Fibreglass, a plastic resin, is used in boats, outdoor pools, cars, and household objects like doors. This material can be challenging to paint, since it's slippery. Homeowners completing a renovation project have a choice between paints, depending on the use and location of their fibreglass item.
The Sunrise Window company recommends an acrylic latex paint for fibreglass. Acrylic paint adheres well to fibreglass, overcoming one of the main challenges to painting this material. Acrylic paint is less likely to crack and blister, and will hold up well to cleaning. This water-based paint is easy to apply, and contains fewer chemicals, so is more environmentally friendly. Use acrylic latex paint for indoor or outdoor fibreglass projects.
For fibreglass boats or other outdoor objects, use a urethane paint. Unlike acrylic paints, urethane is not water-based; it relies on a chemical solvent. Since this paint contains more chemicals, it can be harsher to apply; wear a protective face mask and work outside when using urethane-based paints. For projects that take a beating, urethane provides high performance and resists chipping, wear and tear, and other damage, while still providing a shiny finish. Urethane works best for outdoor projects.
AsktheBuilder.com recommends an acrylic and urethane resin blend for fibreglass projects. This paint provides both acrylic and water-based polyurethane (not the chemical solvent type of urethane). This paint has extreme adhesive properties and saves you time--you don't need to clean your fibreglass before applying the paint; the paint is so strong that it can bond to old paint even over a dirty surface. This paint saves time and labour.