A viewer was getting back into welding. He knew how to stick weld (arc weld), he knew how to MIG weld and TIG weld somewhat. But he was trying to make a cold air intake for his pickup and wanted to weld some really thin aluminum pipe.
He said the biggest challenge is trying to hold the pieces of pipe in just the right spot and tack weld them together. He just doesn’t have enough hands.
How do you tack weld really thin aluminum without using filler rod? It comes down to settings on the machine. Once you get your welder set up correctly, it should be pretty quick and easy.
Kevin has a couple of flat sheets of 16 gauge aluminum. He is suspending them on some metal bars to get them up off the table and simulate welding pipe because you would have air under it.
He is running the Everlast Lightning MTS 275 multiprocess welder. Kevin has the machine set on TIG aluminum, with high frequency 4T control – that’s the finger switch on the torch. He has the welder set at .8 on the preflow, 15 on the starting amps. Pulse is off. Upslope is off – that’s important. Down slope is at 3.3, but that’s not a big deal. AC is on advanced pulse. There’s advanced AC, soft AC, triangular AC and sine wave. So it’s on advanced AC, 30% on the balance, 125 on the frequency. And that’s all you need.
Kevin is going to weld using the finger control. No foot pedal. He puts on his welding safety equipment and demonstrates how to tack weld thin aluminum using TIG welding. He tack welds the thin aluminum with 131 amps on the machine. He starts on one side, clicks the trigger. Then as soon as the arc initiates, he hops over to the other side, and clicks the trigger again to kill the arc.
Kevin shows the results. He missed 1 tack weld and blew a little hole in the metal, so he added a few more tack welds after it.
You can tack weld like this with a foot pedal instead of the finger control. Just turn your amps up a little. Kevin had his amperage set at 113, so turn your machine up to about 120 if you’re using a foot pedal. You’re going to start on one side and floor the foot pedal. The arc is going to start, then you’re going to hop to the other side. Let go of the foot pedal a second, maybe two. That’s all you need. Bam, bam! Bam, bam! And you can get those little tacks in there.
Now you can come back with your filler rod and weld the pipe all the way around.
If you don’t have a welder with 4 different waveforms on it for AC but just have a sine wave, transformer based machine, it works the same. Just turn your amps up a little higher than you think you actually would use to weld something this thin. Start on one side. Hop to the other, kill it. Quick, quick, quick. That’s the only way to do it without using a piece of filler rod that allows you to hold both hold one side against the other side.
Kevin hopes that points you in the right direction on how to do something by yourself.
Before you go, though, you might want to see Kevin play-by-play a flub ….