Could I have DRY foam in my 1985 mach 1?

I have removed some of the flooring in my 1985 mach 1 bowrider, there is foam on both sides of the stringers none in the middle. In the middle I have a 24 gallon aluminum gas tank and ski locker storage. The foam appears to be very dry at the top. I removed a piece down about 1 inch and it still is bone dry. I think the bottom could also be dry but am worried removing some to test would open up the cells so water would start entering. I have heard of closed cell foam but have never seen it. I would imagine it was not available in 1985 but I don't know. The stringers are glassed in and seem very solid. It looks like 2x material and is even doubled up at some points. I would like to leave the foam if possible and replace the rear half of the deck?

Re: Could I have DRY foam in my 1985 mach 1?

I would like to leave the foam if possible and replace the rear half of the deck?

Click to expand...

Ayuh,... Anything is Possible,....
If you don't find evidence contrary, Go for it...

Re: Could I have DRY foam in my 1985 mach 1?

The foam could be dry. My boat is set up the same way. Even though the stringers are rotten, so far the foam on the outside of them has been totally dry. The only foam I had that was wet was below the ski locker, which never dried out.

You can test it by cutting out cores. Just get a piece of thin-wall pvc and cut teeth into one end. You can twist it down into the foam and pull out a core sample. If it is dry just put it back and seal up the top before replacing the floor.

Re: Could I have DRY foam in my 1985 mach 1?

i agree with bondo but you have to know for sure....

boats with wet foam, look good on the top of the foam.

you need to take a core sample....

take a one inch pvc pipe and cut two "teeth" in it....then insert the pipe into the foam.....all the way down. if the foam is wet at all........out it comes....all of it....
do this in several places.....like about 20 places.....10 each side.

dont worry about opening the cells on the foam......just replace the sample...or if you are really worried you can get some foam in a spray can and shoot it in the core holes

the foam is actually the easy part.....dont worry about it......
but be sure......if you put a new floor over wet foam....all your work is in vain..for lots of reasons.....but weight being one of the worst.

cheers
oops

Re: Could I have DRY foam in my 1985 mach 1?

I've been asking myself the same question on my project boat ('95 Crestliner Sportfish). I'd like to think that by '95 they'd figured out how to make foam that would stay dry. From what I can see the foam looks to be in good condition. But, I'm not certain either. I guess I'll be taking some core samples too.

Re: Could I have DRY foam in my 1985 mach 1?

I just removed the foam from my boat. There's really no way to tell unless you core it or remove it completely. All the water had collected on the underside of the foam. I probably had an extra 80 to 100 pounds of weight in my hull, good riddance!

Re: Could I have DRY foam in my 1985 mach 1?

the problem i found with sprayed in foam was it impeded water flowing to the bigle to get pump out. mine was salt water which seem to have some electrolisis (sic) and corrision. the only way i would use 2 part/spray foam would be to box out the ribs so the foam could never actualy touch the hull or ribs this should allow any water to flow freely to the rear

joe