Repair of minor body scratches
If only the paint is scratched, the repair is very simple. Wipe the damaged area with a special compound to remove peeling paint and clean the surrounding areas of protective polish, then rinse it with clean water.
Paint over the scratch using a thin brush; continue to apply thin coats of paint until the damaged area is the same thickness as the surrounding layer. Let the new paint dry for at least two weeks, then buff the scratched area and wax it up.
If the scratch has damaged the metal of the body, causing rust, use another repair method. Remove the rust from the bottom of the scratch with a penknife, then apply a primer to prevent future rust formation. Using a rubber or nylon applicator, fill the scratch with filler. If necessary, the filler can be mixed with a special cellulose-based compound to form a very fine paste, ideal for filling narrow scratches. Before the filler in the scratch hardens, lightly run a cotton swab moistened with cellulose compound over the surface of the filler until its level is just below the surrounding paint layer. The scratch can now be painted as described earlier in this Chapter.
Dent Repair
With a deep dent, the first task is to to level the surface as close to the original shape as possible. It makes no sense to try to restore the original shape completely, since the metal in the damaged area «stretched out» and cannot be completely returned to the original contour. It is better to leave a dent depth of approximately 3 mm. If the dent is superficial, this should not be done at all. If the back of the dent is accessible, it can be leveled out by gently tapping with a wooden or plastic straightening hammer. While doing this, place a block of wood on the outside of the dent to dampen the excessive force of impacts and thus prevent the body from bulging.
If the dent is in a two-ply body section, or if the reverse side of the dent is otherwise inaccessible, use a different technique. Drill several small holes in the damaged area, primarily at the bottom of the dent. Screw long self-tapping screws into the holes so that you get a good grip on the metal. The dent can now be straightened with pliers.
The next stage of repair is the removal of paint from the damaged area. At the same time, it is necessary to capture the surrounding undamaged area by about 2.5 cm. The paint can be easily removed with a metal brush or an emery wheel mounted on an electric drill. This can also be done manually with sandpaper. To ensure good adhesion to the filler, scratch the surface of the metal with a screwdriver or file shaft, or alternatively drill a few small holes in it.
To complete the repair, see subchapter «Priming and painting».
Repair of holes and rusted through surfaces of the body
Remove all paint from the damaged area and 2.5 cm around, using a wire brush or emery wheel, mounted on a power drill, or using sandpaper by hand. Assess the severity of the corrosion and decide whether to replace or repair the panel. New body panels are not as expensive as many people think, and it is better to install a new panel than to try to repair large corroded areas.
Remove the components installed on the damaged area, with the exception of those that will help restore the original shape of the body (e.g. headlight frames, etc.). Then cut out any damaged or rusty metal and trim the edges of the hole inwards.
Clean the surface of the edges from rust. Coat the damaged area with anti-rust paint on both sides, if possible.
Seal the hole with aluminum or plastic mesh or aluminum tape.
Aluminum or plastic mesh or fiberglass is probably the best material for patching large holes. Cut out a patch of the appropriate size and shape and place it under the hole. Fix its edges with a few drops of filler.
For small or narrow holes, it is better to use aluminum tape. Cut the patch to the appropriate size and shape, then remove the backing paper (if used) and stick the tape on the hole. Multiple layers of tape can be applied if one layer is not thick enough. Run along the edges of the tape with the handle of a screwdriver, ensuring that the tape is securely attached to the metal.
Body repair - priming and painting
Before taking the actions described in this chapter, see the chapters on repair of dents, deep scratches and holes.
There are many types of primers. Choose a kit that includes a can of filler and a tube of resin hardener that can be used directly from the tube. Besides. You will need a wide flexible plastic or nylon applicator.
Mix a small amount of filler and hardener on a piece of clean cardboard or board, carefully measuring out the hardener (follow the manufacturer's instructions), otherwise the filler will harden too quickly or too slowly. using the applicator. Apply the filler to the prepared area and level the surface with the applicator. Do not level the filler for too long, over time it becomes sticky and sticks to the applicator. At 20-minute intervals, continue to apply thin coats of filler until it is level with the metal of the surrounding bodywork.
If the filler has hardened, the excess can be removed with a file. Then the surface should be treated with several grades of sandpaper, starting with coarser and moving on to fine-grained skins. When doing this, wrap the skin around a flat bar to achieve a flat surface. Periodically moisten the finest sandpaper so that the surface it sands becomes completely smooth.
At this stage «dent» should be surrounded by a ring of bare metal, surrounded in turn by a ring of good color. Rinse the repaired area with clean water to remove any sandpaper residue.
Spray a small amount of primer onto the surface to be treated - this will reveal any defects in the surface of the filler. Eliminate these defects with a new layer of primer or filler and sand the surface again with sandpaper. Mix the filler with a special cellulose-based compound to form a fine paste, ideal for filling small crevices. Repeat this procedure until you are sure the surface is perfect. Rinse the repair area with clean water and let it dry completely.
The repair area is now ready to be painted. Spraying should be carried out in warm, dry and calm weather or in a dust-free area. If you are working indoors, spray the floor with water to settle the dust. If the area to be repaired is limited to one body panel, cover the surrounding panels to help minimize the effect of slight paint mismatch. Body Mounted Components (e.g. chrome strips, door handles, etc.), also needs to be covered. Use duct tape and several layers of newsprint for this.
Before spraying, shake the paint bottle well, then practice the painting technique on a test surface (old tin, etc.). Cover the area to be repaired with a thick coat of primer, consisting of successive thin coats, and allow it to dry thoroughly. Sand the surface of the primer with the finest sandpaper, wetting it periodically during work, rinse the sanded surface and let it dry again.
Spray the paint, applying it in thin layers. Start spraying in the center of the area to be painted, then work in a circular motion to the edges and move about 5 cm. After 10-15 minutes after spraying, remove the coating from the surrounding panels.
Let the new paint dry for at least two weeks, then use a special polish to blend the edges with the old paint. Finally, cover the repair area with wax.
Plastic components
With the increase in the number of plastic body components used by manufacturers (bumpers, spoilers and sometimes main body panels), repair them. serious damage becomes a matter of choice; entrust this work to a specialist or replace the component. Self-repair of such damage is not possible, due to the high cost of equipment and materials required for such repairs. First, a groove is made along the crack line, then a special plastic rod is placed in it and the crack is welded, melting the rod with a hot air gun. The excess plastic filler is then removed and the resulting surface is sanded. It's important to use the correct type of plastic, as case components can be made from many different types of plastic.
Less serious damage (abrasion, small cracks, etc.) can be repaired by the owner with a two part epoxy. Mixed in equal proportions, it is applied similarly to the filler used on metal body panels. The resin usually cures in 20-30 minutes, after which the repair area is ready for sanding and painting.
If the owner replaces or repairs the component himself, he will face the problem of choosing a paint that is compatible with this type of plastic, because. There is no universal paint suitable for all types of plastics. Therefore, to select the desired paint, you will have to contact the dealer. However, it is now possible to purchase a kit for painting plastic parts of the body, consisting of filler, primer and paint. The kit is usually accompanied by instructions, but the main method of use is to repair damage, dry (up to 30 minutes), subsequent application of the primer, which is dried for an hour before painting. As a result, the color is chosen correctly, and the paint has the properties of flexible plastic or rubber.