Using 1/8" luaun

    Before you decide to build a canoe with 1/8" luaun plywood, I just want to make sure that you are aware of some it's limitations. One of the most serious is that it almost always has outside veneers that are very thin, with a thick inside core. This can cause weak scarf joints since most of the strength in any scarf joint is achieved by gluing the lengthwise grain in the outside veneers. Also, luaun plywood is often made using interior glue. This would be foolish in a boat that stayed in the water all the time, but with proper sealing and painting it may last a couple of years in a small boat like a QuickLap canoe.

    If you're still determined to use the cheap stuff, I've included a scarf-cutting file, (scarf125.sbp), that should work with the QuickLap cutting files; it's the same length as the 4mm scarf with thinner steps. You may have to fiddle with the size of the steps to compensate for thicker or thinner ply, so cut a scarf and see how it looks. If it's not quite right, modify the file as needed, flip the sheet of ply end-for-end, cut a new scarf, and use this sheet to cut the shorter pieces of the half13.sbp files. The one thing that won't cut right are the gains in the plank ends; they'll be shorter than they should be. With a little care and a sharp chisel, though, you shouldn't have much trouble extending them.

     Oh yeah, one more thing. Luaun plywood usually has one side that's much better looking than the other. My suggestion is to cut your scarfs so that the good side will be on the inside of the hull; it's a lot easier to sand and fill the outside of a hull than the inside. If that's what you decide to do, cut the scarf for sheet2.sbp with the good side up, and the scarf for sheet1.sbp with the good side down. That way when you're cutting your parts, the gains will both be on the bad side of the ply ( remember, you flip the half sheet panel over to cut out the parts!).

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