Hot Tubs and Acrylic Repair. My Spa is Blistering

Lately we have gotten a lot of few requests from customers regarding acrylic repairs on their spas.

Most of these request come from spa owners with older spas (10 years +). At that age the likely hood for acrylic repair or acrylic blistering increases exponentially.

Some of the reason for spa blistering;

The most common reason for spa blistering is that the spa has been left without water but with the spa cover on.  This can generate a tremendous amount of heat that can cause the thin acrylic layer to rise up like a blister.

How spa shells are built

Remember that the acrylic layer is only the top surface. The thickness of that layer varies between different parts of the spa. In some parts of the spa, the thickness is only 1/32 of an inch or even less.

Underneath the acrylic layer is typically a thicker layer of fiberglass. This is what gives strength and rigidity to the spa.  Between these layer is the adhesive that bonds them together.  One of the secrets to a high quality spa is this adhesive.  Each spa manufacturer has their own semi-secret formula for this adhesive.  A bad adhesive will allow for a separation between acrylic and fiberglass. This will more easily results in a blister forming and a crack in the acrylic layer

To repair the acrylic layer is often time consuming (=costly for the customer). We often hear; “How can it be so expensive to repair that little blister?". The reason for that is that most often the repair of a blister requires multiple visits by the technician. In addition, each technician capable of doing acrylic repair has undergone extensive, costly trainings.

Some customers opt to perform the repair themselves. If you are not concerned with the look of the repair. Like if the blister is at the bottom of a deep seat or in the filter areas, you can typically us a 2 component epoxy. Remove the blister first with a knife (don't puncture the fiberglass layer), then apply the epoxy generously over the blister area. Let it dry. Sandpaper smooth. That's it.

Remember that just because you have a blister or that the blister is cracked; it does not necessarily mean that your spa is leaking. Most of the time the crack is simply in the top acrylic layer and not in the structural fiberglass layer beneath.

Good luck in your blister repair.