodshrinks 1/10 inch (0.7 percent) across the grainand 1/6 inch (1.2 percent) along the grain per footin width in drying to an air-dry moisture contentof 15 percent.

This wood saws and machines easily but usuallydevelops torn grain and fuzziness in pieces con-taining irregular grain. In the tests, samán wasrated poor in turning, fair in shaping and boring,and moderately good in planing, mortising, sand-ing, and screw splitting. It would probably ma-chine satisfactorily with special handling and theuse of more suitable machining techniques. Well-prepared material glues satisfactorily and takesan excellent finish with lacquer or varnish.

Samán is rated durable to very durable in re-spect to decay and is resistant to attack by dry-wood termites, rating well above Mexican ma-hogany and slightly above teak in this respect.

Though the tree IS valued mainly for its beautyand shade and to some extent for its sweet pods,which make excellent cattle feed, the lumber pos-sesses an attractive grain and color. It is suitablefor some types of furniture and cabinetwork, andfor light construction, boxes and crates, houseframing, and millwork. Samán’s good resistanceto decay and insects makes it suitable for specialuses where these qualities are important. Its lightweight and low, even shrinkage may also makeit suitable for patternmaking. It has been recom-mended for decorative veneer and plywood, in-terior trim, and paneling.

TABAIBA

Sapium laurocerasus Desf. (spurge family, Euphorbiaceae)

Tabaiba, or manzanillo (fig. 70), is a soft, light-weight wood of uniform pale-brown colorthroughout. The texture is rather fine except forthe fairly numerous large pores, which are visibleto the naked eye on the end grain and appear asfine scratches or stipple marks on flatsawed sur-faces. The grain is sometimes straight, more fre-quently tightly interlocked. The luster is medium.Growth rings are not visible, and characteristicodor and taste are not evident in seasoned wood.Air-dry wood weighs 28 pounds per cubic foot andgreen wood 46 pounds at 96 percent moisturecontent.

The wood is moderately difficult to season.Green lumber 11/8 inches thick air-seasons to about

17 percent moisture content in 6 months undercover in the San Juan area. A small amount ofdegrade occurs in the form of very slight twist andcrook, slight cup, moderate bow, and slight sur-face checking. No end checking or caseharden-ing were noted in the study. Green wood shrinksabout 1/16 inch (0.6 percent) per foot in widthacross the grain and 7/32 inch (1.8 percent) per footalong the rain in drying to 15 percent moisturecontent. Sap-staining fungi are almost certainto discolor freshly cut wood unless it is im-mediately immersed in a fungicide or allowed tobecome surface-dry soon after conversion.

Tabaiba saws and works easily with either handor power tools, with results varying from excel-lent in planing to very poor in sanding. Sawed


surfaces tend to be woolly, especially along thegrain. Frequent tearing, crushing, and fuzzinessoccur in all cutting operations except planing,with fair to poor surfaces resulting under con-ventional machining conditions. Better resultscould no doubt be attained if more favorable ma-chining conditions were used particularly thin-edged knives and saws and reduced spindle speeds.

The wood shows scratches readily in sandingbut works to a very smooth surface when fineabrasive paper is used. It has good resistance toscrew splitting. Gluing, staining, and polishingshould not be troublesome with well-sanded ma-terial.

Dry-wood termites and other insects, decay-causing fungi, and marine borers attack andquickly damage this wood, thereby resistrictingit to uses where good durability is not essential.Tabaiba is recommended for boxes, crates, interiorconstruction, and other uses requiring a light, soft,moderately strong wood. The wood has been rec-ommended for paper pulp and plywood and, afterpreservative treatment, should be suitable for sid-ing and other exterior uses.

F— 495377

FIGURE 70.— Tabaiba: Top, flatsawed ; bottom, quarter-sawed.

TABONUCO (GOMMIER)

Dacroydes excelsa Vahl (bursera family, Burseraceae)

Tabonuco, occasionally called candlewood,is the best known and most extensively used wood

The wood is moderately heavy, weighing 40pounds per cubic foot air-dry and 52 pounds

in the Puerto Rican forests. It is one of the most green. It is appreciably heavier than Mexicanplentiful timber species on the island. Long, mahogany but somewhat lighter than yellowclear logs of large diameter are harvested from birch, which it resembles superficially.centuries-old, hurricane-resistant trees in the rain Tabonuco air-seasons easily and satisfactorily.forests.

