Paint Defects

PAINT DEFECTS

1st November 2001/aka

CONSUMER BUYS

• THE PAINTED SURFACE

• TIME PERIOD BETWEEN TWO PAINT APPLICATION CYCLES

BEST BUY

DEPENDS ON• THE RIGHT SURFACE CONDITION

• THE RIGHT SURFACE PREPARATION

• THE RIGHT PAINT COMPOSITION

• THE RIGHT APPLICATION WITH RIGHT TOOLS

• THE RIGHT ENVIRONMENT

PRODUCT TRAINING PROGRAMME

PAINT DEFECTS

STAGES OF DEFECTS

• IN WET PAINT

• DURING APPLICATION

• DURING DRYING AND CURING

• SHORTLY AFTER APPLICATION

• DURING SERVICE LIFE

DEFECTS APPEARING IN

WET PAINTS

PRESENTATION ON

DEFECTS

• PROBABLE CAUSES

• PROBABLE CORRECTIVES

DEFECTS IN WET PAINTS

FOAMING• OVERSTIRRING• LOW

CONSISTENCY• TRANSPORTATION

• DUMPING OR ADDITION

• ALLOW THE MATERIAL TO STAND STILL

GAS FORMATION-BULGING

• REACTION OF METALLIC PASTE

BASIC PIGMENTS

BINDERS• PUTREFACTION• MOISTURE• STORAGE

TEMPERATURE

• CAREFULLY

ALLOW GAS TO GO OUT

• CHECK VISCOSITY IF IT CAN BE

ADJUSTED FOR USE

GELLED

• REACTION ON STORAGE

• EXPOSED TO HIGH TEMPERATURE

• MOISTURE

• DISCARD

HARD SETTLING

• OLD MATERIAL• HEAVILY

PIGMENTED• LOWER

CONSISTENCY• STORAGE IN

ELEVETED TEMPERATURE

• STIR WELL FOR LONGER TIME

• USE GYROSHAKER

• KEEP TIN UPSIDE DOWN FOR SOME TIME

LUMPS

• SMALL

• BIG

• HARD

• SOFT

(Distempers)

LUMPS

• MATERIAL IS EXPOSED TO AIR FORMING SKINS AND / OR SMALL LUMPS

• MIX WELL FOR LONG TIME

• FILTER THE MATERIAL BEFORE USE TO AVOID LUMPS

MEDIUM SEPARATION

• MATERIAL IS OLD• TENDENCY

EXIBITED BY MANY FORMULATIONS

• IT IS NOT A QUALITY RELATED ISSUE

• MIX WELL AND USE

PUTREFACTION

UNPLEASANT SMELL• MICROBIAL

CONTAMINATION FROM RM,WATER USED;MATERIAL LEFT EXPOSED AFTER THINNING WITH WATER

• IF THERE IS NO CHANGE IN CONSISTENCY USE MATERIAL;

