closed cell compared to marine plywood

[kodiak]

I am not new to boat building but I am building my first boat for myself. Just wanted to know two things. First how much more difficult is it to use newer composites (closed cell, kevlar, etc.) compared to plywood in composite small boat construction. Weight is my main factor not strength and cost. And two where can I find more in depth info on products and there production in my 18 ft. flats boat for super shallow water in Florida?
Thanks

[kodiak]

how does it compare to closed cell core material like klegacell and core-cell
Thanks

[sailr]

No reference to it at Noah's. Where do you get the stuff? I've searched using google and found nothing. HELP!

[sailr]

I'm in Land O' Lakes, just north of Tampa. I found polygard on the net but there's no reference to sheet materials.

Thanks!

[Noah's]

The main advantages of closed cell foam such as Corecell and Klegecell over plywood is a significant savings in weight over plywood and reinforced urethane such as Penske Board. A secondary advantage is it is impervious to rot, so very low maintenance. Typical foam density for boats up to 50’ is 5 lb. per cubic ft, Balsa is about 10, plywood 30 to 40, Urethane 10 to 40. Cost of foam core, polyester resin, “E” glass construction is comparable to Marine Plywood/Epoxy. Epoxy with foam core is more expensive, but you are usually able to trade this off with a lighter laminate so there is some saving in material and weight. One disadvantage of foam core is lower compression strength than Balsa or plywood so it is necessary to use high density foam or plywood inserts where you are bolting hardware.
Plywood is easy to use, cost effective and light enough for smaller boats, under 20’, as well as interiors and transoms, but foam core should defiantly be considered for larger boats, particularly where low weight is desirable.