i recently cut down a nice looking and straight walnut tree about 6-8 inches in diamter. i hand split it and found the heartwood not exactly straight, sort of a very long stretched out s-shape. the heartwood covers about 5 inches across of the split wood and is uniform in width all the way down the log. i hope this is making some sense. my question is this--do i shave all the whitewood down to the heartwood before i start working the wood into a bow or can i use both the whitewood and the heartwood seperately or save some of the whitewood for backing of the heartwood? will the straightness issue be a significant factor in working the bow? any advice about working around the straightness issue?