How to Apply Fiberglass Gelcoat
- 1). Sand the surface using a palm sander and fine-grit sandpaper. The surface must be scuffed for the gelcoat to bond properly.
- 2). Clean the surface using acetone and a clean rag. Remove any grease or dust on the surface. Grease or oil can cause the gelcoat to bubble up and not cure properly.
- 3). Tape off the perimeter of the area being painted using painter's tape. Anything that must not be sprayed must be taped off or covered.
- 4). Add the gelcoat and hardener to the gelcoat gun as directed in the manual. The gun will mix the hardener and gelcoat while you are spraying.
- 5). Spray the first coat of gelcoat in a heavy mist. Spray as evenly and consistently as possible for the best results. Let the first coat begin to harden and get tacky. When it's tacky enough for the second coat, it will be a gel instead of a liquid. Spray the second and final coat so that it solidly covers the surface. Let cure until the gelcoat is hard and cool to the touch.
- 6). Wet-sand the gelcoat with super-fine wet sandpaper. Add marine wax and buff out using a clean rag. This will give the gelcoat a protective layer and a shiny finish.