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Rookie Mistakes MIG Welders Don’t Want to Make

Rookie MIG welders may not know all of the ways that a welding project could go wrong or a MIG machine could be set up improperly. In fact, many online welding forums are full of questions from new welders who don’t realize that most of their problems have relatively simple solutions.

We’ve reviewed some of the most common mistakes and questions that we could find and created this roundup of MIG welding tips that should save new welders a ton of time when they strike their arcs for a new welding project.

Skipping the Cleaning and Grinding

Most new welders aren’t aware of how clean they really need to make their metal work pieces before they get to work. While there’s going to be a little bit of impurity in most welds, you need to grind down the metal before you lay down a solid weld.

You can also angle your torch to keep the impurities from settling into your weld. Of course this only applies to shielded welding with a solid metal wire. If you’re welding with flux core wire, you’ll just need to clean off the flux when you’re done.

MIG Welding without a Solid Ground Clamp

If your welder is sparking and sputtering and you can’t lay down a good bead, the first thing every experienced welder suggests checking is your ground clamp. OK, may that’s not the first thing you should check every time, but using a small or poorly placed ground clamp while MIG welding will lead to a frustrating time, and it’s the easiest thing to fix.

MIG Welding the Right Materials

While a hobby welder can usually weld a variety of metals in small quantities without too much struggle, keep in mind that a MIG welder is best for steel. TIG welding often handles aluminum the best. While you can pick up a spool gun for your aluminum MIG welding projects, you may have rough going if you’re planning to make a lot of welds.

MIG Welding Thick Material with a Low-Capacity Machine

If you’re welding a metal frame that will get a lot of stress and pressure, a 115V MIG welder just isn’t going to cut it. I know you can find forum postings where welders claim their 115V MIG machines can handle more than they expected. However, don’t put yourself or anyone else in danger by trying to weld more than your machine can handle. If you don’t have enough amperage, your weld won’t get enough penetration into the weld joint in order to make a solid weld.

Check Your Polarity Settings

If you’re welding with solid wire, set your machine to reverse polarity (DCEP), but if you’re working with flux core MIG wires, you may need to use the DCEN setting. You should also experiment a little bit on some scrap metal. In fact, you should definitely practice on scrap metal if you aren’t sure which setting is correct!

Don’t Weld on Unknown Surfaces and in Confined Spaces

It doesn’t matter if you’re just making a quick weld. A spark in the wrong place could prove dangerous, if not fatal. The newspapers are full of welders who were injured or killed because they struck up an arc on top of a steel drum that, unknown to them, was filled with a flammable liquid.

You should always weld in clean, well-ventilated, dry spaces are free from flammable substances and sawdust that could smolder and catch on fire later in the day when you’re not around. Welding tables are relatively inexpensive or easy to build (maybe a welding table is the ideal first project for your new machine!).

Know What to Troubleshoot When MIG Welding

If you can’t quite figure out what’s going wrong with your weld, experiment with some common hang-ups. For instance, most new welders use too much stick out. Some experts even suggest that you should use less wire stick out than the manual typically recommends.

Of course, the perfect wire stick out won’t matter all that much if your wire speed is set too fast or too slow for your amperage, so you’ll want to check out how your amperage, speed, and technique match to your metal and the thickness of your metal work piece. Most MIG welders have helpful auto-set controls that will save you a bunch of guess work. Failing all of that, check the flow rate of your shielding gas if you’re working with solid core wire.

While technique is important, many MIG welding problems boil down to your settings. And if none of this helped, don’t be afraid to ask the pros in one of the many welding forums online!

Ed Cyzewski


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