Repair of Minor Body Panel Damage

PROCEDURE

1. If there is no access to the back side of the body panel for tapping out the dent, pull it out using a slide hammer. At the deepest point of the dent, or along its edge, drill or punch small holes spaced at least 2.5 cm apart...

2. ...then screw the slide hammer stem into the hole and operate it. Tap lightly with a regular hammer at the edge of the dent to help the metal return to its original shape. After completing this procedure, the dent surface should be close to its original contour and protrude approximately 0.3 cm above the surrounding metal.

3. Using coarse sandpaper, remove the paint down to bare metal. This can be done by hand, but the tool shown in the photo will help speed up the process. Using finer sandpaper, approximately No. 320, feather the paint over an area of at least 2.5 cm (1 in) around the dent.

4. After removing the paint, check the surface by touch rather than by sight to see whether the metal is smooth enough. Tap down any high spots with a hammer and/or pull out low areas where necessary. Clean the repair area with a wax and silicone remover.

5. Following the instructions on the package, mix the plastic filler with the hardener. The mixing ratio is critical. If it is incorrect, the filler will set too slowly or too quickly, and you will not have time to apply and shape it.

6. Work quickly so the filler does not set. Using a plastic spreader, apply firm pressure to press the filler onto the metal surface, making sure it fully bonds with the metal. Shape the filler so that it approximates the original contour of the area and stands slightly proud of the surrounding surface.

7. Allow the filler to harden until it can only be dented with a fingernail. Use a file or the tool shown in the photo to rough-shape the filler.

8. Using coarse sandpaper wrapped around a sanding block or board, sand the filler until it is smooth and even. Gradually move to finer grades of paper, always using a block or board, and finish with No. 360 or 400 grit.

9. When the sanded area is finished, you should not be able to feel the transition from filler to bare metal, or from bare metal to the old paint, with your hand. Once this is achieved, remove the dust and mask off adjacent panels and trim.

10. Apply several coats of primer to the area. Do not spray too heavily, or the primer will run. Allow each coat to dry before applying the next. A professional spray gun is normally used here, but primer in an inexpensive aerosol can is available from auto parts stores.

11. Primer will reveal any defects or scratches. Fill them with glazing compound. Following the instructions on the package, sand the compound smooth with fine (No. 360 or 400) sandpaper. Repeat the glazing and sanding, applying glazing compound and sanding it, until the primed surface is completely smooth.

12. Finish sanding with very fine paper (No. 400 or 600) to remove excess primer. Wash the repair area with water and allow it to dry. Use a tack cloth to remove all dust, then apply a coat of topcoat paint. Do not attempt to rub out or apply wax to the area until the paint has fully cured (at least two weeks).

Repairing Minor Scratches

PROCEDURE

1. If the scratch is superficial and does not penetrate the metal of the panel, repair is extremely simple. To remove loose paint particles and wax coating, lightly rub the scratched area with a fine rubbing compound. Rinse the treated surface with clean water.

2. Using a small brush, fill the scratch with the paint used for the body panels around it. Continue applying paint layer by layer until the paint inside the scratch reaches the level of the surrounding panel surface. Allow the new paint to cure for at least two weeks, then sand the repaired area flush with the rest of the panel using a very fine polishing compound. Finally, apply wax to the treated surface.

3. If the scratch has gone through the paint, reached the panel metal and caused corrosion, a different repair procedure must be used. Using a penknife, scrape powdery rust out of the scratch, then coat the surface with an inhibitor primer to prevent future corrosion. Using a rubber or nylon applicator, cover the treated damaged area with glaze-type body filler. If necessary, especially when filling narrow scratches, thin the filler with solvent to form a very fine paste. Before the glaze-type filler hardens inside the scratch, wrap the tip of your finger in smooth cotton cloth. Then, dampening the finger with solvent, quickly draw it along the filled scratch. This leaves the surface slightly concave. Once the filler has hardened, the treated scratch can be painted.

Dent Repair

PROCEDURE

1. When repairing dents, the primary task is to pull the deformed surface out to bring it back to the original level. Do not attempt to restore the surface to 100% of its original shape, as this is not possible because the internal structure of the panel metal is disturbed by the impact. The optimum level for a dent is approximately 3 mm (0.12 in) below the surface of the surrounding undamaged body panel. If the dent is very shallow, pulling it out is not necessary at all.

2. If the concave area can be reached from the back of the panel, try to straighten the dent from the inside by tapping with a hammer with a soft face. While tapping, hold a wooden dolly firmly against the outside of the dent to absorb the impact and avoid overstretching the deformed panel metal.

3. If the dent is in a double-layer section of the panel, or if access to the back is not possible for any other reason, use a different pulling method. Drill several small holes in the concave area of the panel, placing them in the deepest parts of the dent. Then thread long self-tapping screws into the holes, leaving the heads protruding far enough to grip with pliers. Begin pulling the dent out with the pliers by the screws.

