Many amateur do-it-yourselfers have difficulty getting paint to adhere to plastic surfaces. Because plastic is slick and nonporous, it is ill-suited for paint adhesion. No kind of paint will stick to plastic unless it is properly conditioned prior to application. Once the plastic is prepared, any paint will stick to it. However, certain paints are more suitable depending on the location and function of the plastic surface.
Paint will not adhere to plastic unless it is first abraded. Plastic surfaces should be sanded with a fine-grit sandpaper to provide a tooth for the new finish to adhere to. Never use sandpaper with a grit below 120, as this may mar the plastic with scratches.
Once the plastic is abraded, it requires a primer. Acrylic latex primers are appropriate if the plastic will be coated with water-based paints. An oil-based primer is suited for plastic only if it will be paired with an oil-based paint.
Plastics that bend require paints with elasticity. Latex and acrylic paints are appropriate for malleable plastic surfaces because they provide enough flexibility to move with the underlying surface. Oil-based paints cannot bend with malleable plastic and will eventually chip.
Firm plastic surfaces can be painted with acrylic, latex or oil-based paints. Oil-based paints provide glossy, durable, smoother-looking finishes. Appliance epoxy paint provides similar qualities for those who would like to avoid oil-based paints.
Ordinary latex paints are suitable for interior plastic surfaces. However, exterior plastic should be coated with acrylic latex paints. Acrylic latex paints provide extra elasticity. This helps them to expand and contract in varying temperatures.