OTHERWISE DISCARD

SKINNING

• MORE ULLAGE• LEAKAGE OF AIR• FAULTY

FILTRATION• PART OF PAINT

REMOVED AND LID IS NOT TIGHTLY CLOSED

• COVER THE TOP LAYER WITH SMALL QUANTITY OF THINNER

• FILTER WELL PRIOR TO USE

SYNERESIS WATER/LIQUID SEPARATION

• OLD MATERIAL• LOW

CONSISTENCY• OVERTHINNING

OF MATERIAL


•THIN IN CONSISTENCY

• INEFFECTIVE STIRRING WHILE ASSESSING CONSISTENCY

• DROP IN VISCOSITY ON STORAGE

• SYNRESIS


• HAVE A SKILLED BRUSHMAN TO AVOID SAGGING

PICKUP IN CONSISTENCY THICKENING/ VISCOUS MATERIAL

• REACTION• EXPOSED TO

HIGH TEMPERATURE

• MOISTURE

• ADJUST CONSISTENCY AND USE

• IT MAY TAKE MORE THINNER AFFECTING OPACITY

DIFFICULTIES DURING

APPLICATION OF PAINT

BITTY FILM

• DUSTY SURROUNDINGS

• UNFILTERED MATERIAL

• SEEDING-OVERTHINNING RAPIDLY

• UNSUITABLE THINNER

• SEEDING WILL RESULT BITTY FILM

• IN OTHER CASES FILTER AND USE

BLEEDING

• USE OF IMPROPER PRIMER OR THINNER ( STRONG

SOLVENTS)• INSUFFICIENT

CURING OF BASE COAT

• USE OF LOCAL DYES/ STAINED WOOD

• RIGHT THINNER• RIGHT

UNDERCOAT• CURE WELL• PROPER QUALITY

OF WOOD

BLOOMINGOR HAZE

• IMPROPER THINNER

• POOR VENTILATION

• CONTAMINATION• HIGH HUMIDITY• CONDENSATION

ON SUBSTRATE

• RIGHT THINNER• GOOD

VENTILATION• AVOID

CONTAMINATION

BLUSHING

• ACTION OF MOISTURE / WATER UNDER HIGH HUMIDITY

• WARM THE PARTS BEFORE PAINTING TO ,SAY AT 40ºC

• FORCE DRY THE FRESH FILM DURING COOLER DAYS

BRUSH CLOGGING

POOR BRUSH CLEANING

(DISTEMPERS)

BRUSH CLOGGING

• HARD WATER• USE OF BRUSH

PARTIALLY USED-UNCLEANED

• USE SOFT WATER• MAINTAIN BRUSH

PROPERLY

BRUSH MARKS

• HIGH CONSISTENCY

• WRONG THINNER

• MATERIAL DRIES FAST

• HIGH SURROUNDING TEMP

• POOR QUALITY OF BRUSH

• POOR WORKMANSHIP

• PROPER CONSISTENCY

• RIGHT THINNER

• QUALITY BRUSH

• GOOD WORKMANSHIP

HARD TO BRUSH


• TEMP HIGH (Evaporation of solvents)

• HIGH CONSISTENCY(Tin left opened)

• LOWER TEMP(Visc pickup)

• POROUS SUBSTRATE

• FIRST COAT SOFT

• RIGHT THINNER

• RIGHT WEATHER

• CURING OF UNDERCOAT

CISSING

• CONTAMINATION• POOR WETTING

(at end of pot life)• PAINT IS TOO

THIN

• GOOD SUBSTRATE PREPARATION

• RIGHT CONSISTENCY

• AVOID CONTAMINATION

DIFFICULT TO MIX WITH WATER

(WATER BASE PAINTS)

DIFFICULT TO MIX WITH WATER

• HARD WATER• HIGH

CONSISTENCY• DUMPING OF

PASTE IN WATER

• USE SOFT WATER• MIX SLOWLY AND

WELL

LIFTING OF UNDERNEATH FILM

(AFTER THE APPLICATION OF TOP COAT)

LIFTING OF UNDERNEATH FILM

• STRONG SOLVENTS IN TOP COATS

• IMPROPER CURING OF UNDERCOAT

• APPLICATION OVER UNCLEAN SURFACE

• PROPER THINNER• CURE

UNDERCOAT• RIGHT

COMPOSITE SYSTEM

• USE TIE COAT

ORANGEPEEL EFFECT


• SETTING OF GUN

• FILM SETS FAST

• LOW FILM OR TOO HIGH DFT

• SUBSTRATE TEMP HIGH

• UNDERCOAT NOT DRIED WELL

• PROPER THINNER• CURING OF

UNDERCOAT• RIGHT

ATMOSPHERE• GOOD

WORKMANSHIP

PINHOLES

• CONTAMINATION• WETTING POOR

(Two Pack)• SILICON

CONTAMINATION• POOR FLOW



POOR SPREADING CAPACITY OR POOR COVERING CAPACITY

• APPLICATION AT HIGHER CONSISTENCY -THICK FILM


• HIGH ABSORPTION DUE TO POROUS SUBSTRATE


• RIGHT THINNER• SEAL THE

SUBSTRATE TO REDUCE POROSITY

POOR HIDING

• OVERTHINNING• LOWER DFT• CONTRAST OF

BASE COLOR• SETTLED MASS IN

A CAN NOT FULLY MIXED

• FLOCCULATION OF PIGMENT

• MIX WELL• GOOD

WORKMANSHIP• APPLY PRIMER

TO REDUCE CONTRAST

SAGGING


• HIGH DFT

• GUN SETTING

• PAINT OVER GLOSSY SUBSTRATE

• WET PLASTER

• INSUFFICIENT MIXING OF PAINT ( SETTLED MASS )



