Keep in mind I'm still very new to Bamboo arrows. I use two heat sources, one is a propane plumbers torch with a copper pipe extender on it to help keep the flame off of the shaft (burns and too hot), the second is an oil lamp that is candle sized. I like the oil lamp because the heat is not so intense, but you end up with soot covered arrows. Most of the soot comes off with steel wool, but not completely. I'm using the propane 95% of the time now. For the nodes, Ive found that when i have a shaft that is "stepped" focus on the area right before and after the node. The node itself is usually fine. When I need to actually work a node, I rotate the node in the heat till hot to the touch, then remove it and wait till it is just below hot. Then I put it back in to reheat and work it. I think that this works better because the outside of the node is hot but the inside is not ready. If you leave it in the heat, you burn the outside, but it won't move yet. The pause lets the heat travel inwards. Sort of like a steak can be, outside black inside frozen. I've also noticed that I break most of my shafts because I push to hard. Just heat and then put small amounts of pressure on it, let the shaft "relax" into shape. When I push to hard, I can feel a few fibers break and then it cascades. I wonder if those first fibers to break are not hot enough yet and because the break the rest goes. Sort of like pulling a splinter on the back of a bow. Oh and really turn down the gas on the torch, I adjust the flame by sound. I've also noticed that if you can sand the node down to match the shaft, they move better. I use a 1 X 42" belt sander. Again, I'm new. keep it in mind.
Swamp