In the present absence of time to write a full article here, I will at least temporarily post some useful links where some information can be obtained.
Here's a good, overall article to get one started:
www.amateurboatbuilding.com/articles/
howto/foam_sandwich/index.html
Automotive applications may provide some tips too: www.rqriley.com/frp-foam.htm
And here's a potential supplier to get an idea of prices: www.boatbuildercentral.com/
I would be amiss to not include what 'Sir Ian' once had to say on the subject, but his website is being rebuilt since his sad passing, so I will post these additional references instead.....
Video of Foam Core construction by Cerny Yacht Design
Reading matter on Foam Core construction by Boatbuilder Central
Information on Foam-Core Materials by JamesTown Distributors
The W22 also uses Strip Planking for the lower part of its Main Hull, as well as for the Amas. Either foam or cedar. See HERE for its Main Hull shoe."New articles, comments and references will be added periodically as new questions are answered and other info comes in relative to this subject, so you're invited to revisit and participate." —webmaster
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