If the scratch does not go down to the bare metal, it is relatively simple to repair. Start by rubbing lightly on the scratched area with a fine rubbing compound. Make sure to remove any loose paint or build up of wax, and then rinse with water. Carefully apply some touch-up paint to the scratch using a small brush. Continue to apply thin layers of paint until the paint in the scratch is level with the paint outside of the scratch. Let the touch-up paint dry for a couple of weeks. Then, with some very fine rubbing compound, rub the spot out, blending the new paint with the old. Apply a coat of wax over the repaired area as a final touch.
If the scratch is deep enough to have exposed bare metal, a different technique is required to repair this. Start by removing all loose rust from the bottom of the scratch, a pocket knife works very well for this. Apply a rust preventative paint to the scratch and allow it to dry. Using either a rubber or nylon applicator apply a coat of glaze type filler to the scratched area. It may help to mix the filler with a small amount of thinner to fill in narrow scratches. Before the filler dries, take a piece of cotton cloth and wrap around the tip of your finger. Dip the cloth of thinner, and quickly wipe along the surface of the scratch to ensure that the surface of the filler is slightly hollow. After the filler dries, it can be painted over as we described earlier. Finish the job up with the rubbing compound and wax the same way as instructed above.
Dents or slightly more challenging to repair than scratches. The first step in repairing a dent is to pull the affected area out until it is as close as possible to its original shape. There is no reason to try and restore it to its original shape entirely because the metal in the damaged region has stretched on impact and cannot be restored to its original shape. It is best to try and bring the dent out to a point that is approximately 1/8 of an inch below the level of the metal surrounding it. In the event that the dent is very shallow, don’t bother trying to pull it out.
If you can get to the backside of the dent you can hammer it out from behind using a rubber hammer. Be certain to hold a block of wood on the outside of the dent to absorb the shock of the blows. This will prevent the metal from stretching. If the dent is in an area of the body where there are double layers of metal, or you cannot access it from behind, there is another approach. Drill several small holes in the damaged spot, making sure to get a couple holes down in the deepest parts. If you have a dent Puller, you can use it to pull the dent out. If you do not have a dent puller, don’t panic, there is always more than one way to get the job done. Screw some long self tapping screws into the holes far enough that they get a good grip. Using a good pair of locking pliers, such as Vise Grip, lock onto those screws and pull the dent out.
And after you have completed pulling the dent, it is time to get the paint off from the damaged area and about an inch or so around it. You can accomplish this with a wire brush or a sanding disc in the drill motor, although it can be done very easily by hand with sandpaper as well. Take a screwdriver and score the metal of the damaged surface to prepare it for filling. This will provide the filler with a good grip.
There are many types of body fillers available. They also sell a body repair kit that contains the paste and a tube of resin hardener which I highly recommend for this job. Mix the filler as recommended by the manufacturer, and apply it to the damaged area with the plastic applicator supplied in the repair kit. After the filler is completely hardened, remove the excess with a body file. By using progressively finer grades of sandpaper, starting with 180 grit, and finishing with around 800 grit wet or dry paper, a flat surface achieved. Wet or dry sandpaper should be rinsed in water periodically. This will help you achieve a very smooth finish that is desired in the final stage of this repair. The area that you have repaired should now be surrounded by a ring of bare metal, which should be surrounded by a finely feathered edge of good paint. Rinse the area with clean water to remove the dust created from sanding.
Spray a light coat of primer over the entire area, and allow it to dry. The primer will reveal any imperfections. Repair the imperfections with fresh filler or glazed filler and smooth the surface again with sandpaper. Continue to repeat the spraying and repairing until you are satisfied that the surface of the filler and the feathered edge of the paint are perfect. Rinse the area with water and allow it to dry.
Now you’re ready for paint. Painting must be done in a warm, dry, windless, and dust free environment. Coating the floor with water will help the dust settle. Be sure and pick the day carefully when you paint. If you’re just going to paint one panel, mask the rest of the car off to avoid overspray. Spending a little extra time here making sure you do a good job masking, will save you some major headaches later on.
Spray the area with a thick coat of primer, the thickness should be built up using several thin layers of primer instead of just one thick coat. Allow the primer to dry. Rub down the surface of the primer using 600 grit sandpaper until it is smooth. While you are working, rinse the area with clean water and allow the primer to dry before applying additional coats. Begin by spraying a top coat of paint and again building up the thickness by using several thin layers of paint. Start spraying in the center of the repair and use a circular motion working your way out until the whole repair area and about 2 inches or so of the surrounding original paint is covered. Remove all the masking tape and paper about 10 to 15 minutes after you finish painting. Do not allow your masking tape to adhere with the new paint or you will have a real mess when you pull it off.
Allow the paint at least two weeks to harden. Rub the repaired area out with a very fine rubbing compound to blend the new paint with the existing paint. Finish it off with a coat of wax.
