How to Fix Fiberglass Bathtubs
- 1). Clean the tub using a strong detergent, and a scrub brush. Remove any soap scum or buildup that is on the surface of the tub. Rinse the tub out and let it dry.
- 2). Put on a respirator, and sand the damage smooth, using 60 grit sandpaper on a palm sander. Scuff the damage and an extra 6 inches all the way around the damage. Remove all the shine of the gel coat until it is completely dull.
- 3). Clean the surface of the damage using a rag and acetone. Let the acetone dry.
- 4). Mix the fiberglass filler with the catalyst, following the recommendations on the containers. Use a small bucket and a stir stick to thoroughly mix the thick filler. Work fast after the filler is catalyzed because it will harden in 15 to 20 minutes.
- 5). Apply the filler to the damage with a putty knife. Completely fill the damage with the filler until its level with the surrounding fiberglass. Smooth the filler out with the putty knife, and let the filler harden.
- 6). Put on the respirator, and sand the filler smooth using 200 grit sandpaper. Sand the filler until it blends in with the existing fiberglass. There should be no visible seams left when you're finished.
- 7). Clean the surface with a rag and acetone, and tape off the perimeter of the repair using painters tape.
- 8). Mix the gel coat with the catalyst in a small bucket, following the directions on the containers.
- 9). Apply the first coat of gel coat to the repair using a felt roller. Let the first coat harden, and apply the second and final coat. Let the gel coat harden for 24 hours before running the water.