Things You'll Need
Spray adhesion promoter
Normally, plastic must be abraded through sanding to encourage paint adhesion, or the paint will not bond. Unfortunately, this can make the surface look rough and unattractive. An adhesion promoter is the answer for anyone who wants to paint over plastic without roughing it up first. However, if you use too much, you can make the plastic look gummy. Apply only a small amount of adhesion promoter and use only short intermittent bursts or you may ruin the appearance of the plastic.
Dish soap can interfere with adhesion. Ensure that you have rinsed away all of the soap or you may have problems getting the adhesive promoter to bond.
Adhesion promoters are a type of clear primer ideal for preparing surfaces like fiberglass, aluminum, vinyl, glass, galvanized metal, chrome and plastic for better paint adhesion. They generally come in a spray can and are fairly easy to apply as long as you avoid the potential pitfalls that many amateur painters fall into.
Clean the surface of the plastic using ordinary dish soap. Rinse the plastic thoroughly. Allow the surface to dry before applying the adhesion promoter.
Spray the adhesion promoter on the plastic. Spray in short intermittent bursts rather than in one steady stream.
Allow the surface to dry for three hours before applying any paint.
Ryan Lawrence is a freelance writer based in Boulder, Colorado. He has been writing professionally since 1999. He has 10 years of experience as a professional painting contractor. Lawrence writes for High Class Blogs and Yodle. He has a bachelor's degree in journalism and public relations with a minor in history from the University of Oklahoma.