Contents: Repair of minor body scratches ⬇ Dent repair ⬇ Repair of holes and rusted-through…⬇ Body repair - priming and painting ⬇ Plastic components ⬇
Note: For more detailed information on body repair, please refer to a special book called "Body Repair Guide". This publication includes detailed information on such aspects as treating corroded areas, painting, repairing fiberglass components, as well as more complex body repairs that require welding and panel straightening.
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 loose paint and clean the adjacent areas from the protective polish, then rinse it with clean water.
Paint over the scratch using a thin brush; continue applying thin coats of paint until the damaged area is even with the surrounding paint. Allow the new paint to dry for at least two weeks, then buff the scratched area and wax it.
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 pocket knife, then apply a primer to prevent future rust. 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 make a very thin paste, ideal for filling narrow scratches. Before the filler in the scratch hardens, lightly rub a cotton swab soaked in cellulose compound over the surface of the filler so that its level is just below the surrounding paint. The scratch can now be painted as described earlier in this Chapter.
Dent repair
In the case of a deep dent, the first task is to level the surface as close to the original shape as possible. There is no point in trying to restore the original shape completely, since the metal in the damaged area has "stretched" and cannot be completely returned to the original contour. It is better to leave the dent depth at about 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 by gently tapping with a wooden or plastic straightening hammer. When doing this, apply a wooden block to the outside of the dent to absorb excessive force from the blows and thus prevent the body from forming bulges.
If the dent is in a two-layer section of the body or its reverse side is otherwise inaccessible, use a different technique. Drill several small holes in the damaged area, primarily at the bottom of the dent. Screw long screws into the holes so that you get a good grip on the metal. Now the dent can be straightened out with pliers.
The next stage of the repair is to remove the paint from the damaged area. This should include the surrounding undamaged area of approximately 2.5 cm. The paint can be easily removed using a wire brush or an emery wheel mounted on an electric drill. This can also be done manually using sandpaper. To ensure good adhesion of the filler, scratch the surface of the metal with a screwdriver or a file rod, or, alternatively, drill several small holes in it.
To complete the repair, see the sub-chapter "Priming and painting".
Repair of holes and rusted-through surfaces of the body
Remove all paint from the damaged area and for an inch around it using a wire brush or sanding wheel attached to a power drill, or sand 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 areas of corrosion.
Remove components installed in the damaged area, except for those that will help restore the original shape of the body (for example, headlight frames, etc.). Then cut out any damaged or rusty metal and trim the edges of the hole inward.
Clean the surface of the edges from rust. Cover the damaged area with anti-corrosion 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 a patch of the appropriate size and shape and place it under the hole. Secure 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 paper backing (if used) and apply the tape to the hole. You can apply multiple layers of tape if one layer is not thick enough. Run the screwdriver handle along the edges of the tape, ensuring that the tape is securely attached to the metal.
Body repair - priming and painting
Before taking the actions described in this Chapter, please refer to 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. You will also 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 layers of filler until its level is equal to the metal of the surrounding body part.
If the filler has hardened, the excess can be removed with a file. The surface should then be treated with several grades of sandpaper, starting with the coarser and moving on to fine-grained ones. In doing so, wrap the sandpaper around a flat block to achieve a flat surface. Periodically wet the finest sandpaper so that the surface being sanded becomes completely smooth.
At this stage the "dent" should be surrounded by a ring of bare metal, which in turn is surrounded by a ring of good paint. Rinse the repair 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 filler surface. 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 depressions. Repeat this procedure until you are sure the surface is perfect. Rinse the repair area with clean water and allow it to dry completely.
The repair area is now ready to be painted. Spray paint in warm, dry and windless weather or in a dust-free room. If you are working indoors, spray the floor with water to settle the dust. If the repair area is limited to one body panel, cover the surrounding panels to help minimize the effect of minor paint color mismatches. Body-Mounted Components (for example chrome strips, door handles, etc.), also needs to be covered. Use adhesive tape and several layers of newspaper for this.
Before spraying, shake the paint bottle well, then practice the painting technique on a test surface (old tin, etc.). Cover the repair area with a thick coat of primer, consisting of successively applied thin layers, and let it dry thoroughly. Sand the surface of the primer with the finest sandpaper, periodically wetting it during work, rinse the sanded surface and let it dry again.
Spray the paint in thin layers. Start spraying in the center of the area to be painted, then move in a circular motion to the edges and go beyond them by about 5 cm. After 10-15 minutes from spraying, remove the coating from the surrounding panels.
Allow the new paint to dry for at least two weeks, then use a special polishing compound to blend its 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), repairing their serious damage becomes a matter of choice; have a specialist do the job or replace the component. It is not possible to repair this type of damage yourself due to the high cost of the 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 by melting the rod with a hot air gun. The excess plastic filler is then removed and the resulting surface is sanded. It is important to use the correct type of plastic, as the body components can be made of different types of plastic.
Less serious injuries (abrasions, small cracks, etc.) can be repaired by the owner himself using a two-part epoxy resin. Mixed in equal parts, it is applied similar to filler used on metal body panels. The resin usually hardens 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, since there is no universal paint suitable for all types of plastic. Therefore, to select the right paint, you will have to contact the dealer. However, it is now possible to purchase a kit for painting plastic body parts, consisting of filler, primer and paint. The kit usually comes with instructions, but the main method of use is to repair the damage, dry (up to 30 minutes), subsequent application of a 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.
