Polycarbonate is a thermoplastic polymer that is durable yet easily moulded and thermoformed. These traits allow the plastic to be used in a variety of products, including eyeglasses and electronics. Polycarbonate sheets also are used in construction, and may be referred to by trademarked names such as Lexan, Makrolon or Makroclear. You can add a painted finish to a polycarbonate sheet if you properly prepare it. If you do not properly condition polycarbonate for adhesion, finish failure will prove unavoidable.
Wash the polycarbonate sheet with a water-based soap, using a nylon sponge. Thoroughly rinse all residue from the polycarbonate using wet rags, or the base primer will not adhere to it. Let the sheet dry for two hours.
Roughen the polycarbonate sheet to enhance its adhesive qualities. Sand the polycarbonate with 100-grit sandpaper and a power sander until it feels rough to your fingers. Take your time and be thorough, or the bonding primer will eventually flake off.
Protect surfaces next to the polycarbonate sheet with masking tape. Cover the floor beneath the polycarbonate with dust sheets.
Apply acrylic bonding spray primer to the polycarbonate sheet. Maintain a 20 cm (8 inch) space between the polycarbonate and spray tip to prevent sagging. Let the sheet dry for at least two hours.
Apply acrylic spray enamel to the polycarbonate sheet. Maintain a 20 cm (8 inch) space between the polycarbonate and spray tip to prevent sagging. Let the sheet dry for at least two hours.
Never try to paint directly over bare polycarbonate sheets, or peeling will ensue. Likewise, never try to prime over unsanded polycarbonate, or flaking will result. Latex paint won't hold up on a polycarbonate sheet. Do not undervalue the cleaning process, or the polycarbonate sheet may shed the bonding primer.