The heartwood (fig. 71) is a uniform brownGreen wood 11/8 inches thick air-dries rapidly

color with an overall pinkish cast when first cut,with only minor degrade in the form of very

turning a pinkish brown when seasoned and laterslight, cup, slight, box, twist, and end checking,

a lustrous brown when exposed. The narrow,and with no apparent surface checking or case-hardening. Green lumber will air-season to about,

indistinct, sapwood is is attractive grayish color.The texture is fine to medium, and uniform.

17 percent moisture content in 4 months underThe cover in the San Juan area.

grain is more or less roey and commonly inter-locked, creating an attractive ribbon stripe on the

The wood undergoes moderate and uniform

side surfaces. The luster is high, sometimes satinyshrinkage during seasoning and holds its placewell after manufacture. Green wood shrinks at

in appearance. Growth rings are not distinct.There is no distinctive odor or taste in seasoned

the late of 1/6 inch (1.4 percent) per foot in width

wood.across the growth rings and 1/3 inch (2.7 percent)per foot along the growth rings in seasoning to 15


F— 495378

FIGURE 71.— Tabonuco : Top, flatsawed ; bottom,quartersawed.

percent, moisture content,. The heartwood is notparticularly susceptible to sap-staining fungi, but.

the sapwood is often turned to a bluish gray byfungus action.

Tabonuco is a moderately good machiningwood. It cuts and saws easily but, because of anabundance of silica, rapidly dulls saw teeth andother cutting edges. Fairly good surfaces are ob-tained in planing, mortising, sanding, and shap-ing. Turning and boring are more difficult ; torngrain and occasional fuzziness occur in specimenshaving roey grain. The wood is easily glued andholds nails well. Mechanical tests show tabonucoto be moderately hard, tough, and strong, compar-ing well with Mexican mahogany and yellowbirch. The wood takes stain well and finishesbeautifully with varnish or lacquer; it is very dif-ficult to distinguish from mahogany when finishedto resemble that wood.

Tabonuco is only slightly resistant to decay,lasting 3 years or less in the ground, and it is verysusceptible to attack by both dry-wood and sub-terranean termites. Despite the presence of silica,the wood was quickly destroyed by marine borersin the Atlantic waters along the north coast ofPuerto Rico. Unfortunately, tabonuco is difficultto impregnate with preservatives by either pres-sure or nonpressure methods.

ofIn Puerto Rico, tabonuco is used for all typesfurniture and for cabinetwork, interior trim,

and general construction and carpentry. In otherareas of the Caribbean, it is used for crates, boxes,shingles, and small boats. It should be suitablefor soft-drink cases, fruit and vegetable contain-ers, and similar uses, and it has been recommendedfor decorative veneer. The wood is used exten-sively in Puerto Rico as a substitute for mahoganyin furniture manufacture and could be substitutedfor that, wood in many other products.

TECA (TEAK)Tectona grandis L.f. (verbena family, Verbenaceae)

Teca, teak in English, is one of the best knownand most highly valued timbers in the world.The tree is native to southeastern Asia and Malayabut has been planted successfully in Puerto Ricoand other areas in the American tropics.

Freshly cut heartwood (fig. 72) is olive greenwhen freshly cut, becoming a golden brown uponseasoning and exposure. The sapwood is yellow-ish to white in color and sharply demarcated fromthe heartwood. Growth rings are distinct and,except for occasional false rings, are of annualoccurrence. They show on the side surfaces asnarrow brown lines that are darker than the restof the heartwood.

Teca has unusually straight grain, uniformlyfine texture, an oily feel, and a strong, characteris-tic fragrance when freshly cut. Seasoned wood

retains its oily feel but possesses only a faint fra-grance and no detectable taste. Plantation-grownwood from Puerto Rico averages 40 pounds percubic foot when air-dry and 62 pounds green.

