: thanks,
: Nick has provided a nesting layout along with his offsets. I've already
: re-nested the panels (on virtual paper) in several different ways in order
: to try to minimise the amount of sheets of ply that I might need. . . .

Looking at his nesting pattern at http://www.guillemot-kayaks.com/guillemot/information/kayak_building/stitch_and_glue_construction/free_stitch_and_glue_kayak_plans you can see that the whole design comes out to 17"2" long by 2'8" wide, and the design is only for one side. You need to double this. So even if you get the length from making up the difference with scrap pieces, you'll need 4 sheet of plywood, and have 4 pieces which are about 8' long and 16" wide.

: Based on what you guys are telling me, I'll probably do a
: 6"-8'-8'-6" partitioning. The ~6" sections can be cut out
: of the "scrap" areas of the main pieces, and I might get
: creative with what I scarf together for those areas while I'm at it. It
: doesn't look like the panels get too tortured in those spots.

: Anyway, I think I'll use 5.2mm ply for the hull bottom and sides, and 1/8inch
: ply for the deck and decksides (tumblehome panels) rather than to just use
: 4mm ply for the whole thing.

From a quick look at the layout and offsets, it appears you can get your bottom, sides, and deck sides from 2 sheets of plywood. fou are looking at Nick's diagram, basically, you'll cut the bottom parts from the area where he has drawn the deck. Rip your two sheets into 2x8 pieces, scarf them, then layout the lines. The bottom is about 188 inches long, and you'll have about panels which are about 190 inches, so that will fit fine. The sides and deck sides you'll need to cut and then add some pieces to the ends. So you might as well cut all three shapes form the same 5.2 mm ply.

Then you can use just one panel of 1/8th inch for the deck. Rip it into 4 pieces roughly a foot wide and butt joint those into two long panels. There will be plenty of "waste, in long, kinda triangular pieces which you can use for extending the tips, and for material for backing up the butt joints. Having a but joint in the middle of these panels may add some tresngth to the cockpit coaming area (it will be double thickness there) which is an area where you'll put all your weight when boarding.

Check a few of the writeups by previous builders of this design. I could be wrong, but as I recall there were a few who complained that 5.2 ply was a bit stiff and they had to work to get it to bend into shape. I don't know which pieces gave them the most problems.

: Besides the 5.2mm ply is a light color (pine,
: probably) and the 1/8th inch ply is dark luan. I realize that most
: recommend buying bs1088 marine ply, and that the difference in cost is
: minimal in the big picture, but this is my first build and uh, well...

I'd go for a light colored deck and a dark hull. That would be cooler on sunny days.

Also, while there are many boats built with 1/8th inch plywood, I wouldn't use that for a deck on my boat unless it had glass covering both inside and out. That is personal, and mainly because I'm a bit (and then some) larger and heavier than the average kayak paddler. If I was to slide along a deck made of 1/8th inch material during a re-entry, or if I had to drag someone elses boat over my deck to help it drain during a rescue, I'd worry that a thin deck just might crack under the weight.

One option I might consider would be making the bottom and deck from 5.2mm and making the sides and deck sides from 1/8th inch. Or, I might consider making the entire boat from 5.2mm. I might even think of making the hull, sides and deck sides from the 1/8th inch to keep things light, and making the deck from 5.2 mm to support the out-of-water loads.

As you can see, there are quite a few ways to go. With your paddling conditions none of these considerations might apply.

Hope this helps. Good luck with your project.

PGJ