Glen-L.com

I notice that unlike a lot of the stitch and glue designs, where the notes typically state that either marine or exterior plywood can be used, the Rob Roy canoe calls for marine only, and there's also a note to say that 1/4" ply is too stiff, so it should use 4 or 5mm.

The closest plywood to that that's readily available to me is exterior grade 5.5mm (1/4" is 6.35mm, so this stuff is relatively close to the 5mm called for on this design)

Is it completely out of the question to try to build the Rob Roy with 5mm exterior grade ply? I understand the differences between marine and exterior grades, and I realize that it may be weaker and not last as long, but I am fine with that if I can make a boat that is safe, works properly and lasts for 2 years.

Thoughts?

I'm just guessing here,but given your criteria,I would say that you'd be OK.

That being said,I'd hand pick the sheets to make sure I had the best as far as interior voids,and the finish of the good side,so that you don't end up with weak/non fair areas.

That thickness may be a little stiffer to bend,but I'm not sure on that,and it may be a little heavier.

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