Question for Chas about shells?

[Bonibelle]

Chas, so nice to see you back..you, more than anyone, can probably answer my question...and here it is:

How does the shell on a Caldera differ from the shell of a Hot Springs?
They are both manufactured by Watkins, however one has a fiberglass backing (I think) and the other uses ABS. Is that right? why two different methods? I am just wondering. :-/

[Chas]

It's good to be back! You of all people will appreciate this: I had back surgery on Tuesday the 4th, and I went back to work for the first day today! No pain! After three months flat on my back in pain beyond what I could handle, it couldn't have gone better. I am soooooo glad to be back! Thanks.

OK - now - you asked about shells -

Yes, the Caldera is made by thermo forming a sheet of acrylic and then applying many layers of fiberglass. They do it in Mexico, in a state-of-the-art facility. They do it in Mexico for two reasons: one, it costs less to do it there, and the other reason is that they can use the better - "hotter" - materials which tend to work better, but are limited by the EPA in Southern Cal. As a result, they have very few problems with this laminated structure de-laminating or blistering.

The HotSpring shell, on the other hand, is thermo formed of a special sheet of plastic which is comprised of acrylic and ABS plastic. That sheet is cast in large flat molds, rolled under a 'registration roller' to gauge the exact thickness, and then while it is still in a molten state, it has the second layer - the ABS - is cast on top. They might do it in the reverse order, it's not important. What is important is that the casting process bonds the two materials into one sheet which cannot come apart.

The shell is then checked several ways for flaws, and if it passes, it goes on to have a layer of high-density polyurethane foam  -30 pound- spayed on the back. That layer is around an inch thick, or just under. It is so important that this layer be perfect that it is applied by a robot spray arm which is computer controlled. It is also applied in a temperature and humidity controlled tunnel which people cannot go in. I don't remember just how hot or moist it is, but it takes the shells in on one end and they come out sprayed on the other end with steam rising off of them.

Now, since this shell is not laminated, it cannot de-laminate or blister. I have had one shell go bad in twenty years - and the factory suspected they had gotten a bad sheet, or it had been heated unevenly. In any event, a large blister raised in one end of the of the footwell area, it was the whole shell, not a de-lamination. The spa could have continued in service for decades, but HotSpring replaced the spa and paid me to deliver and install the new one.

 8-)

[Vanguard]

I had the opportunity to see the ABS/Acrylic process at Aristech some time ago.  It is a really neat process.  Really amazing to watch the two materials come together.

[hottubdan]

You are correct.

Hot Spring all ABS.

Caldera fiberglass backed.

Has been that way for 30 years.

The 2 brands are intentionally kept seperate.  Made in 2 different factories.  When Watkins bought Caldera the intention was to keep the brands seperate.

[Chas]

Yes, thanks Dan.

Did we mention that Tiger River is the same as HotSpring, and those two brands are built completely in the Vista, Ca plant - start to finish.


 8-)

[Bonibelle]

Thanks guys, my friend just bought a Caldera and was telling me about the fiberglass backing..and I thought I would ask you because that didn't seem right to me (being that both were Watkins products).

so glad you are feeling better, Chas! I had no idea you were having health issues.  

[Richs100]

My Italian heritage got the better of me with the subject line of this post.
I thought the answer would involve either clam or tomato sauce.
(that's what I like on my shells.....)

[Chas]

Alfredo  is good too...

 8-)

[Richs100]

Unfortunately, my love of the "Freddo" sauce was forever changed by:

(1) the lake scene in Godfather II, and

(2) the South Park parody of the lake scene with Cartman repeatedly striking Kyle over the head with a Whiffle bat (to no harmful effect) while saying that "Kyle will be dead in a matter of hours".

Since then, its been either clam or tomato when we "go to the mattresses".