Most late model vehicles have either a smooth anti-chip (gravel guard) material or the more familiar textured type applied to the lower front fenders, rocker panels and quarter panels.
In the case of smooth anti-chip, because of its smooth appearance, it is very difficult to detect.
One method of detecting its presence is to check the film build in the areas that require protection (see Figure 1). Normal unprotected exterior finishes have a total film build between 3.0 and 4.0 mils while protected areas have a range of 5.0 to 11.0 mils.
When repairing existing anti-chip or adding anti-chip material where there was none, the following guides will aid in achieving either a smooth or textured finish. In any case, manufacturer's label directions should be read prior to application.
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.