A few years ago when I built my furnace for melting aluminium, I also built a burner to use propane. The design of the burner was a bit of a guess but it has been totally successful. It is simply a 1" tube with air holes and a 1mm jet for the gas.
What I have found though is that it works perfectly in the kiln but if I withdraw it, to use it for brazing, the flame moves away from the end of the tube and goes out. I did read somewhere that fitting a cone on the end of the tube would help. I made a very crude cone from tin plate and indeed it did the trick, albeit a very broad and ragged flame. I have lost the cone and would like to make a proper attachment for the burner to allow me to do brazing. I have made a straight tube, larger in size, that fits onto it but the flame just blows out when I try to light it. Has anybody any suggestions on what I could do to make it burn out in the open and not just in the furnace?
Thanks, Norman