Tilt-A-Tub: Like a ride at an amusement park, hot tubs line for a spin on this machine. While rotomolding produces an affordable product, the manufacturing equipment comes with a hefty price tag: about $1 million.
Credit: Dream Maker Spas Tilt-A-Tub: Like a ride at an amusement park, hot tubs line for a spin on this machine. While rotomolding produces an affordable product, the manufacturing equipment comes with a hefty price tag: about $1 million.
Credit: Cal Spas

Awareness of rotomolded spas has grown in recent years for consumers as well as industry members. The durable, no-nonsense alternative to acrylic spas serve as an attractive entry product for buyers of more modest means.

Rotomolding has been used commercially for decades to make a wide range of products including kayaks, storage tanks, waterproof flashlights ... and the list goes on. It works by loading a predetermined amount of plastic powder into a heated aluminum mold, which is then rotated in multiple axes simultaneously (see sidebar). As the mold spins, the plastic powder inside melts and adheres uniformly to the mold walls.

The result is an economical and predictable process, which until relatively recently has been overlooked by spa manufacturers. Not any more. Rotomolded units now account for a “significant share” of the spa market, according to Dave Wright, vice president of Dream Maker Spas in Lake Mary, Fla. “We’ve seen phenomenal growth since acquiring the company in 2011. … Our new product designs, accomplished in large part by this technology, have been huge for us.”

As Wright explains, one of the big drivers behind this growth is convenience. “Consumers demand the best value, but they also want products that are easy to use. Because of rotomolding, you can pick up a spa on your way home from work next Friday, stick it on your patio, fill it with water, and plug it in. By Saturday morning you’ll have 103-degree water with a nice whirlpool action, with very low operating costs and minimal maintenance.” In contrast, the majority of acrylic spas run on a much higher voltage and often requires a visit by a licensed electrician.

Clearly, rotomolded spas are here to stay.

A tale of two plastics

Convenience is great, but would be rototubbers must be sacrificing something, right? Maybe, or maybe not. From a material perspective, traditional acrylic spas share many of the same qualities as their lower cost polyethylene cousins. Both offer durability and impact resistance, and can be formed into most any shape imaginable. Rototubs also can be equipped with mood lighting, waterfalls and sound systems, just like acrylic spas.

Because acrylic is smoother and shinier than polyethylene, many consumers shy away from the utilitarian appearance of a rototub. That could be an expensive mistake. Since the rotomolding process enables more efficient production of spas than the acrylic equivalent, the industry can offer entry-level rototubs at substantially lower prices. Casey Loyd, president of Cal Spas in Pomona, Calif., explains that a conventional spa requires far more manual labor to build than a rotomolded one — assembling the frame, applying multiple layers of backing material and fiberglass insulation, and installation of the acrylic shell and components into the housing. All of that takes time. “On a rototub, you pop it out of the mold, drill a few holes, and mount the equipment pack. That’s it. Where a conventional spa costs a dollar to build, a rotomolded one might cost 60 cents.”

Having your cake, and eating it too

That’s not to say manufacturers make a killing on these things, only that they don’t have to skimp on quality to meet low cost points. Rototubs are typically equipped with the same filters, heaters, and electronics seen in more expensive acrylic models. And since most rototubs are “plug and play,” the owner can drain the thing and bring it to his buddy’s next Superbowl party without any installation help.

But this portability comes at a price: Count the number of jets in a rototub, and you may come up short. The unit’s 110 volt power generally means a single pump which limits jet count. “Thirty jets is the highest you can go on a rotomold spa right now and still remain plug-and-play,” Loyd explains. “Any more than that and performance suffers.”

Still, said Loyd, a 20-jet rotomold spa with a two-speed pump is a pretty good deal. “Sure, I can get around in that new Volkswagen, but do I like my Bentley better? Absolutely. Rotomolded spas serve a real purpose in the marketplace.”

Getting in on the game

Because of rotomolding’s many advantages, spa makers are beginning to capitalize on the technology, but it’s not for the faint of heart. Total investment may run upwards of $1 million, with a big chunk of that going towards tooling the machine up. A mold for a rototub is going to cost five times that of an acrylic vacuum mold, according to Loyd. “It’s an expensive process to get setup, and you have to make quite a few units to pay back the capital expenditure,” she says. “At the end of the day, however, it’s definitely the best way to produce a spa with the lowest possible price point.”

No one would argue that saving money is a wonderful thing. Yet Sean Mahoney, North American business manager for Vista, Calif.-based Watkins Manufacturing Corp., says there are other dynamics at play when someone shops for a hot tub. Convenience and features are certainly important to consumers, but the spa industry should maintain a clear distinction between entry-level spas and premium spas. “People need a reason to trade up. It’s good for the dealers, and it’s also good for the consumer,” says Mahoney. “Consider a car dealership who only sells compact cars. They’re not going to be around long. The result is that the consumer has fewer places to go car shopping.”

Mahoney explains that it’s the same with spas. By offering entry-level, portable rototubs alongside high-end acrylic models that do everything but mow the lawn, a dealer can be successful as a one-stop shop. “Retailers want to have products that appeal to all segments of the marketplace, from first-time buyers to consumers with money to burn. And by building a full spectrum of products, we can offer consumers a variety of spa options while giving dealers the chance to up-sell. It’s a win-win for everyone.”

This last point was one of the drivers behind Watkins’ acquisition of American Hydrotherapy Systems in December 2012. By purchasing the Ontario-based company, Watkins was able to expand its product line to include rotomolded spas. President Steve Hammock sums it up this way: “Our dealers can now start more conversations and delight more clients with an excellent, low-cost product, and make a reasonable margin besides. But perhaps the best part is that our customers get great value for the money and a hot tub they are proud to own, enjoy and brag about to their friends.”