Hi Shawn,
thanks for the tips. I think I will stick with 1/4 for the bottom only and do my stringer on the side panels. I will glass the whole cockpit area on the inside, deck also in front and behind the cockpit. As to flotation, I thought that if I put in extra thin bulkheads I would make the foam compartment completely waterthight and won'd have the problem of it not trying out completely. I will just fillet in the bulkheak - the front one will go right were the forward deck beam is, so there should be no problem with getting a tight seal on the deck side also, in the stern I will propably install and additianl deck beam and do the same thing

Any thoughts?

: You might also consider using the mildly expensive BS 6566 Okoume instead of
: the super-pricey BS 1088. It's still more than Lauan, but much, much
: better quality.

: Not that Lauan is strictly taboo--I built my Chesapeake 17 for $250 with 4mm
: 1088 bottom and side panels, 1/8" Lauan doorskin deck, and Raka glass
: and epoxy. It works just fine! (It would be even better if I'd been more
: careful with my epoxy--it's overweight at 57 lbs.)

: That will help a lot!!

: I'd lean toward 1/4" on the bottom and sides, and only 1/8" on the
: deck.
: I used 1/8" on the deck and still cracked my deck in front of the
: cockpit by applying too much pressure from underneath while rolling.

: Also reinforce your deck (on the inside) behind the cockpit where you apply
: pressure while entering and exiting the boat.

: You probably don't need the 1/8"--the foam should work well by itself.
: Pete Rudie put expanding foam in the bow and stern of his Guillemot 17.

: Happy building!

: Shawn