Thanks Dave. The rind is removed, but after I posted I watched on Dave's sight break a limb ,and build an other one, and he did use a fine hack saw blade to rough the back. I should have just ask you before starting. I have sinew backed quite a few bows ,but never bamboo. I used tb3, so maybe it will work .Thanks for your reply. Your are willing to help people on here, and you build excellent bows.