I've never used marine-grade plywood, and my only experience with lauan is in the boat I'm constructing now. I don't know how they compare in strength and rigidity, but I've had to glass both sides of all my lauan - it just seemed too flexible without it. I'm sure that this flexibility was more noticible on the design I'm building (SK S&G) with it's flat deck sections. I'm not sure that marine-grade plywood would have behaved much differently in those areas, but the plans only call for taping interior seams.

With all the extra glass, and the thicker (5mm) lauan, my boat is not going to be a lightweight. Once outfitted, I'll be happy if it comes in under 50lbs.

Also, the lauan I'm using is butt-ugly, but that's okay because I've always intended to paint it. If you want to finish bright, lauan might not be the best choice. My $0.02

Ross

: I paddled Dean Trexel's Outer Island recently (thanks Dean, beautiful kayak!)
: and am interested in getting some impressions from those of you who have
: paddled the Night Heron and Shearwater's Oyster Catcher, which appear to
: my untrained eye to all be rather similar. Also, for stitch and glue, how
: important is marine grade plywood as opposed to plain old lauan? It seems
: like many of you have used the cheap stuff with good results. Opinions?
: Thanks.