Paint - Basecoat/Clearcoat Repair Systems
Bulletin: 85-10-1ADate: Mar 1985
Ref. No.: 85-182-10
SUBJECT: BASECOAT/CLEARCOAT REPAIR SYSTEMS
MODELS AFFECTED: 1985 ELECTRA
NOTICE: This bulletin supersedes 85-10-1 dated March 1984. Changes have been made in the procedure. Please disregard original bulletin and replace it with this one.
The repair systems contained in this bulletin are recommended as a guide when repairing basecoat/clearcoat exterior finishes on the above styles.
The following are procedures outline a method for making spot/partial and full panel repairs on nonflexible parts and full panel repairs on flexible parts.
FIGURE 1 - TYPICAL SPOT/PARTIAL REPAIR USED ONLY ON QUARTERS & ROOFS:
FIGURE 2 - TYPICAL FULL PANEL REPAIR WITH LACQUER OR ENAMEL CLEARCOAT:
NONFLEXIBLE PANEL REPAIR SYSTEM
Procedure - Spot/Partial Repair with Blending (Figure 1) and Full Panel Repair (Figure 2)
Basecoat - Lacquer or Enamel
1. Wash with a mild detergent and water to remove any water soluble contaminates, then clean with wax and grease removing solvent to remove any tar, silicone or other road film not removed with the detergent wash.
2. Repair and featheredge damaged area(s) as required.
3. If substrate is metal, treat surface with a metal conditioner and conversion coating according to label directions. Allow to dry thoroughly and apply primer-surfacer to repair area. Allow to dry 20-30 minutes before sanding.
4. Using wet or dry #400 grit sandpaper or finer, sand entire area(s) to be refinished with the basecoat color. Areas to be clear coated only, should be wet sanded with #600 or finer sandpaper or hand compound (follow manufacturers recommendations) .
5. Reclean panel(s) with wax and grease removing solvent and then tack wipe.
6. Apply one or two coats of adhesion promoter within moldings and/or breaklines of the panel section(s) to be refinished. When making paint repairs to areas such as quarter panels where the repair is not confined within moldings or breaklines, apply adhesion promoter a minimum of 4-6" onto adjacent panel. Adhesion promoter must extend beyond the area to be covered by the clear coat when not confined by molding (Figure 1). Allow to flash a minimum of 30 minutes before applying base color coat. Some enamel basecoat may be require adhesion promoter. Follow manufacturer's recommendations.
7A. Polyurethane Enamel Basecoat
CAUTION: There are a number of paint systems available for service use: however, may require additives containing isocyanates. It is essential that all recommendations and warnings listed on the container label for materials selected be followed.
It is mandatory that adequate respiratory protection be worn.
Examples of such protection are: 3-M models #6984 and #6986 disposable respirators.
Such protection should be worn during the entire painting process. Persons with respiratory problems, or those allergic to isocyantes must not be exposed to isocyanate vapors or spray mist.
a. Following paint manufacturers' label directions, activate the Polyurethan Enamel material. Mix material thoroughly. Pot life of activated mixture is approximately eight (8) hours.
b. Reduce basecoat per label directions. Some activated Polyurethane Enamel materials are ready to spray as packaged under normal conditions. As conditions vary, to enhance flow out and leveling up to 10% more than the specified enamel reducer may be added to the activated mixture. Check the viscosity of the activated mixture with a Zahn #2 Paint Viscosity Cup or its equivalent. Follow the paint manufacturer's labeled recommendations for paint viscosity cup reading.
c. Using manufacturers specified air pressure at the gun, spray two medium-wet coats of enamel mixture to achieve full hiding. Allow first coat to set-up for 15-20 minutes before applying the second final coat. Unless manufacturer recommends otherwise allow to cure overnight.
7B. Lacquer Basecoat
a. Reduce base color 150-200% with an extra-slow drying lacquer solvent. The viscosity of the reduced base color is very important in order to match the OEM (original equipment manufacturers) finish. The best
way of checking the viscosity of a reduced paint material is with a Zahn #2 paint viscosity cup or equivalent. If a cold can of paint is brought into an average temperature room (65-70~), it will be thicker and more viscous. Adding solvent to make the paint sprayable is not the best action. The paint should be allowed to reach workable, or average room termperatures. Follow manufacturer's recommended paint viscosity cup reading for their material.
b. Spray base color at 35-45 lbs. air pressure at the gun or as specified by the paint supplier. Apply only the number of coats needed to get full hiding. This will require two or three medium-wet coats. Allow each coat to flash approximately five minutes and spray each coat slightly wider than the previously applied coat. A premixed mist coat of clear acrylic paint material may be used if desired to melt overspray into the base color. Allow to dry for 20 minutes before applying clear coat. Do not sand base color coat unless it is necessary.
