Standard Exterior Paints
All paints should be well dried and cured before installation of signage. Use two lighter coats rather than one heavier coat when painting signs that are to be decorated with films as drying and curing will be faster and more complete. Flat latex paints are harder to stick to than others.
Some latex surfaces may be incompatible with pressure sensitive graphics. A prime coat may be applied before vinyl installation. A good on-site test for dryness of a painted vehicle surface is to press a thumbnail into the paint. If the nail edge leaves an impression the paint is still to soft too apply graphics upon.
Gel Coats and Urethane Paints
Fiberglass that has been cast into a mold usually ends up having a waxy film on the surface due to the mold release agent used in the fiberglass lay-up operation. Without these wax or silicone mold release coatings, the gel coat would bond to the mold and easy removal would be impossible. Much of the mold release coating comes off the mold with the gel coat leaving the installer with a surface to which it is very difficult to adhere films. This coating must be removed before graphics are installed. Use the recommendation of the mold release company for remover fluid and use IPA as a final wipe.
All gel coats and urethane paint coatings require a cure time which will vary with temperature, humidity and level of catalyst or hardener. Wait as long as possible before installing graphics so that outgassing problems are reduced. A symptom of outgassing is the formation of tiny bubbles after the installation has been completed.