It's funny as you see a lot very expensive contraptions being use when simple air/ pressure and gas mix is all that is needed. Most of this can be done by just moving stuff around. I used to be precise a converted plumbers torch to start with which worked fine. The trouble was not enough air could mix and i set the latest incarnation up to do some trial and error testing. the problem was that it took 2 minutes to find the optimum and left it as is. I go through a lot more disposable crucibles (stainless steel canisters) now only lasting no more that 3 melts but these do last longer than steel pipe.