With the continued development of new materials and equipment, many old skills are fading away. Brazing is becoming one such lost art, but sometimes it is just what the doctor ordered on either the racecar or support equipment. So here is another winter shop tip.
When brazing, I find it's best to use a slightly "carburizing" flame, rather than a neutral flame. Depending on the size tip you have on your torch it may require different oxy & acetylene pressures, so instead of pressures I use the following procedure to set my flame:
Start with both regulators backed off (counter clockwise) until they turn freely. Have the acetylene bottle valve opened 1/2 turn and oxygen tank valve opened all the way.
Then on the torch handle, open the acetylene knob 1 turn and have your striker handy. Slowly turn the acetylene regulator in (clockwise) until the gas starts to flow and then light the torch. Adjust the acetylene regulator until the flame has about a 1/4 inch gap between the torch tip and the base of the flame. This is now the proper pressure for the size tip you are using.
Next, open the oxygen knob on the handle 1 turn. Then start turning the oxygen regulator clockwise. Watch the flame as you increase the oxygen flow and adjust until the inner cone in the flame has just become clean and sharp edged. This is a neutral flame. Finally, I close the oxy knob on the handle just enough to get some feathering extending slightly past the inner cone. This is the carburizing flame that I find works well with brazing. Of course, surface prep and other factors will have an impact on your job, but getting the proper flame will go a long way to restoring this fading skill.
