Auto primer paint is a necessary step when you’re repainting a vehicle. It prepares and protects the metal and ensures the paint adheres properly. There are several types of auto primer paint, so it’s useful to know which to use and when to use them.
You need to be right down to the bare metal, or to level filler, when you apply primer. Auto primer paint is usually sprayed on. The number of coats of primer you’ll use will depend on the type of primer. With a urethane primer, for example, you’ll use no more than 4 coats with 3 of them wet on top of a base coverage that’s been allowed to cure.
When using primer on a filler area, you need to extend the primer area some 4 to 6 inches beyond the area of filler to avoid possible problems with eventual paint coverage of the filler area. You also need to ensure the filler has cured properly. You might need to use a heat lamp to encourage the process. Don’t be in a hurry. It’s vital that the filler has ample time to cure, or your final painting won’t look anywhere near as good as it should.
Epoxy auto primer is one of the best primers that helps to prevent corrosion. It works on both metal and fiberglass, giving excellent adhesion, which is what you need for painting. It seals well, sands well and offers ideal adhesion for paint.
You need to be certain all the rust has been removed from the metal and that you’re applying epoxy primer to bare metal. The advantage is that epoxy primer usually doesn’t need to be sanded after it’s been applied to the metal so it’s a quick auto primer paint. You generally need no more than 2 coats of epoxy primer.
The number of coats you need for urethane primer makes the auto primer paint process longer, but it gives a stronger bond and often a better gloss on the final paints coats. You shouldn’t use spray paint primer with a tip that’s too wide. Generally 1.4 millimeters is adequate, although some manufacturers will recommend wider tips. Use a gravity feed spray gun for the best coverage.
Primer needs to be allowed to cure properly after each coat if you’re applying more than a single covering. You need good coverage of the entire area and the primer has to be absolutely dry before you move on to apply paint. Spray evenly and not too thickly. Where the primer requires the addition of a hardener, make sure you have the proportions correct before you spray.
If you’re sanding between coats, use a very fine grit and wash with a damp cloth to remove all the dust before you apply the next coat. When you’re applying auto primer, always wear a respirator mask and safety goggles. You don’t want to be breathing the fumes. Goggles, rather than safety glasses, will help to keep spray out of your eyes.