Plastic and fiberglass bathtubs may develop cracks around the drain due to improper or age support at the underside of the tub. Generally, if a steel or porcelain tub is cracked, then it will have to be replaced.
Repair Kits
You have two options for the system utilized to perform the repair. The first employs a body filler, similar that used on cars and boats, together with a gel coat that adds the shine into the finish. The other kind is a two-part epoxy system that self-mixes the stitch. Several product lines come in a range of tones to match standard tub colors, like white, light yellow and tan.
Preparation
It’s essential that the area around the drain is totally dry before you do the repair. This permits a secure bond of this filler and gel coat. If the tub spout drips when the water is shut off, then turn off the water supply into the house and open a garden faucet to drain the system down. With the tub dry, use the fine-grit seams that came with the kit to rough up the area adjacent to the crack. Remove any sanding debris with a moist cloth and dry the area with paper towels.
Body Filler
The directions that came with the repair kit will provide you the correct proportion of catalyst and filler. Use a plastic putty knife to mix the stitch on a sheet of glass or plastic before the color is consistent and instantly install it in the crack with the knife. Remove any excess with the knife, permit the filler to cure and then sand it smooth with 100-grit sandpaper. Remove any debris before applying the gel coat with the supplied applicator. Once the gel coat goes, you can buff it with 1,000-grit garnet paper for a consistent finish, if desired.
Two-Part Epoxy
This type of repair serves a dual purpose, in that it welds the edges of a crack in a vinyl or fiberglass tub. Part one and part two are self-mixed in the supplied applicator, so there’s no calculations needed. Just make certain to remove any excess prior to the epoxy hardens, or you’ll have a buildup that will have to be sanded. Once the filler is hard to the touch, then apply the gel coat with the supplied applicator. Again, buff the finish with the garnet paper, if desired.