Was messing around with bow drill the other day (I usually do hand drill but wanted to practice something different). I am constantly trying out different materials to see what I can make work for my area. For the bow drill set I did a bear grass spindle on a sotol stalk hearth board. Now sotol stalk is VERY soft. Really more of a hard pith than a soft wood, but I figured I'd give it a try. Well it worked, but the really cool thing happened afterwards. There was quite a lot of wind that day. I left my ember in the notch to snap a pic and after i noticed my hearth board had essentially turned into a coal extender. The next day I was curious if I could replicate the results I had with the sotol stalk hearth board while doing hand drill. I achieved the ember easily, and as there was no wind that day, leaving the ember in the notch I knelt down and gently blew on the ember. The results were duplicated! So, sotol is not only a decent hearth board for those in the Southwest, but you can easily use it as a coal extender if your tinder happens to be marginal. Southwest Friction Fire Tip! Have fun guys!