Painting cars is not for beginners with no knowledge of automotive paint techniques, but it can be done well if you have at least some experience doing paint and body work. The main techniques for achieving a smooth, even paint job includes properly preparing the surface, spraying the paint correctly and knowing a few tips about clearing up imperfections in the paint.
Every good paint job begins with getting the car's surface as smooth as possible. Begin by sanding the entire area to be painted with 120 grit sandpaper and a dual action sander. This step can be done by hand but goes much faster using a sander. Next, spray a coat of primer on the car and allow it to dry for an hour. Once the primer is dry, use a long sanding block with 120 grit sandpaper to sand the primer away. Lightly sand the primer so that it turns a lighter color. Keep the sanding block flat and level so that the primer is sanded evenly. This technique allows any low areas to remain dark and any high areas to show through the primer. Go back over the car and use a body hammer to gently tap high areas down. Go over low areas by grinding them down to reveal the bare metal. Fill this area with body filler and allow it to dry completely. Use the dual action sander and 120 grit sandpaper to smooth the dried filler. Spray primer on the repair and sand it again with the long sanding block.
Once the car is completely smooth, wipe it down with wax and grease remover and a microfiber towel. Spray one final coat of primer and allow it to dry. Lightly sand this layer of primer with 300 grit sandpaper, keeping the surface and sandpaper wet while sanding. Rinse the car and allow it to dry completely.
When spraying paint, make sure all of your painting materials are the same brand and line. Primer, paint, clear coat and reducer for the paint should be made by the same company. Mixing these materials with materials from another company can cause reactions on the surface of the car, even after the paint has dried.
Gravity-fed spray guns are by far the best type to use for spraying base and clear coat paints. Primer can be sprayed from any type of paint gun.
Spray the car by starting at the highest level. Begin on the roof and move to the hood, trunk and then sides of the car. This prevents an already painted area to become covered in overspray. Use short, even strokes and keep the gun about eight inches away from the car's surface. Overlap each paint stroke slightly. Allow each coat of paint 30 minutes to dry. Three to six layers of base paint should be applied, depending on your preference and how well the paint covers the surface.
Clear coat paint should be applied in the exact same way and pattern as the base coat. Three to eight layers of clear coat can be applied to the car, allowing 30 minutes of dry time between each coat.
After the paint has dried for at least 24 hours, inspect the car for runs in the paint. If there are runs or small pieces of dirt under the paint, use 800 grit sandpaper and water to sand them. Keep the sandpaper soaking wet while sanding to prevent build up under the paper. Once these areas have been sanded smooth, apply a mildly abrasive liquid buffing compound to a clean pad on an orbital buffer. Buff these areas or the entire car. The compound smooths all small scratches made by the sandpaper and brings out a deep shine in the clear coat.
