> Has anyone had experience with using foam sealants for floatation?
> I'm talking about the expanding type you can get in a can from marine
> supply houses. It's a waterproof, closed cell foam. I was thinking
> of putting it in the bow cavity of my stitch-n-glue kayak (under construction)
> to give the hull added strength, rigidity, and for floatation?

> Thanks for any information available.

> Jim Ward

jim i have not used the sealant you are talking about but i have used GREAT STUFF, for many projects it is a canned foam you can get at Home Depot for a few dollars a can. It is a waterproof closed cell foam, it will degrade in sun light but that won't be a problem for your application. This foam expands ALOT!!!!! (do not believe the label when it says minimal expansion) Not only does it expand alot but as it expands it hardens and if it has nowhere to go, (if it is in an inclosed space) it will deform that structure ( i have seen the foam used to seal a house door that was working fine , the next day when the foam was cure it had twisted the door jam so much the door would not operate)

The best way for you to use the foam would be to install it before you install the deck that way the foam can expand up then you can cut off the excess when its cured.

The only other thing is that no matter what foam you use it is expensive so a trick you can use to reduce the amount of foam is to place a few empty capped 2 liter soda bottles in the bow and stern then use the great stuff to fill in the space around the bottles. this way you could add flotation to your kayak for the price of 1or2 cans of great stuff.

I plan on using this trick on my kayak a skin on frame.

don't worry about the bouyancy of the soda bottles they actualy have more bouyancy then the foam for equal volumes.