If you want that professional finish that mimics the life-size automobiles, airbrushing is by far the best way to paint your model cars. Model car enthusiasts swear by airbrushing, and despite some of the specialty equipment involved, airbrushing is in many ways, easier than painting model cars by hand. The tools are easy and inexpensive to acquire at your local hobby shop, and you can begin painting almost immediately.
Select a good airbrush kit. Most come with all the necessary tools you will need, such as nozzles, hose, and jars. Entry-level kits will often use compressed air in a can to power the airbrush, however, you should look for a kit that includes a compressor, so you do not risk running out of air halfway through a paint job.
Prepare your painting area by laying out cardboard to cover your painting surface. For adequate ventilation, you may want to paint outside. One thing you can do to get a better finish is to take an old cardboard box, and punch a wire hanger through it, a few inches from the top. You can now hang your model pieces before you remove them from the mold to paint from all sides.
Assemble your airbrush. Follow your manufacturer’s instructions, however this often involves attaching the nozzle to the paint jar, and then connecting the hoses to the compressor. If this is the first time using your airbrush, be sure to test it first.
Prime your model. If your model needs to be primed before painting, you can apply the primer with your airbrush. For best results, make sure your model pieces are free of dust, oil, or other debris. Spray the model with a light coat of either white or light gray primer. Let the primer dry before apply your first coat of paint.
Paint the model. Once the primer has dried, usually within 24 hours, it is time to paint the model. Paint will often need to be mixed with a solvent before being used in an airbrush, or you can purchase paints specially prepared for airbrushing. The instruction manual of your airbrush will give you the specific consistency you will need.
When working with the airbrush, try to keep the nozzle level to avoid clogging, and to avoid spraying any areas of the model you did not intend to paint. Use even and steady strokes when working with the airbrush.
If you are happy with your finish, you can begin assembling your model. However, if you need to give your model a second coat of paint, or made any mistakes while painting, you can lightly sand out the paint blemishes with a little wet sandpaper mixed with water. Brush away any dust, and touch up your paint job.
Remove any over-spray. Model adhesives often have trouble sticking to painted finishes. Use rubbing alcohol to remove the paint from any part that needs to be glued.
Use light, even coats when airbrushing your model car, taking your time, and not stopping between passes.
Use the right paint thinner when mixing your paints. For example, if you are using an acrylic-based paint, use an acrylic-based thinner.
To get a better glide when using wet sandpaper, mix a little dish soap with the water.
If you are getting an inconsistent flow from your airbrush, it is usually because the paint is too thick. Thin the paint with the appropriate solvent.