Hot tub shells are the backbone of your hot tub. They are what give your portable spas their structure, hold all of the hot tubs water in, contain your hot tubs jets, and keep all of your hot tub parts neatly stowed away from getting wet. Without the hot tub shell, you wouldn’t have a hot tub at all.
The most important asset when it comes to hot tub shells is strength and durability. If your hot tub shell cracks, water is going to leak everywhere depending on the severity of the crack. If you don’t get to the crack in your hot tub shells quickly, they will just get worse, until your spa tubs are basically unusable.
The next thing you want to look for in a hot tub shell is the way it looks. This is in the eye of the beholder, but some hot tub shells definitely look better than others – and you know this when you see it.
You should clean your hot tub shell every time you refill your hot tub spa, which you should do every 4 months or less. Use hot tub chemicals to clean the hot tub shells, and some sort of sealer to protect your hot tub shell from minor scratches. You should then apply a stain and scale remover to protect the hot tub shell from discolorations due to bacteria and other parasites.
Fixing your hot tub shells can be done, but mostly with smaller cracks. With bigger cracks can be attempted to be fixed but many times it doesn’t work out. Epoxy resin and plumbers putty will work good with fiberglass hot tub shells.
Mix up your plumbers putty and spread it onto your hot tub shell with a putty knife, making sure it is getting into all of the cracks. Remove any extra putty and let it cure for 1-1.5 hours.
Then you want to mix up a two part epoxy resin (the first part being the resin and the second being the catalyst to make the resin harden/cure). Smooth it over the bad area of your hot tub shell. Let this cure for at least 1 full day.
Sand the resin so you don’t cut yourself on your hot tubs shell. The last step is adding a thin coat of the silicone that you use for bathtubs. This will give your hot tub shell that finishing touch and keep your hot tub shells going strong for a couple more years.