Fiberglass tub surrounds can become dull or stained after years of use. To bring the surround back to life, replace it or repaint it. Replacing a tub surround can be expensive and labor-intensive. A tub surround can be repainted to look like new with a little work and a few supplies. Fiberglass is painted with gel coat, which is a fiberglass resin pigmented with color. All painting supplies can be found at your local marine supply store or home improvement store.
Clean the tub surround using a scrub brush and bathtub cleaning solution. Remove all soap scum buildup and dirt from the surface of the surround. Rinse the surround out with clean water.
Remove all the removable fixtures on the tub surround.
Sand the entire surface using fine-grit sandpaper and a palm sander. Sand the surface until it is smooth and completely scuffed.
Remove all the dust from the surface of the tub surround using a rag and acetone.
Mask the surrounding walls and any fixtures in the tub with painter's tape. Cover any toilets or cabinets around the tub using old sheets. This will protect from any overspray while you are painting.
Mix the gel coat and hardener as directed on the containers. Use a small bucket and a stir stick to mix the gel coat thoroughly.
Add the gel coat to the spray gun and begin spraying the tub surround. Spray the first coat in a heavy mist and let it begin to harden. When it begins to harden, add a second coat to the surface, solidly covering the tub surround. Let that coat begin to harden and apply a third light coat. Let the gel coat cure until it is hard and cool to the touch.