Toilets may suffer cracks on tanks and bowls due to age or wear. The cracks can spread across the toilet's porcelain, causing further damage and possible injury. Some toilet cracks may be repaired, while others may require you to replace the fixture. Repairing a toilet-bowl crack requires the proper tools and materials to ensure that the repair lasts.
Things You'll Need
High-speed rotary Dremel tool
1/8-inch diameter cone or ball-shaped diamond rotary grinder bit
White epoxy paste
Determine if the cracked toilet bowl can be repaired. If toilet bowl cracks are long and deep or comprise the integrity of the fixture, it may be more prudent to replace the bowl rather than repair it. Cracks that have a well-defined line and do not have numerous intersecting cracks may be repairable.
Clean the area around the crack with a clean cloth.
Drill a hole at the farthest visible end of the crack. Use the Dremel tool and the diamond rotary grinder bit. Drill the hole completely through the porcelain. This stops the crack from spreading. Apply drops of water to the area with a wet sponge to keep the Dremel bit cool.
Grind a "V" or "U" shaped valley along the entire length of the crack with the Dremel. Make the valley approximately 1/8-inch deep and 1/8-inch wide.
Mix white epoxy paste according to the manufacturer's instructions.
Apply the epoxy to the repair area using a popsicle stick. Add enough epoxy so the layer fills the repair area and is slightly above the surrounding grade. For vertical repairs, fill the area and apply a piece of clear packing tape over the repair.
Allow the epoxy to fully cure according to the manufacturer's instructions.
Sand the area with a coarse 60-grit sandpaper. Use finer grit sandpaper until the epoxy surface is smooth and flush with the surrounding porcelain. If you encounter any air bubbles, or the repair needs to be built back up, add more epoxy.
Wipe the repaired area with a clean cloth and acetone. Allow to dry.
Apply an even coat of refinishing spray and allow it to dry. Choose a refinishing spray that matches the color of your towel bowl. Apply an extra layer of clear spray within 10 minutes for a "gloss" look and to seal the surface.