The plastic on a four-wheeler consists of the fairings and fenders. Automotive paint should be used with the addition of a "flex agent" to give the paint flexible properties due to this type of application. Urethane paint is better than enamel for scratch and chip resistance and especially if it is a two-stage basecoat-clearcoat system. Two-stage paint results in a tougher and much more scratch-resistant surface.
Remove all the plastic parts to be painted. Repair all cracks using the heat gun and weld sticks. Heat the surrounding area of the repair and the weld stick as well and allow the weld stick to flow into the crack. Continue to heat the repair until smooth.
Clean the entire piece using a wax-grease-dirt surface cleaner; get into every spot to be painted. A good paint job depends on how well all the grease, dirt and dust is removed.
Look for any high spots or depressions. Sand them out as much as possible. Always wet the surface to be sanded and keep it wet until the sanding is accomplished. When all the sanding is finished, clean the surface again.
Suspend the parts with lengths of wire for painting. Clean the surfaces again this time, using the tack cloth, to remove all debris. Tape off any parts not to be painted using the masking tape.
Paint the parts with two coats of primer. Make the coats thin and hold the can 12 inches away from the part and always perpendicular. Paint one tack coat and wait for 15 minutes and hit it with the second coat.
Spray the part with the etching primer 15 minutes after the last coat of primer. Wet sand the part just enough to smooth out all the etching paint. Wash the part and dry it with a cloth and re-hang it.
Clean it again with the tack cloth to remove all the dust particles. Open and stir the base coat paint. Fill the first 30 percent of the paint gun supply cup with basecoat, filtering it through the paint strainer. Fill the supply cup with an equal amount of reducer. It is always a half-and-half mix or 50/50.
Pour 2 caps of activator to the mix. Set the air gun so there is no more than 50 PSI going into the gun and 18 PSI at the nozzle. These pressures can be set with the pressure regulators -- the one on the air compressor and the other on the gun. Keep the gun perpendicular to and about 9 to 12 inches from the surface. Keep it moving for an even pattern. Start to spray before the part and don't stop until you pass it so the paint does not pool.
Paint a tack or real thin coat followed by a cover coat in 15-minute intervals. Put two cover coats on the part. Look it over for any uneven spots and hit these again. Allow 30 minutes before applying the clearcoat.
Apply the clearcoat in the same manner, allowing 15 minutes between coats. Clearcoat should not be thinned. It just needs to have the activator mixed in or it will never dry. Paints are all different so read the instructions on the can for mixture ratio.