The wood air-seasons easily and satisfactorily.It also seasons rapidly, reaching 17 percent mois-ture content in 17 weeks under cover in the SanJuan area. A minor amount of warping occursduring air-seasoning, but no surface checking orcasehardening. Teca kiln-dries slowly but verywell, with little tendency to check, split, or warp.However, considerable variation occurs in the dry-ing rate of individual boards.

The wood is well known for its low and uniformshrinkage and excellent stability after manufac-ture and, accordingly, is the only wood acceptablefor decking on aircraft carriers and other large


vessels. Green wood shrinks approximately 1/16inch (0.5 percent) per foot in width across thegrowth rings and about 1/8 inch (1.1 percent)along the growth rings in seasoning to 15 percentmoisture content.

Teca is, in general, comparable to white oakin strength. Plantation-grown wood is equallyas strong as forest-grown wood. Air-dry woodaverages about 10 to 20 percent stronger in bend-ing and stiffness than oak but is inferior in hard-ness by a like amount.

Plantation-grown teca works easily with bothhand and power tools, but it contains silica whichdulls cutting edges. Special carbide or otherhigh-quality steel cutting edges are recommended,although ordinary good-quality knives are usedsuccessfully with reduced spindle speeds.

radius of curvature.

In the tests, teca gave good to excellent resultsin all operations except sanding, in which veryfine abrasives are required to prevent visiblescratching of the wood. Under ordinary condi-tions there is a tendency for roughness to occuron the end grain in shaping operations. Tecatakes nails fairly well, glues moderately welldespite its oily nature, and can be varnished andpolished with good results. It is a moderatelygood wood for steam bending, but it is likely tobuckle on the concave surface if bent to a small

The heartwood is resistant to attack by dry-woodtermites, being comparable to West Indies mahog-any (Swietenia mahagoni) in this respect. It isalso moderately resistant to subterranean termitesand very durable in the ground, but it is readilyattacked by marine borers. The sapwood sharesnone of the durability properties of the heartwood,being readily attacked by all the above-namedorganisms in addition to being vulnerable todamage by pinhole borers.

The heartwood is extremely difficult to impreg-nation with preservatives, because only the vesselsabsorb the solution. The sapwood is not difficultto treat and can be impregnated successfully bythe open-tank process. Treating the outer sap-wood layer of small round or split posts by thismethod adds considerably to their service life.Unpainted wood possesses excellent weatheringcharacteristics and is almost entirely free fromwarp and checking when exposed without theprotection of paint.

F— 495379

FIGURE 72.— Teca : Top, flatsawed ; bottom, quartersawed.

Teca is best known for its attractive use in shipdecking, for which no other wood is its equal. Ithas many other uses, including flooring, joinery,interior trim, durable outdoor structural work,door and window frames, carvings, furniture,doors, interior paneling, and fancy turned items.The wood’s low and even shrinkage, stability, anddurability suits it exceptionally well for tanks andvats. Because of its high resistance to acids, thewood is also very useful in laboratories and chemi-cal plants for benches and other fixtures. Thin-nings from teca plantations are often split andused in the manufacture of wire fencing, squaredfor house framing, treated and used as roundposts, or sawed into lumber for furniture.

UCARBucida buceras L. (combretum family, Combretaceae)

Ucar is also known in English as oxhorn bucida. quently has a roey grain. It is a dark greenishShort logs of medium to large diameter are ob- brow-n clearly demarcated from the yellowish totained in limited numbers from the semiarid light-brown sapwood. Longitudinal stripes areforests along the south coast of Puerto Rico. frequent as a result of the roey grain, giving the

The wood of ucar is very hard, heavy, and wood an attractive figure on the side surfaces. Thestrong. The attractive heartwood (fig. 73) fre- wood is moderately fine in texture, very lustrous,


F— 495380

FIGURE 73.— Ucar : Top, flatsawed ; bottom, quartersawed.

and without distinct, growth rings. Althoughgreen wood has a tarry odor, seasoned wood has nocharacteristic odor or taste. Sir-dry wood weighsabout 69 pounds per cubic foot and green woodabout 79 pounds per cubic foot, making it one ofthe heaviest woods available for general use onthe island.

