How to Fix or Repair a Plastic Bathtub

A crack in a plastic bathtub can cause extensive water damage to the floor below the tub and the ceiling of the room below the floor.

A cracked bathtub can cause extensive water damage.A cracked bathtub can cause extensive water damage.
Damage can run into the thousands of dollars for repairs. If the damage is extensive, you'll have to rip out the tub to replace the flooring and, in many cases, you must rip out the ceiling below so you can replace it. If you notice a crack in your plastic bathtub, repair it as quickly as possible.

Wipe the surface of the tub dry with a towel. If the tub has a lot of soap scum, wipe it off with a bathtub cleaner and dry it. It is important to start with a clean, dry surface.

Cut a V-groove down the length of the crack with a rotary tool equipped with a triangle-tipped grinder. Extend the V-groove past each end of the crack by a quarter inch.

Wipe off the plastic dust with a clean towel.

Fill the V-groove with fiberglass filler. Pour the filler high enough that it rests above the surface of the plastic. Wait 24 hours for the filler to harden, unless the packaging specifies a longer curing period.

Sand the fiberglass filler flat with the surface of the bathtub, using the orbital sander equipped with 2000-grit sandpaper.

Things You Will Need

  • Clean towel
  • Bathtub cleaner
  • Rotary tool
  • Triangle-shaped cutter
  • Fiberglass filler
  • Orbital sander
  • 2000-grit sandpaper