how to fix a small crack in a fiberglass spa/hotub?
Answers:
You can buy fiberglass repair kits from home improvement centers or a place that sells boats. If you are going to try and match a color, I would suggest you hire someone that does fiberglass repair for the best results, well worth the money!
Other answers:
Duct Tape
Duct Tape
Completely dry and clean out the damaged area and fill with fiberglass resin and sand smooth.Epoxy works well too.
Fiberglass resin but it will not stick unless you sand it first and I recommend sanding some deep grooves into to allow the resin something to grip. If you do not it will fall out.
Usually newer spas and tub are fiberglass on the outside but a sheet of acrylic molded for the inside fiberglass does not stick very well i recomend glassing from back side to good grinded glass. Then lightly dremel out crack a little and fill with 3m5200 let dry for at least 72 hours.