How Is a Hot Tub Made?

Ever find yourself wondering, “how is a hot tub made?”

If not, have you ever found yourself watching episode after episode of the formerly streamed-on-Netflix Discovery program called “How It’s Made?”

Lucky for you, I've been in BOTH of those situations. Check out this short five minute clip on the interesting process. Seriously: this show finds a way to make the process of paint drying interesting. And is addicting at an alarming level.

If you'd rather read about it, here's a quick summary of the whole process.

First, a piece of rigid acrylic is rested over a hot tub mold and then clamped and transferred to an oven that has heating elements both above and below the piece of acrylic. Once the acrylic is heated to the point that it begins to sag in the middle, it’s placed over the top of the hot tub mold.

There is a vacuum system underneath the structure that is then activated so that it takes the shape of the mold. Technicians working with the acrylic smooth it over any difficult edges that may not have taken proper form. Fans cool the shaped acrylic and it firms up in just a few minutes.

Operators then stack the hardened hot tub shell before the next process.

At this point, the tub is flipped over and resin is sprayed on the outside of the shell. Then, a rope of fiberglass twine is fed into a spray gun that chops the twine and mixes with the resin to give the shell a fiberglass coating that reinforces the acrylic. Technicians press out any air pockets in the fiber glass to ensure it’s as strong as possible.

Another spray gun is used on the underside of the tub that contains insulating foam. The lip of the tub is then trimmed with a circular saw so that it will sit properly in the hot tub frame when it is constructed later.

The edges are sanded and holes are drilled for the insertion of the jets—fun fact: modern hot tubs can have up to 100 jets. How many jets do you think Benny had? I mean, Elton John never really specifies.*

Working from inside the tub, an assembler tucks plastic jets into the holes while a worker on the other side pulls the jets through, applies sealant, and drives a nut into the assembly to secure it.

The tubing is dipped into sealant and connected to the jets. Narrower tubing pipes supply the air for the jets while wider tubes provide water. The tubing is connected to an intake pipe to a pump which forces air into it.

At this point, the hot tub is wired for mood lighting and all the wiring and plumbing is tested to make sure they’re in full working order.

More insulating foam is sprayed under the tub to enclose the pipes and hoses—this was my favorite part. The foam expands like a marshmallow in the microwave.

Foil backed plastic is wrapped around the tub to help keep heat within the spa. After that, the exterior paneling is mounted to give it that complete and polished look.

The whole process takes about 20 person hours to complete but it only took you about five minutes to read this/watch the video!

*Bad joke. I’m (sort of) sorry.