Spot welders offer a controlled burst of welding to connect two pieces of metal. “It’s like a tack,” says Kevin. It’s a good strong tack, a repeatable weld to hold pieces metal together over a long distance. It’s much more controlled than adding a little filler, adding a little filler, adding a little filler.
On the control panel of the 250EX, Kevin goes to the spot weld timer section and pushes the spot welder button to “on.” The welder shifts the 2T / 4T function to 2T automatically.
Kevin says the spot welder seems to like to run a little hotter than if you are just welding. Usually, you’d run the1/8″ cold rolled plate steel he is using at 125 – 128 amps, but for spot welding, he sets it to 140.
The green knob in the spot welding controls is the timer. It runs from 0 to 10 seconds. He’s set it at about 1-1/2 seconds. He’ll start welding and make adjustments as needed.
Kevin has set up an aluminum billet he’s machined to make it square and placed one piece of metal on the top, which he is holding with Strong Hand Tool’s “grasshopper” tool, and clamped another piece of steel to the side.
He’s going to tack the corners, then draw some lines and spot weld the two pieces of metal there.
He puts on his safety gear and fires up the TIG welder. Kevin makes the first corner tack, checks it, then tacks the other corner. Then he draws three lines. He positions his tungsten at each, pulls the trigger, and lets the spot welder determine how long to run for each tack. Each time, he pulls the trigger, then the machine shuts off.
Looking at each weld, the spot weld timer may have been set a little high, so while welding he had turned down the timer and turned up the amperage, balancing out the two. The second round of welds showed less heat distortion. All the welds held well, however.
Kevin wants to play more with this feature, but so far he likes it.
He hopes that points you the right direction. He’s going to get out of his welding gear and get a cool glass of water, but you might want to hang around for another moment to help him find something he’s lost ….