B...did you already have finish on the bow that warped? Was it dry enough? That's a shame...it looked like a good shooter.
Swampman, ajooter, thanks!
ajooter, no, it's still bare wood. I just have this feeling that trying to straighten it with steam will kill some of its good qualities. I really like this bow. I'm going to try, anyway, and if it drops in how I like it, I'll start over again. Re. dryness, it was dry by monitored weight change. The problem is when I tillered by narrowing the tips, and it's quarter sawn, I released internal tensions. One side of the limb was originally oriented toward the bark and the other side oriented toward the heart. Taking wood off the sides destabilizes the equilibrium you had before. Black birch seems to have a high radial shrinkage differential toward the bark. I think it works fine flat sawn, but not quarter.
I'm just now trying to figure out what heat strategy I should use -- steam the handle? Steam the limb? Dry heat the limb? It's a flat bow so trying to move the limb sideways just doesn't seem like it will work without twisting it. So I'm thinking the handle, being thicker might make more sense for a sideways bend, and there it would have to be steaming.
I've seen Gordon's OS build-along handle steam bending setup, and that's probably what I'll try. Seems like altering the handle will have the least effect on performance of the limbs, and a very small amount of bend at the handle will translate to a good amount of change at the tips. Right now, the string alignment is off by about 1/2" at the one tip. The handle has not been finished shaped yet, so I can accommodate an adjustment its final alignment there if I get the tips right.
The other worry is, will the adjustment last? I feel the pressure to get a bow finished -- I don't want to hang the trade up, but if the correction works, I'll need to watch if for awhile to see if anything comes back from shooting it. Otherwise, I'll be starting a plan D bow.