Minor body damage — repair (Audi A4 B5)

Repair of minor body scratches

If the scratch is superficial and does not affect the body metal, the repair is very simple. Wipe the area around the scratch with paint cleaner, or a thin polishing paste to remove traces of wax polish. Rinse the cleaned area with water.

Apply paint to the scratch using a soft brush. Continue applying paint until the scratch is filled. Allow the paint to cure for at least a couple of weeks, then buff the area using a fine polishing compound. Finish with a coat of polish.

If the crack has penetrated to the metal and the metal is rusted, there are several ways to repair it. Remove the rust from the metal by scraping it off with a sharp knife, then apply a coat of anti-corrosion primer to prevent further corrosion. Then, using a rubber or nylon spatula, fill the crack with a filler, diluting it with an appropriate solvent if necessary. Before the filler hardens, wipe the area with a clean cotton rag wrapped around your finger, wet your finger with solvent and quickly smooth out the unevenness. Now, instead of a crack, there will be a small depression, which, after drying, can be painted over using the method described above.

Car body dent repair

When a dent appears on the body, the first task is to pull it out until the part is given a shape as close to the original as possible. Usually, there is little hope of recreating the original shape, since the metal is pulled out. It is enough to straighten the dent to a level below the original by about 3 mm. In cases where the dent is wide and shallow, you can still try to carefully squeeze it out. If the back side of the dent is accessible, you can try to carefully knock it out with a mallet or a hammer with a rubberized or plastic head, starting from the edges to the middle. In this case, support the outer surface of the dent with a piece of wood to absorb the blows of the hammer and prevent the metal from bulging outward.



If the dent is in a part of the body with a double layer of metal, or access from the inside is impossible, use other methods. Drill several small-diameter holes in the dent, in its deepest places. Screw in self-tapping screws. Pull out the dent, grasping the self-tapping screws with pliers.

The next stage of repair is to remove paint from the damaged area and around it by 2-3 cm. This can be done with a wire brush clamped in a drill chuck, or with sandpaper by hand. To complete the surface preparation, use a sharp screwdriver to make grooves on the surface or drill several small holes in the damaged area - this will facilitate the adhesion of the putty to the metal.

Repair rusty holes or deep dents

Remove all paint from the surface to be restored using a round wire brush clamped in the chuck of an electric drill. If this tool is not available, work by hand with sandpaper. After removing the paint, assess the extent of the corrosion and decide whether to replace the entire part (if possible), or repair the damaged area. New body parts are not as expensive as some car owners are mistaken. Replacing and painting them is often cheaper and more durable than restoring a "rusty accordion".

Remove all parts from the damaged area except those that will be necessary to form the surface back to its original condition. Use metal shears or a cutting wheel to remove any hopelessly rusty areas of metal. Bend the edges of the hole inward with a hammer to create a rib of strength for the adhesion of the filler layer.



Remove porous rust from the metal surface with a wire brush. Cover the area around the hole with anti-corrosion primer. If the back side is accessible, cover it with primer as well.

Before filling the hole with putty, it must be plugged somehow. This can be done with an aluminum or plastic mesh, or foil.

For larger holes, the best results are obtained by gluing an aluminum or plastic mesh or fiberglass to the back. Cut the patch to the shape of the hole, slightly smaller, and secure it in the hole with a few drops of putty so that the surface of the patch is below the level of the metal.

For small or very narrow holes, you can use self-adhesive aluminum foil. Unroll a piece from the roll, cut it to the shape and size of the hole, and stick it to the hole. If one layer is not enough, stick another. Rub the edges of the patch with a screwdriver handle so that they press better to the metal.

Body repair - puttying and painting

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

There are many types of putty pastes, the best are polymer compositions, which contain a jar of paste and a tube of hardener in the kit. For work, you will also need a wide flexible plastic or nylon spatula with smooth, well-processed edges for final sealing of the surface.

