Blades,
I do all my bending with steam. I believe your problem was the limb tip thickness, since I started to work a little with staves (been all quartersawn up till now) I have found that 1" thick just dont want to bend, and if ya do manage to get some it will straighten right back out. I've been working with Ironwood, for what that's worth.
If you get your rough-out closer to finished dimensions I think your bends will be easier (on you and the wood) and will hold, at least that's been my experience so far. The higher the crown (small dia. stave) the less it wants to hold a bend. Hope that helps a little
rich