Kevin addresses how to fuse weld with a TIG welder – and whether you should fuse weld at all. In fuse welding, you use your TIG torch to melt metal from each piece to join two pieces of metal together. Kevin says there are good times to fuse weld, bad times to fuse weld, and times it really doesn’t matter. He preps a piece of 1/8″ steel, removing the scale and cleaning up the edges. Then he set the metal on a “lift kit” – two pieces of steel C channel – so he doesn’t weld the steel to the table and so he doesn’t have to heat the 1″ thick steel table to weld it. He fires up his Longevity TigWeld 250 AC/DC, using the foot pedal rather than the welding torch trigger so he can control the amperage a little better. Kevin also butts the two pieces of metal tightly together instead of leaving a 1/16″ gap, as you would when welding 1/8″ plate with filler rod. He then fuse welds a tack on each side of the two pieces of steel plate, but he has to cheat on one side, using filler rod because the metal moved (this is why you clamp the metal!). He then fuse welds the two pieces of steel together across the whole joint. He explains that the joint between the two pieces of steel is weaker structurally because he has pulled metal from each piece of metal, making the joint thinner than the 1/8″ steel plate itself. Kevin then says if the weld isn’t structural – and it isn’t always structural in his artwork – it doesn’t matter as much. Also, he shows that, if he wants a nice round edge on a corner joint, fusing makes sense. If you want a nice sharp edge, though, or you are welding on the inside of a corner joint, you definitely want to use filler rod. He also suggests you play around with it, using scrap to try different welds and then hitting it on the anvil or putting it in the vise and flexing it to see how quickly the weld breaks.
