Fixing minor chips and scratches in your coachwork isn’t rocket science, it’s an art form that any handyperson can do. Preparation is the key to success and success means fixing that chipped or scratched coachwork so it looks like it had never been scratched or chipped. Success is refinishing the scratch or chip so the patch looks like the original finish.
Preparation is the first key to success. The first thing that you need to do is to find a place where you can control both the temperature and airborne dust. The ideal temperature is 75 degrees Fahrenheit. If the temperature is 70 degrees Fahrenheit or less, the paint won’t dry quickly enough and if the temperature’s over 80 degrees Fahrenheit the paint will dry too quickly to form a proper bond with the metal. Dust is your archenemy, so if need be, construct a temporary spray booth/tent out of a cheap plastic drop cloth available at a home center. WARNING: If you work under a tent, wear a respirator so you do not inhale the fumes that can damage your respiratory system and make you ill.
The second key to success is using the right primer, clear coat, and paint. The parts department at a dealer selling and servicing your make and model vehicle should be able to supply you with these items. If they don’t have them in stock, they can special order them for you. Another option is to go to an auto body paint dealer. A word of caution here, only use primer, clear coat, and paint made for auto bodies, do not use Rustoleum or some other general purpose metal finish because they will not bond properly with the sheet metal.
The third key to success is to follow these steps in preparing and painting the chipped area.
First, mask off the area around the dent or scratch using masking tape. Apply the tape so it encloses an area that includes at least ¼” of undamaged finish. Using an artist brush or some other similar applicator, use alcohol or lacquer thinner, cleanse the enclosed area of all dirt and road grime. If the chip or scratch extends down to bare metal, use a piece of 40 Grit emery cloth to remove any rust and to scratch up the bare metal. The metal needs to be roughed up for the primer and paint to adhere properly.
Second, using an artist brush or similar applicator, brush on a thin layer of primer. Your goal here is to get as thin a coat as possible, just enough to cover the bare metal without any lumps or high spots. Your goal here is to try to keep the primer on the bare metal and not get any on the surrounding finish. Once you have applied the primer, seal up your tent against dust and let the primer dry for 24 hours.
Third, using an artist brush or similar applicator, apply a thin layer of the touch up paint. The idea here is to not try to fill in the full depth of the chipped area but to just cover the metal with a thin layer just as you did with the primer but make sure that you get the paint in all the corners. If you get too much paint on the surface and lumps form, you can use a cotton swab with a little lacquer thinner to remove the access. If the touch up paint is too thick as it comes from the tube, inject one or two drops of lacquer thinner at a time, shaking well each time, until you reach the right consistency. Once you are satisfied with your work, seal up your tent and let dry for another 24 hours. The paint will shrink considerably over the 24-hour dying period. If lumps form, use an 800-grit wet/dry sandpaper to smooth the out. Sand just the new paint. Be very careful to not scratch the good finish.
Fourth, repeat step three until the new finish is almost level with the old good finish. You want to stop just before you are level with the old good finish because you want to leave a slight indentation for the clear coat.
Fifth, wait about a week and apply the clear coat in layers just as you did the paint. If all has gone well, you may not have to overlap the clear coat on the good old finish. If not all has gone as planned you will have to overlap the clear coat to blend the new finish in with the old.
