Driving some 1985-92 trucks on gravel or dirt roads may result in exterior stone chips. A "stone chip" can be defined as an area that has been stopped of the topcoat due to contact with gravel or other similar materials.
Some GMC Truck paint finishes contain a anti-stone chip protector on the lower exterior surfaces. The anti-stone chip material is applied to the lower fenders, the complete rocker panels, lower doors, quarter panel dogleg, and to the lower rear of the quarter panel behind the wheel. For appearance reasons the anti-stone chip material will usually end at a body characteristic line.
Anti-Stone Chip Protector can be purchased locally and applied to areas of a vehicle prone to stone chips. Upon application, the anti-stone chip protec- tor may also provide resistance to water, oil, etc. and has excellent corrosion characteristics. Anti-Chip Spot Repair
1. Wash the entire vehicle with water and a mild detergent soap, rinse thoroughly and let dry.
2. Clean the vehicle with a precleaning solvent to remove oils and dirts.
3. Sand the repair area and feather edge using an appropriate sand paper as required. Extend the feather edge 1 1/2 to two inches out to prevent a "bulls eye" from appearing.
4. Prepare the repair area and spray any bare metal areas with epoxy primer or self-etch prime or equivalent.
5. Apply 1-2 coats of primer over the bare metal areas. Allow 15-20 minutes to dry before anti-stone chip protector is applied.
6. Apply one coat of anti-stone chip protector as required. (See Anti-Stone Chip Protector Information For Suppliers)
Refer to the supplier specifications provided with the material for proper application techniques.
7. Allow approximately 2 hrs of drying time as required.
8. Anti-stone chip protector can be topcoated with a single stage or base/clear coat urethane finish or can be left as the final coat.
Panel Repair
Procedures for repairing a panel are the same as repairing a spot repair except for step 3. It may be easier for the painter to sand the entire panel. This will allow the painter to apply a more uniform application when the anti-stone chip protector is applied.
Anti-Stone Chip Protector Supplier Information
Anti-Stone Chip protector can be obtained locally from the following suppliers.
Supplier Part Number -------- ----------- BASF Glassohyd 1109-1240/6
Dupont 123-S Vinyl 310S/330S
Sherwin Williams Vinyl Gravel Guard G1 W 295
PPG Roadguard DX 54
3M Rocker Panel Spray (Lt. Tan) 051131-05910
3M Rocker Panel Spray (Clear) 051131-05911
"We believe these sources and their product to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any product from these firms or for any such items which may be available from other sources."
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.