full foam shrinkage

[fatman]

No, I am not looking to start a 7 page thread on ff vs. tp so please folks, lets not go there.  Just one question to ask so let's keep it civilized. I spoke with a dealer today who happens to sell a well known brand of full foam and an equally well known brand of tp. He told me that full foam will shrink 1/2" in 5 years time regardless of the density used.  Is this true?

[Vinny]

It depends on if it's a male tub and how cold the water is.  

Sorry, I couldn't resist!

[Brewman]

  Did the dealer share with you the source of this information?  I'd be curious as to what entity made the claim, and what their interest in the issue is.
Brewman

[fatman]

 Did the dealer share with you the source of this information?  I'd be curious as to what entity made the claim, and what their interest in the issue is.
Brewman

The dealer said it was a conference through the MSPI. Wish I could give more detail but I took only brief notes.....

[Chas]

I have not heard that - and knowing some of the places where closed-cell polyurethane foam is used, I would say he got it wrong. Some random thoughts:

I have worked on many older tubs from various different brands, and I have seen no evidence of shrinkage in the foam. The spa flex tends to shrink over time, and that can cause problems if the designers don't allow for it in the layout of jets and other fittings.

I have dug out twenty-year-old tubs and the foam was gripping all the parts just like a new spa.

I know that foam shows up inside non-reinforced masonary walls as earthquake retrofit strengthening, and I think shrinkage would have made them look for another material by now.

And what about surfboards? I see them all over here in So Cal, and they seem to be fine after many years...

[ebirrane]

Could he have been talking about open-cell foam under the mistaken impression that alot of manufacturers use that type of foam in their tub?

-Ed

[Steve]

I knew someone would go there Vinny!

I have never heard of this shrinkage issue before and I doubt it has any validity to it.

Steve

[Spatech_tuo]

That's a new one on me.

[HotTubMan]

If anything, I could see some forms of foam expanding. Not the 2lb, but rather the 1/2# open cell foam. That said I have never encountered expanding or shrinking foam.

[East_TX_Spa]

I'm continually amazed at the things people fret about when looking at spas.

Terminator

[tootall]

Closed cell foam does not shrink other wise the bulding trade would not use it to seal cracks and holes with it.