How to Repair Holes in Fiberglass Tubs

Lead Image
  • 3-24 hours
  • Intermediate
  • $60-150
What You'll Need
Safety glasses
Respirator mask
Mild detergent
Oxygen bleach
Stripping agent (acetone stripper)
Fiberglass epoxy resin mix
100, 200 and 400-grit sandpaper
Fiberglass cloth/fabric
Tongue depressor
Popsicle sticks

Fiberglass tubs develop oles after years of use. These holes can be patched up easily with epoxy and fiberglass fabric, and can be done by yourself. Follow the step-by-step guide on how to repair holes in your tub.

WARNING: Many of the substances you'll need to use for this task are either toxic to inhale or touch. Make sure the bathroom is well-ventilated and wear a respirator mask, gloves (and when sanding, safety glasses) to stay safe.

Step 1 - Prep the Area

Determine the extent of damage. Fiberglass cloth is often used in fiberglass repairs, but you cannot use it in all hole repairs. It is best to use in wider holes. For narrow yet deep holes, epoxy resin is enough to repair the damage.

Now is the best time to clean and disinfect the tub. Create a detergent solution. Use a sponge to clean the tub of grime and soap residue. Mix oxygen bleach with water in a 50:50 ratio and wipe it on the tub using a sponge. Wear a respirator mask and open windows before applying the beach. Then rinse the tub with water and allow the surface to dry.

Strip the hole area with a stripping agent. Sand the area around the hole and the hole itself with a 100-grit sandpaper. Allow to dry, then brush the area with a paintbrush to remove sanding residue.

Step 2 - Fill Holes

Mix the fiberglass epoxy resin using the proportions that the manufacturer recommends. Using its applicator or a popsicle stick, fill the holes with the resin. Use a thinner applicator to push the epoxy further to the bottom and to fill the hole with epoxy completely. Wipe the excess epoxy, especially the film that touches the surface of the tub. Allow the epoxy to cure according to the packaging instructions. Use 200-grit sandpaper to flatten the area and level the epoxy filler to the tub's surface.

Step 3 - Patch Wider Holes

Cut a fiberglass fabric according to the width of the hole. Apply the mixed epoxy resin on the hole halfway full, then insert the fiberglass fabric to patch the hole and reinforce the resin. Apply more epoxy on top of the fiberglass fabric until it becomes invisible. Wipe excess epoxy film on the surface. Allow the epoxy to cure.

Use 200-grit sandpaper to flush epoxy with the tub's surface. Cut protruding fabric around the edges of the hole and continue to sand. Apply another coat of epoxy on top, let it cure and sand it to even it out. Epoxy resin usually takes 24 hours to fully cure, make sure no one touches it during the curing process.

Step 4 - Finish and Buff

Most tubs are white in color, so you might not need to repaint the tub after filling the holes. The epoxy is opaque white in color and matches most white tubs. If your tub has a tint, you have to paint the repaired area.

Apply wax to the entire tub to help repel soap residue. Purchase wax that does not contain chemicals that can cause skin irritations.