• RIGHT THINNER• PROPER SURFACE

PREPARATION

WRINKLING

• THICKER FILM BUILDUP

• HIGH TEMP• VISCOUS

MATERIAL• SURFACE DRY

WITH TRAPPING OF SOLVENTS

• CONTAMINATION

• GOOD VENTILATION



FAULTS RELATED TO

DRYING & CURING

DISCOLORATION DUE TO OVERBAKING,OR YELLOWING DUE TO

OVERBAKING

• BAKING AT HIGHER TEMPERATURE

• BAKING FOR LONGER DURATION

• CONTROL PROPER SCHEDULE

SLOW DRYING

• HIGHER DFT• LOW

SURROUNDING TEMP

• HIGH HUMIDITY• CONTAMINATION

OF OILY ,WAXY MATERIAL


• GOOD SURFACE• RIGHT THINNER• RIGHT

ATMOSPHERE• GOOD

WORKMANSHIP

SOFT FILM FILM IS CHEESY


SURROUNDING TEMP


• CONTAMINATION WITH OIL WAX

• RIGHT THINNER• GOOD

VENTILATION• RIGHT

ATMOSPHERE• GOOD

WORKMANSHIP

FILM IS TACKY FILM IS STICKY


SURROUNDING TEMP


• CONTAMINATION• SAPONIFICATION• DAMP WALL

• RIGHT THINNER• RIGHT

ATMOSPHERE• SEAL ALKLINITY• GOOD

WORKMANSHIP

BLISTERS

• IMPROPER THINNER• AERATION IN PAINTS• MOISTURE

CONTAMINATION• THICK FILM WITH

ENTRAPPED SOLVENTS

• WATERLOVING SALTS IN BASECOAT

• MOISTURE MORE THAN 12%

• RIGHT THINNER

• SEASONED WOOD

• AVOID CORROSION

• RIGHT DFT

• PROPER CURING

COLOR STREAKS

• UNDISPERSED TINTERS

• PIGMENT FLOCCULATION

• NON UNIFORM BRUSHING


• PROPER MIXING OF MATERIAL

DEFECTS SHORTLY

AFTER APPLICATION

FINISH OF THE FILM

GRITTY OR ROUGH OR FINISH OF THE FILM

POOR

FINISH OF THE FILM POOR

• UNFILTERED MATERIAL

• UNCLEAN SUBSTRATE• DUSTY SURROUNDING• DUMPING OF

THINNER• STIRRED-IN-SKIN• PIGMENT

FLOCCULATION

• FILTER WELL• CLEAN

ENVIRONMENT• SELECT AND ADD

RIGHT AMOUNT OF THINNER

MATTENING OF THE FILM

DIFFERENCE IN SHEEN/MATTNESS

MATTENING OF THE FILM


• THIN FILM• HIGH POROSITY

OF THE SUBSTRATE OR PRIMER/UNDER

COAT

• SEAL THE SUBSTRATE

• SELECT PROPER THINNER


PATCHINESS

• NON UNIFORM ABSORPTION

• NONUNIFORM APPLICATION OF PRIMER

• POOR PUTTY WORK

• THIN FILM

• POOR DISPERSION OF TINTERS

• POOR WORKMANSHIP

• UNIFORM DFT• PROPER MIXING

AND STIRRING• CORRECT

APPLICATION• QUALITY TOOLS• SEALING OF

SURFACE

POOR ADHESION

ADHESION ON GALVANISED,COPPER OR

ALUMINIUM

POOR ADHESION

• POOR SURFACE PREPARATION

• ETCH PRIMER?

