How to Weld Thin Metal With the New AlphaMIG 250 MIG Welder / Arc Welder
A viewer, Mike, watched Kevin's recent how-to video in which he welded some 1/2" steel with AHP's AlphaMIG 250 and said, it's great it can weld at 30 volts, but how does this machine do with thin metal?
Kevin has set up some .047 mild steel, which is about 18 gauge. He has .30 wire in the machine and a nice air gap under the steel so his thick metal welding table doesn't sink the heat away - he wants all the MIG welder's heat to go right into that 18 gauge metal.
He sets the machine to 141 inches per minute of wirefeed, 17.6 volts, 2T and the MIG setting. He just needs to turn on the welding gas and grab his helmet.
First he tacks the thin steel at the front and back of the section he's welding, then he runs a long bead down the middle of the metal.
Afterward, Kevin says, "Boy, back to school for me!" He shows the piece of steel he just welded, with the tack welds. He had seen the welding wire skip a couple of times, so he may not have the drive roller tension set right. He shows where it skipped and where he burned through - "That's operator error," he admits, also noting that the welder voltage may have been set a little too warm - you can see where the weld came right through the metal.
Next he shows the test piece he did before he began videotaping on which he'd welded a small section at 15 volts, one at 16 volts, and another at 17.9 volts. On the back, you can see how each of those sections look. "That's why I turned down the voltage a little bit from 17.9 volts," he explains. But he also had that wirefeed hiccup, too.
What did he mean by "drive roller tension"? Kevin opens the MIG welder and shows the drive rollers. They are set on the right size grooves for the wire, but then he notices that the two drive roller adjusters were set differently: one was above 3 while the other was at 2-1/2. He turns them both to 3. That pushes down on the upper assembly, which pushes down on the upper drive roller, which helps pinch the welding wire to the lower roller, and helps push it better. That should fix that little hiccup in the weld.
But first you might see the kind of thing that is, for obvious reasons, usually cut out of the videos ....
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