4. At the next stage, the dent must be removed from the damaged surface and from an area approximately 3 cm wide around it. This work is best done using a wire wheel or sanding disc installed in the chuck of an electric drill; however, hand sanding with sandpaper is equally effective. The final step of preparation for filling is to scratch the bare metal of the dent with a screwdriver or a piece of file, or to drill small holes in it to ensure maximum adhesion of the filler to the metal surface. Then proceed with the filling and painting procedures (refer to the materials presented below).

Repairing Rusted Holes and Perforations

PROCEDURE

1. Using a sanding disc or wire wheel clamped in the chuck of an electric drill, remove all paint from the damaged area and from an area approximately 3 cm wide around it. If an electric drill is not available, this work can be done just as effectively by hand with sandpaper.

2. After removing the paint, assess the extent of corrosion damage to the metal and determine whether it makes sense to proceed with the repair or whether it would be more practical to replace the panel entirely (if this is possible at all). New panels can be purchased far less expensively than many car owners think. It is often much faster and even more economical to install a new panel than to repair extensive body damage.

3. Remove all body trim from the damaged panel, except for those parts that can serve as a reference for reproducing the original shape of the deformed areas (such as the headlight bezel, etc.). Using metal snips or a hacksaw blade, cut away all loose, weakly attached, and irreparably corroded pieces of metal, then bend the edges of the hole inward with a hammer to form a recess for holding the filler material.

4. Use a wire brush to remove powdery rust from the damaged metal. If access to the reverse side of the damaged area is available, treat it with a corrosion inhibitor.

5. Before filling, the hole must be covered. This can be done by riveting or screwing a piece of sheet metal to the back of the damaged area, or by covering the hole with wire mesh.

6. After the hole is blocked off, the damaged area can be filled and painted.

Filling and Painting

PROCEDURE

1. Many types of body filler are available; however, for this type of work, the body filler paste supplied with body panel repair kits, with the hardener included in a tube, is best suited. To achieve a smooth and accurate contour of the filled surface, the paste must be applied with a flexible plastic or nylon spreader. Strictly follow the manufacturer's instructions (failure to do so may cause the filler to cure improperly). Mix a small amount of filler on a clean wooden or cardboard surface (handle the hardener carefully).

2. Using the spreader, apply filler to the properly prepared damaged area of the body panel (refer to the materials presented above). To achieve the desired surface contour and filler level, each stroke of the spreader must pass across the entire repair surface. As soon as the contour of the filled surface is close to the original, stop applying filler immediately, since it will begin to stick to the spreader as it hardens, forming lumps and leaving scratches on the surface. Continue applying layers of paste at intervals of about 20 minutes until the filled surface stands slightly proud of the surrounding panel metal.

3. After the filler has hardened, excess material can be removed with a file. Next begins the stage of sanding and grinding the filled surface. The best choice for this purpose is imported waterproof sandpaper (because it has uniform grit distribution and good abrasive adhesion to the backing). Start with coarse No. 180 paper and, progressively reducing grit, finish at No.

600. To achieve proper flatness of the surface being worked, wrap the paper around a block of firm rubber (wood or foam) or adhere it to the block. During sanding, the paper must be wetted regularly and frequently with water. This technique allows absolute smoothness and evenness of the surface to be achieved at the final stage.

4. At this stage, the sanded damaged surface should be surrounded by a ring of clean bare metal, ending in a gradually tapering edge of sound paint. Rinse the sanded surface with clean water, washing away all abrasive residue formed during sanding.

5. Spray a thin coat of light primer onto the sanded surface from an aerosol can. This will reveal any defects made during sanding, which can be corrected by covering them with a layer of fresh filler. Repeat the sanding and grinding stage. Repeat the alternating filling, sanding, and priming of the surface until a satisfactory result is obtained. When finished, rinse the surface with water and dry it.

6. The surface is now ready for painting. Spray painting of the vehicle should be carried out in still, dry, warm, and dust-free air. Conditions in a large, enclosed, heated room best meet these requirements. If circumstances require painting the body outdoors, pay close attention to selecting suitable weather conditions. When working indoors, suppress dust by spraying water on the floor. If only a single body panel is being painted, cover the adjacent undamaged panels. This precaution minimizes the visible difference between the old and new paint colors. Trim elements such as chrome decorative strips, door handles, etc., should also be covered (or, preferably, removed). To protect surfaces that are not to be painted, use adhesive tape and old newspapers, applied in several layers.

7. Before using the aerosol, shake the can thoroughly, then spray a test surface to practice your painting technique. Apply a heavy coat of primer to the prepared surface. Build up the thickness by applying several thin coats. Using plenty of water, sand the primed surface with No. 600 water-resistant sandpaper until it is perfectly smooth. Allow the primer to dry completely before final painting.

8. Apply a layer of topcoat, again building up the thickness by applying several coats. Start painting from the center of the repair area, moving the can in circular motions and widening the radius in a spiral until the entire damaged area is covered, plus a ring of sound surrounding paint about 5 cm wide. 10 – 15 minutes after applying the last coat (preferably no later, so as not to damage the edge of the fresh paint as it begins to set), remove the newspapers and adhesive tape covering the adjacent body panels. The paint fully cures in approximately two weeks. After that, to smooth the transition to the fresh paint, treat the repaired surface with very fine polishing compound. Finally, apply a layer of wax to the panel.