Q. I use a TIG welder for Steel and Aluminum racing car fabrication; mostly wishbones in steel and sheetalloy for tanks etc. I very occasionally may have to repair alloy castings. I currently have a 375 amp sine wave machine, which I have never used more than 250 amps of the output. I find it extremely difficult to produce neat welds in thin aluminum (1.2 or 1.6 mm). I have been told that a squarewave machine with a pulser would make welding this material easier, is this so? And what would you recommend? (Submitted by: Stuart Giles from Dartford, United Kingdom)


A. The problem with sinusoidal output type machines is that they cross the zero axis from Electrode Positive to Electrode Negative so slow. The arc wants to wander, flutter and is hard to stabilize. The Squarewave units like our Syncrowave series are much better for low end TIG work and our Dynasty is simply the best TIG unit on the market with variable frequency added to its arsenal! The variable frequency allows you to pinpoint the arc where you need it. The machine you are using is fixed at the frequency of the AC input power. This also makes welding thin material harder as the low frequency (50/60hz) gives a wider arc width. In this case "Wider is NOT better"