What to Use to Repair a Pinhole in a Bathtub

De-Waxing Solvent

• Clean the pinhole and the top of the bathtub surrounding the hole with a de-waxing solvent. The de-waxing solvent removes any wax buildup or buildup of cleaning products from the tub. Apply the solvent with a microfiber cloth and rinse with fresh water. Once you completely clean the tub, pat the surface dry with a microfiber cloth. The microfiber cloth will not leave behind any pills or debris.

Sanding the Surface

• Sand the area around the hole with an orbital sander, using a 36-grit sanding disc. A damp cloth wiped across the surface removes any fiberglass dust left behind by sanding. Clean the surface with more of the de-waxing solvent, cleaning off any residue or dust clinging to the bathtub. When sanding the bathtub, wear a mask over your mouth and a pair of goggles. As you sand, you release fine particles of fiberglass into the surrounding area. Inhaling those particles or getting one caught in your eye is potentially dangerous and painful.

Resins

• Apply a dab of marine resin or another type of waterproof resin to the pinhole. Marine resin is a waterproof material used in the repair of fiberglass boats and other marine equipment. Smooth down the edges of the resin onto the surrounding tub and let dry for several hours. Place a piece of fine-grit sandpaper on top of the marine resin. Gently sand the area, using a circular motion. Wipe a damp cloth over the top. Sand the area until the resin feels smooth and matches the surrounding area.

Finishing the Repair

• Colored epoxy hides the repaired area, making it blend with the surrounding tub. Paint colored epoxy onto the surface of the tub, covering the repaired area. Hold the brush at an angle and smooth out the edges, feathering the epoxy into the surrounding tub. You can skip this step if you have a white tub or the resin matches the color of your bathtub.