We have an old fiberglass bathtub on the second floor that has three cracks about 8 inches long.
Water leaks through to the room below.
Experienced bath fixture refinishing specialists can often repair fiberglass tubs, but your problems sound like they may be too severe to be repaired and guaranteed, he says. It is my opinion that replacement would be your best option due to the severity of the cracks and the possibility of water damage to other building materials around and under the tub, including drywall, flooring and wood. Consult a bathtub refinisher. He doesn't recommend a spray carpet cleaner. Unfortunately, most topical sprays will not get down deep enough, and will also leave soap behind that will attract dirt just about as fast as the Coke.