PAINT STRIPPING INFORMATION AND PROCEDURES

Models Affected: All General Motors Vehicles

The corrosion protection provided by the factory metal preparation and primer cannot be duplicated in a body shop and therefore, the finish should not be stripped down to bare metal unless absolutely necessary. This is particularly true if the primer was applied by electrodeposition (ELPO), which greatly enhances the corrosion resistance of the vehicle.

Only strip the areas that require stripping. If only part of the roof needs to be stripped, then strip only that part of the roof, not the whole vehicle.

Some of the conditions that require stripping down to bare metal are:

1) rust 2) body work 3) cracked primer

The following are conditions that require only the topcoat to be stripped leaving the factory primer intact:

1) cracked topcoat 2) peeling paint 3) excessive film build-up

Checking the Condition of the Primer

If you are not sure if only the topcoat or the complete finish needs to be stripped, then use lacquer removing solvent to remove the lacquer topcoat from a small area. Clean this area with a rag soaked in a slow reducer. Dry the area and examine it with a magnifying glass. If cracks or pinholes are present in the primer, then strip only the defective areas to bare metal, otherwise only strip the lacquer topcoat.

Stripping the Color Topcoat

All Buicks are finished in acrylic lacquer with the exception of 1982 and 1983 Centurys built at Oklahoma City which are finished in acrylic enamel. To remove a lacquer topcoat without disturbing the factory primer, use a lacquer removing solvent (feather edger) or an acrylic lacquer paint remover such as Ditzler's DX525 or equivalent.

I. Lacquer Removing Solvent (Feather Edger)

Soak a rag with the solvent and rub the finish until all the topcoat color is removed. Have many rags on hand, keep cloths wet with solvent and turn over frequently to aid in removing finish.

II. Lacquer Paint Remover (i. e. Ditzler's DX525)

A lacquer paint remover will strip lacquer and air dry enamel finishes but will not touch factory baked enamels and primers.

1. Wear rubber gloves and protective glasses and use in a well ventilated area.

2. Double mask all areas to be protected. Do not allow stripper to come in contact with fiberglass, urethane or plastic parts.

3. Brush on one heavy coat of stripper and allow to stand for about 15 minutes.

4. Using a rubber squeegee, simply wipe the old finish off.

5. Remove any remaining residue with lacquer solvent. (Do not use water to wash off since DX525 is not water soluable).

Stripping to Metal

I. Mechanical Method

(A) Lacquer Finish

1. Remove lacquer topcoat with lacquer removing solvent or acrylic lacquer paint remover as previously described. (This is necessary to prevent the grinding disc from getting clogged with lacquer, which melts when it gets hot from friction).

2. Use a No. 24 grit sanding disc to grind off primer down to bare metal.

3. Finish up with a No. 50 grit disc to remove coarse sand scratches.

(B) Enamel Finish

1. Use a No. 24 grit sanding disc to grind off finish to bare metal. (Enamel does not clog the grinding disc like lacquer does).

2. Finish up with a No. 50 grit disc to remove coarse sand scratches.

II. Chemical Method

The following are directions for use of Ditzler's DX-587 fast acting paint stripper. It will remove alkyd, epoxy, acrylic, acrylic urethane and urethane finished as well as ELPO primer down to bare metal. Similar products are available from other manufacturers.

1. Wear rubber gloves and protective glasses and use in a well ventilated area. The use of a charcoal filter mask is recommended.

2. Double mask all areas to be protected. Do not use paint stripper on fiberglass panels, flexible urethane parts, plastic parts or mouldings.

3. Stir or agitate before using.

4. Apply the stripper with a paint brush or law pressure spray unit. Once the stripper is on the finish, do not agitate it as this will allow the solvents to escape from the stripper.

5. Let the stripper stand for 15 minutes to 1 hour or until the paint softens and lifts.

6. Remove old finish with a nylon squeegee or hose off with a high pressure hose.

7. Blow the surface dry and wipe with a rag soaked in silicone and wax remover. (Paint stripper contains wax to hold it against metal panel and seal solvents in).

Mechanical vs. Chemical Stripping

Mechanical stripping is fastest for a small area such as part of a door or fender. Mechanical stripping is also good in an area where the chemical stripper may damage the part or a part nearby.

Chemical stripping is quick and easy for a vehicle requiring complete stripping, although areas that need protecting must be double masked first. Chemical stripping is also very good when stripping a complete panel such as a hood or door that can be removed from the vehicle.

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.