I don't see any reason why it wouldn't work.
The wood does add a substantial amount of strength to the glass/wood/glass composite panel (in the longtitudinal direction only) which would have to be compensated for using foam. Nick's site has some data and graphs showing this.

Depending on what the intended use of the kayak is you are designing for in strength, you may not save that much weight (if it's for expedition style kayaking).

Rohacell foam would be very expensive too, unless you have a cheep source for it.

Doug K.

: I saw a "Laughing Loon Georgian Bay model" on the water recently
: and it is a very cool kayak for sure. I am familiar with the strip-built
: process(never built one though). Since I am a composites professional, I
: was wondering if anyone has any thoughts on exchanging the wooden strips
: for foam strips? There all all sorts of marine grade foams that may lend
: themselves to this technique. Using foam and graphite could yield a
: lightweight yak. I was concidering the use of Rohacell foam, or perhaps
: PVC and epoxy, or vinyl ester marine grade (hytex) resin. No particular
: design identified as of yet.Input welcomed!

: BTW-There are a few on-the-water shots of the Loon posted on site/pages
: linked below, which were taken during a recent kayak fishing derby in
: Redondo Beach, California at King Harbor-FYI . Thanks.