The wood is moderately easy to season; it air-dries satisfactorily for a timber of its high density.Green 11/8-inch lumber air-seasons to 17 percentmoisture content in 6 months under cover in theSan Juan area. A moderate amount, of warpingand surface checking and a minor amount ofend checking occur during the seasoning process.

Shrinkage is unusually low and uniform for a

Ucar is a poor bending wood, but it is other-wise an exceptionally strong wood, resemblinggreenheart (Ocotea rodiaei) in both weight andstrength properties. It is sawed into lumber andplanks in Puerto Rico and is used in carts, gates,wooden fences, and occasionally for the construc-tion and repair of farm buildings. Ucar is alsoparticularly well suited for heavy-duty flooring,work benches, machinery platforms, and heavy,durable exterior construction of all types. Thewood is not suitable for decorative purposes infurniture and cabinetmaking and is too difficultto work for general building purposes. Becauseof its great strength and good durability, ucar isused in other countries for railway ties, piling innonteredo areas, house posts, and to some extentfor bridge timbers. The wood may be suitable forcertain machinery parts and sporting goods re-quiring a heavy, hard, and extremely strong wood.Its technical properties also indicate that it, mightbe useful as a substitute for greenheart except formarine use in teredo-infested waters.

YAGRUMO HEMBRA

wood of its density. Green wood shrinks 5/32 inch(1.3 percent) per foot across the growth ringsand 9/32 inch (2.3 percent) per foot along thegrowth rings during seasoning to an an-drymoisture content of 15 percent.

Ucar is rather difficult to saw and machine withpower tools and is very hard to work with handtools because of its very high density and hardness.However, very smooth glasslike surfaces are ob-tained in all operations except planing, in whichtorn grain is troublesome in pieces containingroey gram.

Although good, clean holes can be cut in boringand mortising, the bits tend to heat and char theinterior of the holes. If sufficient power is avail-able, charring can be prevented by an increasedrate of speed. Because the wood is easily splitby screws or nails, it is necessary to prebore suf-ficiently large lead holes to reduce splitting to anacceptable minimum. Well-sanded wood takes anexcellent polish with all types of finishes.

Ucar is resistant to dry-wood termites and dur-able in contact with the ground, but it is not con-sidered resistant to marine borers. Its resistanceto impregnation with preservatives is probablyhigh. Sap-staining fungi, pinhole borers, andother insects are not troublesome in either the logsor sawed lumber.

Cecropia peltata L. (mulberry family, Moraceae)

Yagrumo hembra is one of the lightest woodsgrowing in Puerto Rico, but it is especially toughfor its weight. The tree grows rapidly and is shortlived, producing small to medium-size logs with acharacteristic hollow between the nodes. It. isfrequently called trumpet-tree in English.

The wood (fig. 74), which appears to be allsapwood, is whitish when freshly cut, becoming apale-brown to oatmeal color upon exposure. Itis soft but fairly lustrous, coarse textured, andgenerally straight grained. Green wood, con-taining 125 percent moisture content, weighs 41


pounds per cubic foot. Air-dry wood at 15 per-cent, moisture content weighs about 22 pounds percubic foot as compared with an average of 17pounds for guano growing in Puerto Rico.

The wood seasons rapidly, reaching a moisturecontent of about 17 percent in 14 weeks whenpiled under cover in the San Juan area. In theinitial tests, air-seasoning was accompanied byrather severe bow and twist, and moderate cup-ping and crook.9 However, it usually seasonswithout noticeable surface checking or end split-ting. Some difficulty is encountered with sap-staining fungi if the lumber is not treated witha fungicide or allowed to become surface-dry im-mediately after sawing.

Yagrumo hembra underwent moderate but ex-ceptionally uneven shrinkage during the initialseasoning tests. Shrinkage from green to oven-dry averaged 1/4 inch (2.0 percent) across thegrain and 3/4 inch (6.2 percent) parallel to thegrain per foot in width. The better than 3 to 1ratio of tangential to radial shrinkage is unusuallyhigh and accordingly subject to question.Shrinkage from green to air-dry is normally aboutone-half of these values.

