How to Repair a Hole in a Damaged Bathtub

Prep the Area

Before you begin, make sure that your mask, goggles, and gloves are on because you’ll be working with substances that can cause slight irritation. Open windows to increase ventilation as you’re working.

Wipe down holes using alcohol and a soft cloth to remove any soap residue or grime. Sponges and a mild detergent will help remove dirt too.

Be on the lookout for smaller fiberglass fragments sticking out from the holes. When fiberglass gets damaged, these fragments tend to appear, hindering repairs. Use your utility knife to strip away loose fiberglass pieces around the holes to make them easier to fill. 

“When prepping the hole, be sure to cut out all the fibers and anything higher than the tub surface,” says Bob Tschudi, Expert Review Board member and Raleigh, NC-based general contractor. “For the best repair, you don’t want to feel the slightest bump when the project is complete.”

Patch the Holes

Now it’s time to patch the holes. If you’re using a bathtub repair kit, it’ll come with resin and a hardening liquid that you’ll mix to create the compound. You can also buy a two-part epoxy kit, which will come with directions on how to make the filler substance.

Create a workstation by mixing the ingredients on disposable cardboard with the applicator. Put down painter’s tape to create visible guidelines for the repair areas. However, you’ll need to remove it after applying the epoxy, so it doesn’t stick to the tub. 

Use a tool like a small popsicle stick or spatula to smooth the epoxy into the holes and push it down further, filling the entire gap. It’ll be easier to use smaller amounts of the compound because excess can be difficult to remove. 

“We like to use a flexible putty knife to smooth the epoxy, which you can find in all automotive supply stores,” says Tschudi. “I’ve seen some contractors use a credit card or retail-rewards card with great results.”

Keep timing in mind—once the compound is mixed, it dries pretty quickly. So you’ll need to work at a reasonable speed to make sure that doesn’t happen, or you might have to mix more filler.

Let the Patch Dry

Don’t be too hasty; although the compound hardens quickly, the repair area still needs time to dry. The timing will depend on the size of the hole or the epoxy manufacturer’s guidelines, but it could be a few hours to an entire day. 

As hard as it may be, it would be best not to shower during this time because you’ll mess up the repair job.

Sanding the Area

Once the patch is dry, it’s time to break out the sandpaper. Again, put down painter’s tape to give yourself some guidelines because sandpaper can create visible scratches on your tub. The lower the grit, the more coarse the sandpaper. Start with coarse, then finish with fine.

Using 80 grit wet or dry sandpaper, thoroughly rub the patched area to smooth out the filling, removing bumps or ridges. As you’re sanding and the compound gets smoother, use 400 to 600 grit wet or dry sandpaper to finish it off. You’ll know you’re done when you can’t tell the difference between the repaired area and the rest of your tub.

Apply Polishing Compound or Paint

You’re finally at the finish line—but there’s one more step left: Applying the finish. Since most tubs are white, your repair kit may come with paint similar to your tub’s color. Follow the listed instructions, and apply the paint with a paintbrush or roller. Or, if you don’t have a repair kit, buy a small can of white paint.

If painting isn’t your forte, some repair kits also come with polishing compounds. Apply it to the repaired area and buff with a soft cloth until it matches your tub’s sheen. Let it dry for another 24 hours before showering.