CLEARCOAT PAINTING/REPAIR PROCEDURES(STRIPPING REFINISH)

Model and Year: 1984/87 CORVETTE

This bulletin includes service procedures for stripping and refinishing a subject vehicle that has a peeling clearcoat. For refinishing without clearcoat peeling problems, skip the clearcoat stripping procedure.

When repairs to the clearcoat are required the complete vehicle should be washed with a mild detergent and water to remove any water soluble contaminants. Then wash with a wax and grease removing solvent to remove any nonwater soluble contaminants such as road tar, waxes, grease and silicones. This procedure, performed prior to sanding, prevents these substances from being ground into the original finish. Repairs to the colorcoat do not require pre-washing.

NOTICE: WHEN PERFORMING A REFINISH OPERATION ON THIS VEHICLE, IT IS RECOMMENDED THAT ITEMS WHICH ARE DIFFICULT TO MASK; SUCH AS DOOR HANDLES, MIRRORS, MOLDINGS, ETC.,SHOULD BE PULLED LOOSE, OR REMOVED. THIS INSURES A QUALITY REPAIR.

CLEARCOAT STRIPPING PROCEDURE

The affected panel should be stripped. There are currently no chemical strippers that will remove the paint finish from these panels without eating into the fiberglass. One method available is stripping with an oscillating sander with a sandpaper grit of #80 to #100. When stripping the panels, it is important to keep the pad of the sander flat to prevent digging holes in the fiberglass. All existing clearcoat must be removed prior to starting finish operations.

An optional method of stripping is plastic media blasting (see list of plastic media blasting sources at the end of this bulletin). Plastic media blasting is much like sand blasting but uses plastic particles as a media and much lower air pressure.

FINISH OPERATIONS

After sanding remove sanding residue by blowing off and wiping the vehicle and/or panels with wax and grease remover.

Apply primer surfacer to all base SMC fiberglass panels. Keep primer surfacer within damaged areas. Let primer dry according to manufacturer's label.

A high quality urethane or epoxy primer is recommended.

Block sand to eliminate high and low spots caused by the previous sanding process using #240 grit wet-or-dry sandpaper. Remove sanding residue and reclean the vehicle and/or panels using a wax and grease remover. Wipe down one panel to locate any waves or imperfections. By keeping the panel wet, waves and imperfections will be highlighted. If the waves are at an unacceptable level, prime and reblock sand.

NOTICE: DARKER COLORS WILL SHOW WAVES MORE. TAKE TIME TO INSURE STRAIGHTNESS BEFORE CONTINUING.

When all panels are straight, finish sand with a #400 wet-or-dry sandpaper.

Reclean the panels with wax and grease remover then tack wipe.

NOTICE: DEPENDING ON THE TYPE OF REFINISH SYSTEM USED, AN ADHESION PROMOTER MAY BE NECESSARY. THIS SHOULD BE USED ACCORDING TO MANUFACTURER'S LABEL.

It is recommended that an enamel basecoat/clearcoat or urethane system be used to refinish because of its superior durability and resistance to chemical and atmospheric contamination. This offers the closest refinish system to factory paint, which is a high solids basecoat/clearcoat enamel. An alternative system when dirt is a problem would be a base lacquer with a clear enamel or urethane topcoat. Depending on the paint systems used, a flex agent may be required when painting flexible parts such as fascias and rocker panels. A sealer may be required depending on the paint system used.

NOTICE: WHEN USING ANY REFINISH SYSTEM, IT IS IMPORTANT TO USE THE COMPONENTS AND PRODUCTS RECOMMENDED, AS THEIR CHEMISTRIES WERE DESIGNED TO WORK TOGETHER.

CAUTION:

THERE ARE A NUMBER OF 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. USE A NIIOSH- APPROVED CHARCOAL OR AIR-SUPPLIED RESPIRATOR AS RECOMMENDED IN THE LABEL DIRECTIONS OF THE ACTIVATING MATERIAL BEING USED.

Refer to the Labor Time Guide, March 15, 1988 revision for panel labor operation numbers and repair times.

PLASTIC MEDIA BLASTING SOURCES

MBI Industries Paint Removal Service Inc. 33880 Groesbeck Hwy. P.O. Box 28312 Fraser, MI 48026 Atlanta, GA 30358 (313) 792-5790 Bill Cordray Bob Schaeffer

Superior Stripping The Derrick Company Columbus, OH 4560 Kellogg Avenue (614) 475-0555 Cincinnati, OH 45226 (513) 321-8122 Joel Perry

Carnes Plasti-Tech Inc. Sumter, SC The Strip Shop (803) 494-3300 4354 Broad Street Extn. Sumter, SC 29154 (803) 494-3006 Bob Carnes

Marvin Phelps Master-Blasters Inc. Covingron, KY 312A W. Taylor (606) 485-7858 Griffin, GA 30223 (404) 227-8793 wayne McKemie Hi-Tech Stripping Co. 381 Crossen Avenue Elk Grove Village, IL 60007 (312) 228-1870 Gregg Straley

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.