My first shooter was made from a BL selfbow. I still have it fron '92/93. I just leave the bark on but like Eric said if you remove it seal the back with poly or shellac. Ends should be sealed right away. BL looses moisture fast. Now keep in mind that the best scenario is to remove all the sapwood. BL likes heartwood backs. Also, keep in mind that the closer you get to the heartwood the stringer the sapwood layer is. So in a sapling the sapwood is pretty close so you have a good chance for success. I do think there are better choices for sapling bows like hickory, oak, maple, hop hornbeam, etc. I am not an ash man but you can add that to the list somewhere. Have fun.