MIG Welding: How to Set Voltage and Wire Feed
Kevin Caron: A question I?m often asked is: ?how do you set the dials on the MIG welder? Where do you start? How do you know where to set it for a piece of 16-gauge metal versus a piece of quarter-inch metal??
Let?s begin using the 251 Miller. The Miller Company was nice enough to give a chart with rough settings so we know where to start from. You can probably find this information on the Miller web site.
The chart asks you, ?What are you welding?? If it?s steel; steel for outdoor, windy applications, stainless steel, or aluminum; it suggests wire type: solid core or flux core, stainless wire, aluminum wire.
As for shielding gasses - the stuff that?s in the bottle, it states 100 hundred percent. The chart spells it all out for you.
There are different wire sizes. I?m running 035 wire in this machine now, so we?ll set the machine accordingly. Next it shows different sizes of metal, from half-inch down to 22-gauge. I?m using a piece of 16-gauge metal. We?re running 035, with a mixed gas - , so it?s 75 percent argon, 25 percent carbon dioxide.
We know we want to start with about 16 amps and about 165 on the wire. We?ll set it up and see how that works. Let?s put on our safety helmet and give it a try. Let?s run a little bead and see how the settings work.
This is the first part that I did. With big welders, such as the kind I would use when creating a large freestanding metal sculpture, a welder that utilizes an extra-long cable, you have to purge the cable first thing in the morning to get your shielding gas back up to your tip again. With that first little bit I just did, I didn?t have any shielding gas. That?s why it sounded different and made a little bit of a mess.
Then I started over and put a bead down, and it worked just fine, because I had gas. Looking at the weld, you can see the weld turned out really nice. It?s flat, smooth, and there are no big gaps in it.
But you can see it?s a little lumped up; kind of tall where it didn?t get a lot of penetration. That?s because either the wire feed was a little too fast or the amperage was a little too low, or maybe I just moved a little too quickly.
Let me adjust the controls. I?ll turn the amperage down a little and turn the wire feed up a little, way out of proportion, just so you can see the difference. You have to get the feel of what you?re doing all the time.
Those gross settings are just a starting point, but you really have to take into account the metal that you?re working on; how thick it is, whether it?s clean, or dirty; or whether you?re indoors or outdoors. These are all different things that you have to keep in mind as you?re working. And you have to make necessary changes as you?re working. It?s really something you learn over years of experience.
Now I?ve turned the amperage down to 14.7 and I turned the wire feed up to 200. Put your helmet back on and let?s see what happens now. That makes a mess; it means it?s too cold and the wire?s too fast.
Did you hear it hop, skip and pop in the middle of the weld? That?s because the wire?s coming out so fast you can?t get a steady bead going. Let me turn the controls the other way now and we?ll see the difference.
We?re now up to 18 volts and only 135 on the wire feed, lots of amperage and very little wire. See the difference? This is pretty good. The weld is a little high here where I may have been moving a little too fast, but this was starting to sink down in where I slowed down - that?s where the extra amperage was coming in; the extra voltage, where it?s starting to penetrate into the metal.
You can hear the difference in the sound. More like bacon sizzling rather than firecrackers going off. That?s how it works. You?ve got to play with it, practice with it. Keep trying. You?ll get there.
Incidentally, I didn?t learn this in school. I?m self-taught, not a professional in any shape or form. Take everything that I say on this how-to video with a grain of salt. This is all welding stuff I?ve taught myself how to do here in my studio. If it?s wrong, I apologize. But it works for me.
Until next time?.
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