8. If basecoat must be sanded, proceed as follows:
a. Allow base color to dry.
b. Sand with ultra-fine wet-or-dry sandpaper to remove the imperfection(s).
c. Reclean and tack wipe the repair area(s).
d. Apply an additional coat of base color.
e. Allow to dry 20 minutes before applying the clear coat.
9A. Polyurethane Enamel Clearcoat
Because of the better durability of polyurethane enamel clear costs as compared to lacquer, it is preferred if shop conditions allow.
CAUTION: There are a number of paint systems available for service use: however, may require additives containing isocyanates. It is essential that all recommendations and warnings listed on the container label for materials selected be followed.
It is mandatory that adequate respiratory protection be worn.
Examples of such protection are: 3-M Models #6984 and #6986 disposable respirators.
Such protection should be worn during the entire painting process. Persons with respiratory problems, or those allergic to isocyantes must not be exposed to isocyanate vapors or spray mist.
a. Following paint manufacturers' label directions, activate the Polyurethan Enamel material. Mix material thoroughly. Pot life of activated mixture is approximately eight (8) hours.
b. Reduce basecoat per label directions. Some activated Polyurethane Enamel materials are ready to spray as packaged under normal conditions. As conditions vary, to enhance flow out and leveling up to 10% more than the specified enamel reducer may be added to the activated mixture. Check the viscosity of the activated mixture with a Zahn #2 Paint Viscosity Cup or its equivalent. Follow the paint manufacturer's labeled recommendations for paint viscosity cup reading.
c. Using 50 lbs. air presure at the gun, spray two medium-wet coats of enamel clear coat mixture. Allow first coat to set-up for 15-20 minutes before applying the second final coat. Clear coat should be applied over the entire panel wherever possible. When no breaklines are present blend all spray applications within the adhesion promoter boundry (Figure 1) .
Clean spray painting equipment with lacquer thinner immediately after use.
Clearcoat
9B. Lacquer Clearcoat
a. Reduce clearcoat 125-150% with an extra-slow drying lacquer thinner to the recommended paint viscosity cup reading of the manufacturer who's paint product you are using.
b. Spray two medium-wet coats of clear at 35-45 lbs. air pressure at the gun. Allow first coat to flash completely before applying the second coat. At least two coats must be used. Additional coats may be applied if designed. If additional leveling is desired a final coat of premixed mist-coat material (clear acrylic and thinner) can be sprayed at 20 lbs. air pressure at the gun. When no breaklines are present, blend all spray applications within adhesion promoter (Figure 1). Allow the repair to dry overnight, then rub out with a light-cutting hand or machine polishing compound.
FLEXIBLE PANEL REPAIR SYSTEM
Procedure - Full Panel
Full panel repairs must be performed, spot repairs are not recommended.
CAUTION: There are a number of flexible paint systems available for service use; however, many require additives containing
isocyanates. It is essential that all recommendations and warnings listed on the container label for materials selected be followed.
It is mandatory that adequate respiratory protection be worn.
Examples of such protection are: 3-M models #6984 and #6986 disposable respirators.
Such protection should be worn during the entire painting process. Persons with respiratory problems, or those allergic to isocyanates must not be exposed to isocyanate vapors or spray mist.
1. Flexible Undercoat Requirements
If the part to be painted is a replacement, it will be factory primed with an elastomeric enamel-based primer. As long as the original primer is not scratched exposing the plastic substrate, all that is required is to solvent clean, sand with #400 paper or a red "Scotch-Brite" pad, reclean and apply elastomeric color.
However, if the plastic substrate is exposed or the part is repaired with flexible filler material, a flexible primer surfacer must be used to provide the filling properties required. This is to prevent a "bull's-eye" condition or highlighting of the bare substrate or filler repair after color is applied.
Prepare flexible primer surfacer as follows:
a. Clean the entire part with a wax, grease and silicone removing solvent applied with a water dampened cloth. Wipe dry.
