Sand away the paint around the dent or damaged area. A heavy grit sandpaper will work well, though a drill with a wire wheel bit may produce faster results, especially on large dents. Continue sanding until all paint and primer within the dent and on the surrounding surface have been removed.
Purchase an auto body filler from an automotive supply store. This product is commonly referred to as Bondo, after a popular brand name version.
Mix your auto body filler on a piece of scrap wood or cardboard. The filler consists of both a resin and hardener, which should be mixed according to the instructions on the package. Blend these materials thoroughly using your putty knife.
Spread a thin layer of filler across the dent and the surrounding area, using your putty knife. Wait a few minutes for this first layer to start to set, then apply a second layer. Continue this process of applying thin layers until the patched area is slightly higher than the surface around it.
Wait an hour for the filler to dry before proceeding. Use a fine-grit sandpaper to sand the area smooth. Work slowly to avoid over-sanding. Try to blend the patched area into the surrounding surface in terms of texture and "height."
Use a vacuum with a hose attachment to clean away all sanding dust from the patched area. Follow up with a tack cloth to remove small dust particles that may be remaining.
Prime the patch with an acrylic latex primer. Once the primer has dried, paint the repaired area with an acrylic latex paint to match the rest of the door. If you've repaired a large area, you may have to paint the entire door to achieve a uniform finish.
Things You Will Need
- Sand paper
- Tack cloth
- Bondo (auto body filler)
- Putty knife
- Acrylic latex primer
- Latex paint
- Paint brush
- Consider covering dents and damage at the bottom of your door using a metal kickplate. These units screw into the door, offering protection as well as an attractive finish.