So to understand freeze/thaw breaks the closed cells of 2 part foam.
Is that correct?
Freeze meaning water is under the deck in the freeze months with no drainage and pools up and destroys the whole concept of poured foam.
Is that correct?
Closed cell foam is not viable in a freeze thaw scenario whereas the best method of protection is of course to keep your boat in a heated space.
Is that correct?
the foam is no different than an engine block. put water in a motor, subject it to freezing temperatures and the block cracks.
foam and water in an enclosed space, once it freezes, the water expands and some of the closed cell walls rupture and its no longer closed cell foam, so the space available for water to sit gets larger. over time, much of the foam is damaged and it becomes mostly open cell foam. this is known as a sponge.
eventually the amount of water in the cavity gets large enough that freezing actually ruptures what ever the foam/water was in.
the same thing happens to transoms and stringers on fiberglass boats.
in nearly all cases, neglect to pull the plug or neglect to seal a compartment or neglect to fix a hull breach are what leads to wet foam.
the key is to encapsulate the foam to prevent is exposure to foam, or to keep water out to begin with.
since nearly every boat I restored had wet foam, usually from either someone drilling a hole where it shouldnt be and not sealing it, or someone leaving the plug in and filling the whole boat up with water repeatedly. i dont blame the foam. I blame the lack of proper maintenance/operation
the 50's tinny fishing boat I have with foam under the seats is the original foam. pull the plug when your done fishing and water cant get to the foam. its been there for nearly 70 years and it will be there to float the boat should I ever have an incident where water does get high enough within the confines of the gunwales to need it to float the boat.
BTW........PFD's also break down when exposed to UV, water and freezing temperatures.