INDUSTRIAL FALLOUT-PAINT DAM. FINESSE TYPE REPAIRS

SUBJECT: CORRECTING DAMAGE TO BASE/CLEAR COAT CAUSED BY INDUSTRIAL FALLOUT/RAIL DUST

MODELS AFFECTED: 1985-1993 DE VILLES, FLEETWOODS, 60 SPECIALS 1986-1993 ELDORADOS AND SEVILLES 1987-1993 ALLANTES 1991-1993 BROUGHAMS/FLEETWOODS

This bulletin should be used in conjunction with DSIB 91-I-43A "Importance of Checking Clear Coat Thickness Before and After Paint Finesse Operations" and with Service bulletin T-91-84 "Polishing Techniques for Base Coat/Clear Coat Paint".

NOTE: It is not recommended that rail dust remover containing oxalic acid be used as a routine part of the new car preparation procedure.

Rail dust is a term applied to iron particles deposited on the surfaces of a vehicle by the friction of the train's wheels passing over the rails. Other sources of industrial fallout can have similar metallic residue on unprotected surfaces of the vehicle.

This dust can lie on the painted surface or become embedded in the film build. This contamination can give the painted surface a gritty texture and rust-colored spots may appear in the paint.

To prevent industrial fallout damage customers should be urged to wash and dry their vehicles frequently. When not in use, the vehicle should be parked in a garage or protected by a quality car cover.

CAUTION:

Rail dust remover (oxalic acid) is an acidic substance which breaks down the iron particles embedded in the finish. When working with this material, follow the manufacturer's directions closely. Use the necessary safety equipment including gloves and goggles. Material may require special handling and disposal.

Excessive concentrations of these materials have been demonstrated to cause corrosion and staining of the chrome-plated moldings on 1992-1993 Eldorado and Seville carlines. Improper application may also affect the long-term durability of the painted surfaces.

To remove metallic/rail dust use the following procedure:

1. Select a cool or shaded work area.

2. Gently wash and dry the vehicle being careful not to scratch the clear coat by rubbing loosened metal particles across the surface. Clean the affected area with a wax and grease remover.

3. Rinse the vehicle thoroughly.

4. Soak several strips of cloth in a container of rail dust remover solution (industrial fallout remover #5029 Zep Corporation, or equivalent) and lay them across the contaminated surfaces. Allow these cloths to remain in place for 20 minutes periodically spraying them with water to keep them moist.

NOTE: Do not allow the solution to dry as paint damage will occur.

5. Remove the cloths and rinse the area thoroughly with a mixture of cold water and baking soda (one tablespoon of baking soda to one quart of water ratio).

NOTE: After each application of the rail dust solution it is important to neutralize the acid left on the surfaces of the car to protect the long-term durability of the paint finish. All surfaces (painted and non-painted) which have been exposed to oxalic acid must be neutralized in this manner. Oxalic acid is corrosive to stainless steel and anodized aluminum parts. Be sure to rinse underhood components thoroughly if oxalic acid was used on the hood.

6. Inspect the repair area to ensure the dust has been removed. Use both touch (feeling for bumpy surface) and sight (magnifying glass) during evaluation. If some particles are still present, steps 4 through 6 can be repeated three times. If metal filings are embedded in the base coat, a repaint of the panel is required. If all particles have been removed, proceed to step 8. If some particles remain in the clear coat after three rail dust solution applications, proceed to step 7.

7. Select a test area and wet sand with American ultra fine 1500 grit to 2000 grit sandpaper to dislodge remaining particles in the clear coat and to smooth out the pits caused by the dust particles.

8. Buff with 3M Finesse-It II or equivalent to restore the luster of the paint film.

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.