NOTE: The step above begins to prepare the entire part for color coats. Spot repair is not recommended because dry spray at the blend area of applied elastomeric color does not "wet out" satisfactorily.
b. Featheredge the scuff or filler repair with #320 sandpaper, blow off dust and tack wipe.
c. Mix and apply four medium dry coats of flexible primer surfacer. Follow manufacturer's instructions for specific mix ratios and additives.
NOTE: Use a fast evaporating thinner as recomended to reduce the primer-surfacer and do not apply excessively wet coats. Bare flexible plastic surface and/or flexible filler materials have a tendency to swell from thinner absorption, resulting in a visible or "highlighted" repair.
d. Allow to dry at least one hour and block sand with #400 sandpaper. Sand the entire part with #400 sandpaper or red "Scotch-Brite" pad to remove all gloss in preparation for color application.
When paints are modified with a flex additive, the possibility of mixture "pot life" exists; therefore, spray equipment should be emptied and flushed immediately after use.
2. Body Color With Flexible Additive Systems
There are several flexible topcoat systems available for the painter's selections; in most cases, it is a matter of personal preference. Basecoat/clearcoat material can be either enamel or lacquer-based.
Some manufacturers do not recommend the use of flex additives in their basecolor material, but do recommend its use for their lacquer clear coat.
a. Thoroughly sand the entire part with #400 sandpaper or red "Scotch-Brite" pad to remove all gloss. Reclean.
b. Mix the base color, flexible additive, if recommended, and thinner. Follow manufacturer's label instructions.
c. Apply a sufficient number of coats to achieve complete hiding and color match. Allow flash time between coats.
d. Allow the base color coat to dry 30-60 minutes before applying the clear coat. Do not sand the base coat before applying the clear coat.
NOTE: If sanding of the base coat is necessary to remove imperfections, such as dirt or sags, sand with #400 grit or finer sandpaper, reclean the area(s). Apply one additional coat of base material and let dry.
3. Clear Coat Application
a. Mix and reduce clear coat (lacquer or enamel) material as per label instructions.
NOTE: Use flex additive if recommended by paint source.
b. Strain the mixture and apply 2-3 coats with 35-40 lbs. air pressure at the gun.
c. Allow each coat to flash completely before applying the next coat. Allow at least 4 hours air dry time or force dry for 30 minutes with a heat lamp at 180~ Fahrenheit before putting into service.
NOTE: Compounding is not necessary when a flexible additive is used in the top coat paint material. The mixture will dry with acceptable gloss.
Compounding dulls the gloss of elastomeric finishes causing a flat appearance. The finish cannot be brought back to the same gloss level without applying more paint.
1985 "C" PAINT SUPPLIES STOCK NUMBER
ACME ROGERS
PPG RINSHED SHERWIN MARTIN SENOUR
PAINT CODE DUPONT DITZLER MASON WILLIAMS LACQUER ENAMEL
13 B8402 3661 A14050F 33494 30-5264 99-5725
21 B8404 3660 A14052 33495 30-5265 99-5726
24 B8408 3674 A14053F 33915 30-5306 99-5777
28 B8405 3662 A14055F 34003 30-5325 99-5796
39 B8474 3663 A14057 33754 30-5294 99-5758
40 B8469 3680 A13570 33755 30-5295 99-5759
41 99 9300 A13572 33756 30-5296 99-5760
44 B8407 3664 A14060D 33496 20-5266 99-5727
68 B8406 3665 A14062G 34054 30-5326 99-5797
72 B8401 3666 A14065V 33935 30-5312 99-5780
84 B8403 3667 A14066D 33936 30-5313 99-5824
89 B8400 3683 A14076F 34329 30-5355 99-5824
96 B8412 3670 A14068D 33938 30-5334 99-5783
Prime repair area.
Wet sand area to be primed and color coated with 400 grit or finer.
Wet sand with 600 grit or finer or hand compound (follow manufactures'
recommendations)..
Apply adhesion promoter over entire panel and blend a minimum of 4-6" into adjacent
area.
Apply basecoat per label directions.
Apply clearcoat over entire panel and blend into adjacent area within adhesion promoter.
Prime repair area.
Wet sand area to be primed and color coated with 400 grit or finer.
Wet sand entire area to be clear coated with 600 grit or finer or hand
compound (follow manufactures' recomendations).
Apply an adhesion promoter over entire area to be color coated and clear
coated.
Apply base color coat over repair area only as per label directions.
Apply clear coat over entire panel as per label directions.