How to Repaint Fiberglass

By Jay Kurz

Fiberglass paint or gel coat is a fiberglass resin that is pigmented to match any color. Gel coat also can have additives to protect against UV rays when used on boats or other applications that see a lot of sun. Over time, gel coat can lose its shine and become dull or begin to crack from wear and tear. These problems can easily be fixed by refinishing the gel coat. Gel coat and gel coat spray guns can be found at your local marine supply store.

Things You'll Need

  • Respirator
  • Palm sander
  • Fine grit sandpaper
  • Coarse grit sandpaper
  • Fiberglass filler
  • Hardener
  • Putty knife
  • Rags
  • Acetone
  • Gel coat
  • Gel coat gun
  • Gel coat hardener
  • Boat wax
  • Buffer

Step 1

Using your respirator, sand the entire area that is being refinished using a palm sander and a coarse sandpaper. Taper the walls of any deep cracks or fractures in the fiberglass. Scuff the old gel coat until there is no visible shine left on the surface.

Step 2

Fill any cracks or fractures with fiberglass filler. Fiberglass filler needs a hardener to cure, which will come with the filler. Thoroughly mix the filler and hardener as recommended on the container. Apply using a putty knife. Smooth out the filler, making sure it is level with the surrounding fiberglass. Let cure until it is hard and cool to the touch.

Step 3

Re-sand the entire surface, including the filler, with fine grit sand paper. Sand until the surface is smooth and ready for gel coat. Be sure there are no indents or uneven surfaces.

Step 4

Wipe the entire area, using a clean rag and acetone. Remove all dirt, dust and grease from the surface. Any grease or oil will cause the gel coat to bubble up and not bond correctly.

Step 5

Using painters tape, cover anything that you don't want to get gel coat on. If there are large areas that need to be covered, use plastic sheeting.

Step 6

Using the gel coat gun, spray the first coat of gel coat on in a heavy mist. The first coat should not completely cover the surface. Spray on as evenly as possible for the best results. Let cure until it is tacky. Apply the second coat so that it completely covers the surface. Let cure until the gel coat is hard and cool to the touch.

Step 7

Apply a coat of boat wax and buff out. This will give a shiny finish but also form a protective layer over the gel coat. Regularly apply wax to prolong the life of your gel coat.

References & Resources