• PRETREATMENT CHEMICALS

• CHALKY SURFACE

• CONTAMINATION

• POOR CURING OF UNDERCOAT

• INCOMPATIBILITY OF COATS(THERMOPLASTIC VS THERMOSETTING)

• SELECT RIGHT SYSTEM

• GOOD SURFACE PREPARATION

• CURE WELL THE COATS APPLIED IN BETWEEN

POOR GLOSS

• INCOMPATIBLE THINNER


• VERY THIN COAT• HIGH

ABSORPTION OF THE SURFACE

• PRIME THE SURFACE

• USE PROPER THINNER

• ENSURE GOOD VENTILATION


SHADE VARIATION

• NONUNIFORM FILM DEPOSIT

• COLOR OF THE U/C• NO. OF COATS

APPLIED• FLOCCULATION• DIFFERENCE IN

APPEARANCE OF TOP COAT(GLOSS)

• CONTAMINATION WITH OTHER COLOR

• MIX THE MATERIAL WELL


REDUCED SHEEN(LUSTRE FINISH)


• ABSORPTION OF UNDERCOAT / SURFACE

• NONUNIFORM DFT

• SETTLED MASS IN CAN-?

• MIX WELL • SELECT RIGHT

THINNER• GOOD

WORKMANSHIP

DEFECTS DEVELOPED DURING

SERVICE LIFE

ALGAE GROWTH

• PRETREATMENT TO THE AFFECTED SURFACE PRIOR TO PAINTING

• MOIST/HIGH HUMIDITY

• DAMP SURFACE

• TREAT WITH BIOWASH

• AVOID DAMP WALL

• STOP THE LEAKAGE OF WATER

• GOOD WEATHER

CHALKING

• IMPROPER SURFACE ABSORPTION

• OVERTHINNING OF W/B -SETTLING

• UV RADIATION

• TOO THINLY APPLIED FILM

• SALTY ATMOSPHERE

• SELECT RIGHT PRODUCT


CHECKING & CRACKING

• SEVERE WEATHER CONDITION

• OVERAGEING OF FILM

• DIFFERENCE IN STRESS AND STRAIN IN MULTICOAT SYSTEM

• SELECT RIGHT PAINT COMPOSITE SYSTEM

EFFLORESCENCE

• SEEPAGE OF WATER THROUGH WALL-SALTS DEPOSITION

• SALTS FROM BRICKS

• UNWASHED SAND IN MORTERS OR CEMENT ADDITIVES

• STOP SEEPAGE• REMOVE POWDER• WASH WELL• DRY SURFACE• PRIME AND

APPLY

FUNGUS GROWTH OR MOULD GROWTH

• AFFECTED SURFACE PRIOR TO PAINTING

• HIGH HUMIDITY• LACK OF

SUNSHINE• POOR

VENTILATION• DAMP ROOMS

• TREAT WITH BIOWASH

• SELECT RIGHT SYSTEM

• RIGHT WEATHER CONDITIONS

PEELING & FLAKING• DIFFERENTIAL STRESS

AND STRAIN IN MULTICOAT SYSTEM

• PREMATURE DETACHMENT OF U/C

• POOR ADHESION• UV EXPOSURE• POOR SUBSTRATE• DAMP PLASTER• EFFLORESCENCE

• RIGHT PAINT SYSTEM

• RIGHT SURFACE PREPARATION


RUSTING

• RUSTY SURFACE• POOR QUALITY

OF PRIMER• HIGH HUMIDITY• CORROSIVE

ATMOSPHERE


• RIGHT SURFACE PREPARATION


DARKENING OF SHADE

• OVER EXPOSURE TO SUNLIGHT

• ALKALINE -ACIDIC CONTAMINATION

• LOSS OF GLOSS

• RIGHT PRODUCT SELECTION

FADING OF SHADESHADE IS BECOMING LIGHTER

• OVEREXPOSURE TO SUNLIGHT

• TINTED WITH LOCAL COLORANTS

• MOISTURE

• CHALKING MASKS

• LOSS OF GLOSS

• ACIDIC CONTAMINATION


YELLOWING OF SHADE• INADEQUATE EXPOSURE

TO SUNLIGHT

• ADDITION OF GLAZE VARNISH

• UNDERNEATH SURFACE RUSTY

• OVERBAKING

• CONTAMINATION-AMMONIA

• PAINTED AREA PARTIALLY COVERED

• GOOD SURFACE PREPARATION


THANK YOU

Paint Defects

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