I’m a long time advocate of narrow gap welding. The advantages are tremendous, but the challenges are too. A 5″ thick standard V Butt weld with a 75 degree included angle has five times the weld volume of a 1″ wide 5″ Square Butt. This means a narrow gap joint would have five times less weld wire, five times less arc time, much less distortion. And fewer defects because every inch of weld that you don’t make is an inch you don’t have to inspect and possibly repair.
Why isn’t narrow gap the standard technique for welding heavy sections? Because the technical challenges of welding vertical walls in confined spaces are huge. For good sidewall fusion, the arc must impinge on the walls. Otherwise, you risk lack of fusion defects at the bond line. Our new Narrow Gap Hot Wire Torch features a servo tungsten electrode oscillator to point directly at the sidewall. That is only half the battle. The wire must follow the tungsten. We did just that using a second independent servo this allows us full control of arc and the filler wire position. Finally, we use our HOT ONE AC constant voltage hotwire system to double the deposition rate, which cuts weld time in half.
To see a video including Xiris Automation Inc. arc monitoring click: https://lnkd.in/eBTHYgh