I'm making 2 seats for my brother-in-law out of Spruce. They are turning out very light and look amazing. Used 3/4" spruce and cut it to 1 1/2" strips. Will be caning them in the next day or two. Question is will that wood be strong enough? I'm trying to keep the weight down as it is a Bell kevlar canoe but don't want them to break.
"Canoeing through a postcard"
-Brother in Law Mark
It's probably a good Idea to check them for strength before you do all the caning work. You could space a pair of rails to the canoes width and add weight to see how they hold up but they will have more than dead weight force on them when someone plops down on them. I think in the end you'll have to actually space the rails and sit and bounce on them to get the real world feel for how they will hold up. Laminated seats have been around for a long time using strips of ash and basswood to lighten them up. My idea for lightening my seat is to use 6, 1/8" strips of western red cedar laminated together with epoxy. It works in my head but I haven't done the testing yet. Post some pics on your seats .
90% of the wood seats out there whether factory made or by hand are made of black or white ash. Black being lighter and more springy. The other 10% are of other hard woods like cherry, mahogany, or other woods. While I want to say that spruce will work well, I would be a bit concerned especially since they are 3/4" thick. You didn't mention the species of spruce that you are using. Sitka spruce is a but more resilient than say, white spruce. But all spruce is a softwood, and while flexible, might lack the strength you need. I'm just not sure.
As suggested, place the finished frames on something that simulates their placement in a canoe and sit your butt on them and see how they feel. It takes 8 hours to hand-cane a seat and you don't want to find out after they are done.
Help keep the flying moose flying by supporting BWCA.com