fixed the leaks, now its time to fill the foam back in, the foam has been ordered but does anyone know what the hard resin type coating is on the very bottom, it seems to be like fiberglass resin that really seals the regular foam. its on a Tiger river spa.........thanks

It is a pour foam material, something like this:
http://www.fiberglasssupply.com/Product ... _foam.html

don't bother trying replace the hard stuff. No point really. By the way...it's 60 lb. density foam.

thanks for the input!

It depends, if you live in an area prone to carpenter ants, they'll infest the open cell stuff well before they try and get through the 60lb density foam that Dan linked to.

The stuff Dan linked is the same stuff Hot Springs supplies it repair centers with. We use it here in SW florida, as we get alot of rain. Open cell foam will soak up alot of the moisture from the rain, then insects are attracted to the moisture, particularly carpenter ants. While insects sometime infest virtually anything, you greatly increase chances of keeping wet, open cell foam around.

Absolutely...I refoamed one and then stored it outside for a month because the people wanted to do some work on their deck. When I went to put the final 60lb coat on over the replaced foam it was mostly gone from ants.