Post on 10-Jan-2016
description
26
Paint Mixing and Reducing
Chapter
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Objectives
After studying this chapter, you will be able to:• Know where to find a paint code on a vehicle.• Understand how to use the paint code to obtain the
paint part number.• Understand the importance of thoroughly stirring
tints.• Explain how to mix a color.• Know how to reduce paint by volume, percentage,
and weight.
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing
• Paint code– Letters, numbers, or combination– Represents color of vehicle– Paint code location varies by vehicle manufacturer
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Paint code– Date of vehicle manufacture– Code may be same for different years
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Paint part number– Number assigned by specific paint manufacturer– Unique to each paint manufacturer– Different paint part number for each paint code
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Paint part number– Find paint part
number with paint code
• Color chip book• Paint code/paint
part number CD• Paint
manufacturer’s web site
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Alternate paint part numbers– Same paint code– Slightly different color on vehicle– Reasons for different colors
• Vehicles built at different factories• Different paint manufacturers• Spraying conditions, equipment at factories are
different
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Alternate paint part numbers– Alternate deck
of color chips– Check chip
against vehicle– Select best
matching alternate
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Alternate paint part numbers– Underhood color
• Similar to exterior color• Lacks metallic or pearl
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Paint sources– Jobber
• Sells paint• Mixed by jobber• Sells factory-pack color paint• Supplied by paint manufacturer
– Intermix• Mixed at shop • Uses tints supplied by jobber
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Paint mixing equipment– Digital scale
• Weighs tints• Accurate to 100th of a
gram• Digital readout• Zero scale by pressing
bar
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Paint mixing equipment– Tint mixing bank
• Stirs and stores tints
– Paint shaker• Stirs tints
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Paint mixing supplies– Tints
• High-strength• Low-strength• Powder pearl• Metallic tint
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Paint mixing supplies– Binder
• Forms paint film when dry
– Balancer• Corrects ratio of pigment to binder• Flake control
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Paint mixing supplies– Comprehensive tint system
• Add tints to create paint
– Single tint system• Add tints, binder, and balancer to create paint
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Paint formula– Recipe for specific color– List of tints– List of weights of each tint
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Paint formula– Quantitative formula
• Lists required weight of each tint
– Cumulative formula• Lists weight of entire mixture as each tint is added
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Color creation– Stir tints for 15 minutes twice per day– Stir new tints for 30 minutes– Stir tints five minutes before mixing color– Do not mix waterborne paint in metal cans– Remove dried tint from pour spout
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Color creation– Recheck tint number before adding to can– Concentrate while pouring– Add tints to center of can– Start with clean paint can– Follow formula– Add specified amount of each tint
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Mixing (Cont.)
• Overpour– Add too much of one tint– Remove excess tint– Some scales can recalculate
• Paint can label– Contains safety information– Lists paint part number– May attach printout of formula
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction
• Stirring– Paint must be uniform before reduction– Heavier paint components settle out– Scrape solids off bottom if settled– Do not shake waterborne paint– Seal lid in place– Unsealed lid allows solvents to escape
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
• Reducer type– Match to spray booth temperature
• 60– 70F low-temp reducer• 70– 85F mid-temp reducer• Above 85F high-temp reducer
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
• Hardener type– Temperature rated– Intended usage rated– Surface cure
• Amount of time paint will stay wet • Absorb overspray
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
• Hardener type– Spot-rated
• Fast surface cure
– Panel-rated• Intermediate surface cure
– Overall-rated• Slow surface cure
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
• Viscosity– Thickness of
paint– Measure with
viscosity cup– 18 – 22 seconds
for most paints
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
• Viscosity– High-viscosity value
• Paint too thick
– Low-viscosity value• Paint too thin
– Sprayable range
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
– Part reduction– Percentage reduction– Combination volume reduction
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
Volume reduction• Part reduction
– Instructions given as ratio• For example, 4:1 = four parts (units) of one substance
to one part of another substance
– Mixing stick• Contain lines indicating units• Must have straight-sided container
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
• Part reduction using mixing stick with equal increments marked (4:1:1 mixing ratio)
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
• Part reduction using dedicated paint mixing stick
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
• Part reduction– Graduations
• Units on paint mixing stick
– Mixing cup• Has various mixing ratios • Select correct ratio
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
• Percentage reduction– Uses percent of volume
• Combination volume reduction– Uses both parts and percentage
Permission granted to reproduce for educational use only.© Goodheart-Willcox Co., Inc.
Paint Reduction (Cont.)
• Weight reduction– Use scale– Weigh out
components– Produces
desired volume of paint
– Volume mixing ratio cannot be used