Originally Posted by
mike carrigan
Using government specs, the foam cannot retain more than 1% of it's total weight of moisture.
Perhaps one hundred pounds of closed cell foam can retain less than one pound of water.
We maintain one tenth of a pound of retention.
Talking about foam is always a topic that has much disagreement and views that vary.
One popular view is if the foam is cut it will then admit water. Yes, that's true, but only the cut area. A tiny fraction.
We, as very many, boat builders ,use closed cell foam, a "PVC" foam so to speak. We've had a tremendous success with it for about sixteen years now with no cases of waterlogged foam.
When using the word "foam" it's all that not a bad idea to define the "foam" we're talking about.
This is not the sixties. Yes, I have lived thru waterlogged foam, but not for many-many years.
The plastics industry has come a very long way.
A closed cell foam stringer system, encapsulated with perhaps "3610" or "2415" or the like, has no natural enemies. It's very strong, creates an extremely good bottom, lighter, more efficient in most uses, will retain extremely low % of moisture.
In some cases wood might be better. It's all in the application and intended use.
If it were me gutting an old boat, replacing stringers, floors, transom, I'd probobly use wood. Less money, and if an XL wood is being used, no rot worries. I wouldn't go to the expense of plastics or foam. No way is it going to be cost efficient and the wood will be much easier to work with.
Consider, in your home, how much moisture has your PVC piping absorbed?