> I am a high school wood shop teacher. Last year I had 7 students make
> wooden kayaks now I have many who want to try but the cost is too great
> for many of my students. (last year they averaged $285) Is luan an
> acceptable alternative for the okoume plywood we bought last year? Does
> anyone have any other cost saving ideas? thank you for any helpful advice.

I have been using 3mm luan to construct kayaks for years with no problems.

When working with laminated materials you should inspect the edges of the cutout pieces for voids and repair (inject thickened epoxy with a syringe) or reject them if need be. The 3mm luan seems to have a better quality core than does the 5mm.

I often butt-join the panels and use a 3 foot long piece of luan as backing to provide additional reinforcement in the cockpit area. I typically add layer of polyester "random weave cloth" (bought from the garden center - sold as a ground cloth for weed control) to the back (inside surface of the kayak) of the panels. Do this before assembling the kayak because it is easier to work on the panels when they are flat. The polyester cloth is stiff and does not drape. This does not use as much epoxy as glass would and you have to waterproof the inside anyway.

The outsides are glassed/finished as usual.

Spruce 2x4 can be ripped into shear clamps.

Enjoy your building.

Hank