Prepare some putty on a clean piece of cardboard, plywood or PVC tile, carefully observing the proportions of paste and hardener in accordance with the manufacturer's instructions, otherwise the putty will harden prematurely or never harden. Apply the putty with a spatula to the repaired area and level it so that you get a surface close in shape to the original. Take a break from work so that the putty hardens and does not stick to the spatula. Every twenty minutes, apply new putty until the putty area is leveled with the surface of the undamaged body part.



After the putty has hardened, its excess is removed with a scraper or scraper, or, most often, with sandpaper wrapped around a wooden or rubber block. When sanding the surface, the paper grain is gradually reduced, starting with waterproof paper of class 40 and ending with class 400. During work, the paper is periodically washed in water, if possible, a thin stream of water is supplied directly under the paper during work so that the surface is sanded evenly.

At this stage, a ring of clean metal is formed around the filled dent, which in turn is surrounded by good paint. Rinse the treated area with clean water to remove sanding products.

Apply a thin coat of primer ("developer layer") to the repaired area - it will reveal all defective areas. Remove all defects with a thin coat of filler or pore filler and sand again with sandpaper. This work cannot be finished, it can only be stopped when you are satisfied with the result. Rinse the surface with water and let it dry.

Now the area to be restored is ready for the final stage - painting. Spraying of paint should be done in a warm, dry, ventilated room. If you have to work outside, choose the appropriate weather conditions. If it is possible to use a closed room, wet the floor with water to knock down dust. If you are going to paint only one part, cover the others to smooth out any discrepancies in color. It is also necessary to protect the body from spraying paint - for this, use newspapers and paper "scotch tape".

Before you start painting, shake the aerosol can well, then test the spray on a test surface (for example, on an old can), so that "the hand gets used to it". Cover the repaired area with a thick layer of primer. The thickness of the primer should be achieved in several thin layers, one thicker than the other. The surface is "matted" with fine-grained sandpaper of class 400. When "matting" the surface, wash off the matting products with water, periodically rinsing the sandpaper. Dry the surface before final painting.



Spray the paint with a thin layer, starting from the middle of the surface to be painted, moving the torch from edge to edge, overlapping the edges of the old paint by about 50 mm. After a while (usually 10...15 minutes) apply the next coat of paint. The thickness of the coating should be achieved by applying thin layers multiple times. Remove the covering newspapers no earlier than 10-15 minutes after applying the last coat.

Allow the paint to cure for at least a couple of weeks, then buff with a fine polishing compound and apply a coat of protective polish.

Plastic parts

The use of more and more plastic body parts by car manufacturers (bumpers, spoilers, and in some cases the main body parts) leads to the fact that in case of damage to such parts it is necessary to seek help from a specialist, or replace them with new ones. Carrying out this kind of repair at service stations is associated with expensive equipment. materials and therefore is impossible. The main method of such repair is to first cut a groove along the crack using a cutting wheel, after which the groove is welded with a plastic rod. Excess plastic is removed and the surface is leveled. It is important to use a rod of the same chemical composition as the part being repaired, since different materials are used in the car (polycarbonate, polypropylene, etc.).

Less serious damage to plastic parts can be repaired with a two-component epoxy filler. It is also sometimes used for body repairs. It usually hardens in twenty to thirty minutes, after which it can be sanded and painted.

If the owner decides to repair plastic parts on his own, he will face the problem of finding a suitable paint for plastic, which would be compatible with it not only in color, but also in composition. Until now, it was not possible to use paint for these cases, due to the large variety of plastics used. Conventional paints, generally speaking, do not adhere well to plastics and rubber, but suitable paints can be purchased from dealers. Be that as it may, it is now possible to purchase a plastic repair kit, which contains preliminary and final primers and paint for the final coating. Full instructions are included with them, but the idea is to first apply a preliminary primer, then let it dry for half an hour. Then the main primer is applied - an hour of drying - and the special paint is applied. The result is color matching, and the paint looks like rubber or plastic, which is not possible with conventional methods.

(Material republished from the website: AUDImanual.ru)