: Hi Dick,

: I have not tried to laminate glass onto foam but I will give you my reasons
: for thinking fiberglass would delaminate from foam after sustaining a bump
: from rocks, etc. About a year ago we had a long decussion about this
: subject and there were several links offered up for looking into this and
: I check out all of them. One link was a surfboard builder that used a foam
: core that was tough but quite expensive. He laminated over the foam core
: with (graphite-Kevlar) sp. , can’t think of the name I want but you know
: what I mean. After extensive use of his surfboard the laminated surface
: had become so delamated that it flopped loosely from the foam. That’s when
: I decided to stop thinking about building a foam boat out of pink or blue
: foam which is much softer the foam he was using. When I got home from my
: kayak trip last year and got to looking at my scratches I saw some dings
: on my boat and realized that if it had been foam I would probably had a
: delamination there because the foam is so soft that the glass would easily
: pull away from it. Now if you put so much glass on your boat to stiffen it
: up then you defeat the purpose of having a light boat by using foam in the
: first place. When it warms up here in IN I will epoxy some glass on blue
: foam and test it. I would like to know for sure, myself.

: Take care,
: John

Aircraft are built using these techniques. Keep in mind they are not running into rocks, but the structure is very sound and light weight. I have taken a panel built with 3/8" foam core having 3 layers of 6oz cloth on both sides and beat it with a hammer. Why? because I could . Really though, a relative of mine built a seahawker amphibious biplane and he cut off the sponsons (wing floats) because the design had too much drag. He was throughing them out so I grabbed them and proceeded to see just how strong his airplane really was. I beat them with a hammer and there were only very small white marks (delamination) from where the hammer struck at an angle. Building a sandwich with glass and a foam core is very structurally sound.

One potential problem is if it gets too hot, the foam can be affected and actually start to melt. but that shouldn't be a problem in a kayak.

I was at a workshop on this type of construction and to ensure a good bond between the foam and the glass as well as to avoid excess epoxy (weight)in any pores of the foam, it is first seal coated.

The seal coat consistes of mixing microballoons with epoxy and using a sqeegee or body spreeder place a very very thin coat over the foam. Basically you are just getting the foam wet. Then place several layers of cloth over at 0, 90 and 45 degrees and wet out.

I'm still undecided if I will carve a minicell foam seat or try the "cheap" foam approach.

If I go the "cheap" foam approach, I'll post some pictures and results

Tom