I would star another. The crysals go most of the way through the oak. You can save the boo if you want to or you can go shoot the sucker till it wont shoot any more.
I don't think it will break, but the hinges will get real bad and soon it will be a 20# bow. I don't think I would back ash with boo either, maybe the hickory. What width is the boo. If it is to narrow, you might be better off to use it on Osage or some other really dense wood. Justin