How to Refinish Car Paintby Chris Moore
There are a number of reasons why a car's paint job might need refinishing. The paint can be peeling, or the car could be rusted or have some other type of body damage. If you want to refinish the paint so it looks like new, you can't just apply a new coat over the old one. This is a complex process involving sanding over the surface and making sure it is completely smooth, and shouldn't be taken on by someone inexperienced in car painting.
Clean the entire surface with soap and water, then use a wax/grease remover. Make sure you remove all wax, grease and other forms of contamination from the old finish.
Cover all surfaces and panels of the car that are not being refinished, using tarp, masking tape or other materials that will completely mask those areas.
Remove all rust from the surface. You might be able to remove small traces of rust using WD-40 type oil or sandblasting. If there is larger, more significant rust, you may need to cut that metal away and then weld patches of 22- to 18-gauge metal using a wire-feed welding torch.
Repair any dents in the panel. "Pull" or pound the dent back out using either a hammer from the inside or a suction cup with a handle on the outside. If there are large dents and you want a perfect surface, you're better off having the whole panel replaced.
Sand down all the paint that remains on that panel. Rub the surface with 320-grit sandpaper until the old paint is smooth with no rough areas. If the paint's top coat is peeling, remove all the paint from the panel; a power sander might be needed for this.
Prime the surface, whether it is bare metal or still has layers. Apply urethane primer to the entire surface, then block the primer by wrapping 400-grit sandpaper around a ridged block and running it against the surface to smooth out the primer and remove any gloss.
Double-check to make sure the surface is completely clean and dry, that all surfaces not being refinished are masked and covered, then apply the top coat of paint, preferably with a good paint gun, using even strokes. If you are painting bare metal, apply two coats 15 minutes apart.
Apply three clear coats after the new top coat is dry, waiting 15 minutes between coats for the previous coat to dry.