Plastic shower stalls are usually made of fiberglass resin or from polystyrene. Although plastic is durable and long-lasting, it is possible to crack the stall. If you decide to replace your shower stall, expect to spend a good amount of money doing so. However, as an alternative to replacing a shower stall, you can purchase a fiberglass patch kit and patch the crack. This is cost-effective and will take less time than removing and installing a new stall.
Add a cup of white distilled vinegar to a gallon of water and wipe the shower stall down with the solution. This will break down any oil buildup. Wipe the surface of the shower down with a clean, dry towel.
Create a V-groove over the crack by running the edge of a file across the crack. The V-groove should run approximately half the depth of the crack.
Blend the fiberglass filler with the catalyst and mix it in a container with the mixing stick supplied with the fiberglass kit.
Apply the fiberglass filler over the V-groove with the mixing stick. When completed, the fiberglass filler should rest above the surface of the plastic tub. Allow at least 24 hours drying time.
Sand the fiberglass filler flush with the surface of the shower with an orbital sander equipped with a 1,000-grit sandpaper. When completed, the fiberglass should rest level with the surface of the shower.