Tim, I have no doubt that you'll be able to dry bend your spruce inwales successfully, providing the grain structure is consistent. On my first attempt I used local spruce and had one side fail due to a spot of twisty grain. I suspected it might be problematic and, of course, it was! I decided to take no chances with the nicer Sitka spruce pieces I used on round 2.
I tapered my inwales to about 1/4" in width at the stem which I assume makes them more flexible, but at the same time perhaps more fragile.
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