Body Repair - Filling and Painting

Before performing the work described in this section, read the sections describing repair of dents, scratches and corrosion.

There are many types of body filler; however, the best are polymerizing compounds supplied in kits containing a can of filler and a tube of hardener. A wide, flexible plastic or nylon spreader with smooth, well-finished edges is also required for the final finishing of the filled surface.

Mix a small amount of body filler on a clean piece of cardboard or plywood, carefully observing the proportions of filler and hardener specified by the manufacturer, otherwise the filler will harden too quickly or not at all. Using the spreader, apply the filler to the repair area and shape it to obtain the required surface. When the contour of the filled surface is close to the required shape, take a break, otherwise the filler will begin to stick to the spreader. Continue adding thin layers of filler every twenty minutes until the filler level is flush with the surrounding metal.

After the filler has hardened, remove the excess using a metal plate or a file. Continue finishing with abrasive paper of progressively finer grit, starting with 40-grit and ending with 400-grit waterproof paper. Always wrap the abrasive paper around a flat rubber block, cork block, or wooden block; otherwise the filler surface will not be smooth. While sanding the filler surface, periodically wet the abrasive paper with water. The operation is complete when a ring of bare metal appears around the dent, which in turn is surrounded by sound paint. Rinse the repair area with clean water to remove all sanding residue.

Spray a thin coat of primer over the repair area. It will reveal any defects in the filled surface. Correct these defects with freshly mixed filler and sand again with abrasive paper. Repeat this procedure until you are satisfied with the quality of the repaired surface. Rinse the surface with water and allow it to dry completely.

The repair area is now ready for the final operation: painting. Paint spraying must be carried out in a warm, dry, draft-free but ventilated area. These conditions can be created artificially if you have a large enclosed workspace, but if you have to work outdoors, you must choose the day for work very carefully. If you are working indoors, dampen the floor in the painting area. This will help dust in the air settle. If you are going to paint only one body panel, mask the remaining panels; this will help reduce the contrast caused by slight differences in paint color. Body trim (chrome strips, door handles, etc.) must also be masked. Use masking tape and several layers of newspaper for this.

Before starting to paint, shake the aerosol thoroughly and practice spraying on something away from the vehicle until you have acquired sufficient skill. Apply a thick coat of primer over the repair area; however, the thickness should be built up by applying several thin coats rather than one thick coat. Using 400-grit waterproof abrasive paper, sand off all unevenness in the primer. When performing this operation, thoroughly wet the work area with water and periodically rinse the abrasive paper. Allow the primer to dry before applying paint.

Spray a thin coat of paint, starting from the center of the surface to be painted, then smoothly move the spray from one edge to the other so that it overlaps approximately 50 mm of the existing paint. Apply the next coat after a short interval. Build up the required paint thickness by applying several thin coats. Unmask the covered body parts approximately 10 to 15 minutes after applying the last coat.

Allow the new paint to cure for at least two weeks, then level the painted area using polishing compound. After this, apply a protective wax coating.