: If you plan on "glassing" a stitch and glue kayak, what are the
: acceptable kinds of plywood to use? Cost is a consideration

Take can opener, grab can, open . . . ahhh, look at all the worms. Do a search in the archieves under luan, or lauan, for us purists, and you will find many opinions pro and con on plywood marine and otherwise. I've seen lauan doorskins for as low as $5 a sheet and you can go $40, plus shipping, for certified okouma.

My two cents worth is go with so-called 1/4" lauan (actually more like 5.2 mm). Perhaps you can even get your local Home Depot to donate it, or at least give you a break on the price. The ply is functioning as a core material to enhance the performance of the glass skins. Just about anything that has good adhesive qualities with epoxy will work as a core. My expensive sailboat uses blocks of end grain balsa wood and the builder brags about it. Even paper honeycomb is used in some marine applications.

Your kayaks will not be as light as some, but hell, these kids are young, strong and need the exercise. What's important is to give them the experience of this great activity. If they find it as addictive as most of the folks here they'll build another, and another will be lighter and better. There's nothing like seeing a complex three dimensional object come together from your own hands to open your eyes to the possibilities of what you can do with tools and time. There's something very magic that a boat provides that a bookshelf doesn't.

I've got a "Six-Hour Canoe" sitting behind the shop that I built it with a group at scout camp five years ago. It's never seen the water (liability issues at the camp), but served to fire an interest in boatbuilding in several boys. When I run into these, now, young men, they always mention the experience. So I urge and encourage you to follow through on your project.

BTW total materials used on the canoe were under $50.