Dry, seasoned wood is very easy to saw andmachine compared with green wood, which ad-heres to the face of circular saws. Because ofyagrumo hembra’s soft, wood, surfaces tend to tearand fuzz in shaping and turning, and to crush orcrumble in boring and mortising. However, ittakes screws and nails readily, holds them firmly,and gives good results in planing and sanding.Trouble is often encountered in obtaining asmooth finish with varnish or lacquer, because ofthe soft, porous nature of the wood and a ten-dency for fuzziness to develop during the finishingprocess.

Yagrumo hembra is very susceptible to decay,termites, pinhole borers, and other insects and isconsidered nondurable in contact with the ground.It is used for match sticks, boxes and crates, ex-celsior, interior boarding, and other uses for which

9 Later tests indicate that yagrumo hembra can be air-seasoned quickly and without excessive degrade undersome conditions. This would also indicate a more favor-able ratio of tangential to radial shrinkage than thevalues listed here.

F— 459381

FIGURE 74.— Yagrumo hembra : Top. flatsawed; bottom,quartersawed.

a soft, easily worked wood of low durability andstrength is acceptable. The wood should be en-tirely acceptable as a substitute for guano in themanufacture of toys, models of all types, andother commercial products for which the mod-erately heavy grades of balsa are acceptable.Yagrumo hembra is used for paper pulp in someareas.

This wood is used in Puerto Rico for the manu-facture of excelsior and, in combination withcement, is made into a type of insulation boardsuitable for certain light interior construction andpartitions.

YAGRUMO MACHODidymopanax morototoni (Aubl.) Dec. & Planch. (ginseng family, Araliaceae)

Yagrumo macho, or matchwood, is a small tomedium-sized tree found only in the rain forest in

weighs about 28 pounds per cubic foot and greenwood about 40 pounds per cubic foot at 81 per-

openings created by clearing, hurricanes, or other cent moisture content.catastrophes. The wood (fig. 75) is a pale- The wood seasons rapidly but with considerablebrownish color throughout, without distinctionbetween heartwood and sapwood. It is lustrous,

degrade. Green lumber 11/8 inches thick air-seasons to about 16 percent moisture content in 14

has fairly fine texture and straight grain, and it is weeks under cover in the San Juan area. Degradesoft and firm yet quite brittle. Air-dry wood occurs as moderate to severe warping, but without

596033 O— 61— — 7

94 U.S. DEPT. OF AGRICULTURE’ HANDBOOK NO. 205

F— 459382

FIGURE 75.— Yagrumo macho : Top, flatsawed ; bottom,quartersawed.

apparent surface checking or end splitting. Greenlumber is discolored quickly after sawing by sap-

staining fungi unless the surface moisture is lostwithin a few hours or the wood is immersed in afungicide.

A rather high rate of shrinkage occurs duringseasoning for a wood of yagrumo macho’s density,but this shrinkgage is fairly uniform in the radialand tangential directions. Green wood seasonedto air-dry condition shrinks at the rate of 3/8 inch(3.1 percent) acre the growth rings and 2/3 inch(5.6 percent) along the growth rings per foot inwidth.

Yagrumo macho works easily with either handor power tools. Good results are obtained inplaning, shaping, and sanding except for oc-casional fuzziness in some pieces. However, thewood is difficult to turn, bore, or mortise; exces-sive tearing and crushing of the fibers occurs dur-ing these operations. The use of very sharp andthin cutting edges and reduced feed rates wouldhave improved the quality of the machined sur-faces. The wood takes nails and screws very wellwithout splitting. Polishing is somewhat difficult,,with a tendency for woolliness to occur duringrubbing and after application of the finishes.

Yagrumo macho logs are very susceptible todamage by pinhole borers unless removed fromthe forest and converted into lumber soon afterfelling. Seasoned lumber is very susceptible totermites and other insects, decay, and marineborers; it requires preservative treatment for usein exposed locations or in contact with the ground.

Yagrumo macho is an excellent wood for boxesand crates, and it has been recommended for matchsplints, interior construction, utility grade ply-wood, and toys. It may also have good pulpingproperties and should be suitable for many of thesame purposes as the heavier grades of guano(balsa).

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