Thread: Gas forge for heat treating?

My advice is simply to not overthink this. Really.
You have a large volume with some wire or a metal pipe to hold the blade, and a bit away from that you have a torch flame coming in. Charlie's one simply works by changing pressure and changing how close the flame goes into the hole.

So: enclosed space + flame = hot

I guarantee you that we didn't do many -if any- calculations. And Vic, Charlie and I all have different setups. It really doesn't matter that much. What matters most is that you get a flame in an enclosed space, and then you just play with it a bit to see where the sweet spot is, in terms of desire temperature.