The rocker panels on a 1999 Silverado truck are exposed to such debris as mud, water, snow and salt from the road. All of these things contribute to accelerate the damage rust can cause on metal surfaces. Rust can begin in a small section of the rocker panel and quickly spread along the surface, creating surface rust. The next step is rusting the rocker panels completely. Once this happens, they cannot be repaired and must be replaced. Repair the rocker panel rust for a 1999 Silverado using materials from an auto parts store and avoid having to remove and weld new ones in place.
Use a stiff bristled brush to brush away any loose surface rust from the rocker panel. The loose pieces of rust can end up flaking off underneath the paint, causing chips and cracks in the paint and exposing the metal, allowing new rust to form.
Sand the surface with 180-grit sandpaper. This can be done by hand or by using a dual action sander. Sand until the surface is smooth. It's okay to leave some rust on the rocker panels as it will be removed in the next step.
Spray the rusted area with rust repair spray. This spray turns the rust black in color and stops the rust from spreading. Hold the can 8 inches from the surface and spray a thick coat over any area of the rocker panel that has rust. Allow the spray to dry for one hour.
Use a squeegee to apply a layer of body filler over any areas that are lower than the surrounding surface of the rocker panel. Allow the filler do try for 1 hour.
Sand the filler with 120-grit sandpaper until it is smooth and level with the surrounding surface.
Cover the area with a coat of primer until the filler can no longer be seen. Hold the can six to eight inches from the surface. Let the primer dry for 30 minutes.
Cover the primer area with three to four coats of paint. Use thin coats so there are no runs in the paint. Hold the can six to eight inches from the surface of the Silverado. Wait five minutes between each coat. Wait four to six hours before handling the area.
