Epoxy and wood flour will work. May be the best there is. I use Titebond 3. It works great as a glue, not so well for me as a fairing compond.Yes, I'll "stick" with epoxy!
[quote It was the pictures in that thread you started, "A New Marsh Pirogue" that got me going on this.][/quote]
"A New Mash Pirogue" is seedtick and Keiths build. My son's boat viewtopic.php?f=10&t=8121 is similar. It has less flair and beam. If you are going to build it by "hand and sight", cut your sides to the length you want, wire them together and spread them to the look you want. Scaling the boats length and width will make it narrow and draft more.
Adding this will add weight and more drag to the boat .into, there'd be no real impact, nothing that would require a substantial rub rail. Maybe just a 1/4 in. piece of molding on the outside, something just enough to put a contrasting stripe of paint on, mostly for looks
3/8" wood be stiffer but much heavier and you may would need an extra sheet of 1/4" plywood, unless you used 3/8" for the whole boat.Maybe use 3/8 inch for the bottom? One the other hand, those bottom "ribs" do look more like battens and wouldn't really be in the way. . . I don't know.
You could add "bottom ribs" after you tried the boat, if they were needed.
If you can stand in the boat, the seat won't be too low. You will probably want it higher.In fact, I can see where it's possible I might just use one of those "throw-able boat cushions" for a seat. My UJ /8" would be hepirogue seat might be kind of high for seated paddling, won't know 'till I try it. One thing I can say about a fixed seat is that it would make the hull a bit stiffer
Food for thought:
24" to 26" wide floor, floor 12' long, Overall beam 36+", 11" to 12" high sides, 1/4" okoume, white oak or pine laddered gunnels, a detachable bench seat( removed for polling, attached to the sides for sitting), rocker = 3" bow and 2" stern