Painting the plastic components of a dirt bike can change the look of the bike or restore a like-new look to weather worn or damaged parts. Like painting metal, plastic requires preparation to provide an adequate surface to which the paint can bond. Without the proper preparation and materials, the paint will peel from the part in a short time. Using paint marked for plastic use and creating a clean, contaminant free surface will ensure the paint lasts for the life of the plastic part.
Mix two tablespoons of degreasing detergent and 1/2 gallon of water in a one-gallon plastic bucket. Place a clean rag in the cleaning solution.
Clean the plastic with the detergent solution soaked rag. When the plastic is grease and oil free, rinse it with clean water.
Attach a 180-grit sanding disc to the DA sander. Sand the surface of the plastic with the DA sander to remove corrosion and sun damage from the plastic's surface.
Scrub the sanded surface with rubbing compound and a scouring pad. Remove the dried rubbing compound from the plastic with a clean dry rag.
Clean the surface of the plastic with an aerosol plastic cleaner and a clean rag.
Mix the plastic adhesion primer per the manufacturer's application instructions. Pour the mixed primer into the cup of a paint gun.
Hook the hose form the paint gun to an air compressor. Spray one heavy coat of plastic adhesion primer to the plastic. Allow the primer to cure for 20 to 30 minutes. Apply a second coat of primer to the plastic. Allow the primer to cure for 12 to 24 hours.
Sand the cured primer with 400-grit sandpaper until smooth.
Wipe the sanded surface with a clean rag or tack cloth to remove the sanding dust from the plastic.
Spray flexible paint onto the prepared surface with a spray gun until evenly coated. Allow the paint to cure for 24 hours before installing the painted part on the dirt bike.