Unfortunately there is irony in your handle as red oak board bows are predictable in that they will almost always eventually crack. Does the crack run up and down with the grain, or sideways against it? if it runs with the grain, you may be able to get a little more life out of it by wrapping it with a f/g patch. if it is against the grain I'd call it a loss. Either way, I'd get a good hickory, elm or osage stave and get started on a stave bow. They will outlast a board bow and look much better! best of luck! no sense stopping with one bow anyhow! No need to power tool when building primitive bows anyhow. welcome to the addiction. You break one you build one!