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!

Welding Supplies on Sale

Need some MIG welding supplies or accessories? Check out what’s new and look for product promotions going on now at Baker’s Gas and Welding.

Related Products

Miller Millermatic MIG Welder

Miller Millermatic 211 MIG Welder w/ Advanced Auto Set/Cyl Rack

SKU: MIL951603

ESAB Rebel MIG Welder

ESAB Rebel EM 215ic 120V/230V MIG Welder

SKU: ESA0558102436

Lincoln POWER MIG Welder

Lincoln POWER MIG 210 MP Multi-Process Welder

SKU: LINK3963-1

Metabo Amp Angle Grinder

Metabo WE 15-150 Quick 6″ 13.5 Amp Angle Grinder

SKU: MTA600464420


15 thoughts on “Rookie Mistakes MIG Welders Don’t Want to Make”

  1. robert malek says:

    Hobart says their 140 amp 115 v welder can do up to 1/4 steel which should be sufficient for auto frames.
    Do u disagree?

    1. Michael Miller says:

      yes. I’m a professional 4×4 fabricator. i use a millermatic 211. old one and new one. one for, 30. other for ,35. then a Hobart 115v with ,023 wire. used for sheet metal. my Hobart will not weld a 1/4 inch plate steel you pass cage inspection. i use nmy ,035 millermatic 220v for that thinness. ,30 for 1/8 and below. ,23 for 18ga and below. the amps for a 115v just don’t cut it. yes you can weld it. but penetration is gonna be low. i wouldn’t pass dye or x ray of 2i used my Hobart on 1/4 inch

  2. Clint says:

    Would you be comfortable using a Lincoln pro m ig 175 220v for 120wall tubing on a chasis

  3. Kayla says:

    Thanks for this. I am also going to ask the same thing to the welders that we’ll get. I looking for some welders to repair our fence.

  4. Felipe Elias says:

    Hi I have a Hobart 140 115v fluxs core and I just finished setting it up and it won’t weld any thoughts of what i could of done wrong????

  5. Mick says:

    I can’t even get an arc on my Mig welder. The machine barley holds the tungsten. Should I go bigger diameter. ???!

    1. Andrew says:

      First mig is a wire feed process that passes the current through the filler metal wire as its pushed through the gun. No tungsten required, that’s for tig. If your having wire feed problems 3 common things to check are the contact tip-is it clean, does it match your wire diameter? 2. Drive rollers, they typically have 2 different size grooves on them. Do they have a groove that matches your wire diameter and are they installed with that groove lined up with your wire? Also drive rollers can’t pinch the wire to hard or to loose. 3. The liner in your mig gun hose that carries your wire. Over time dust and grit collect in the liner causing to much friction causing your wire to jump and pause. Also contribute to birds nests. Easy fix, just take your contact tip off, unplug gun from machine remove wire guide tip if it’s a nice gun and blow out with shop air

  6. James says:

    I have a Lincoln Electric 100 pack ( No gas ) and I have the right wire it says it can take (.035) and for some reason the weld are not bonding to whatever I weld it to that is steel…
    What do I do and what am I doing wrong ?

  7. Chris Hemberger says:

    Mig works just fine on aluminum as long as you know what your doing. I weld .100” thick aluminum frames made for HVAC daily. Ya it’s not going to lay down a row of dimes but it will lay a solid weld. But it’s more for thicker material that a hobbies wouldn’t come across anyway, well unless they build an aluminum boat. Yes I’m a certified welder.

  8. J.T. says:

    I’m in the process of making a welding table. As I seen some made, do you recommend welding equipment and shielding gas be part of the welding table? I mean to place it as part of the w.table dolly/cart!

  9. Jennifer Mitchell-Stout says:

    I have a Lincoln MIG Pak 10. My wire feeds fine until I turn the power on the lowest setting. At the lowest power setting, the wire doesn’t feed at all. Thanks.

  10. Frank says:

    I have a Lincoln MIG-pac 140 and a friend gave me a spool of .30 wire. Can I use this wire in the wip/wand or do I need to buy a whole new wip/wand

  11. YourMomsHero says:

    For the record i am not a career welder nor do i have any certifications in welding but i know how to whip a torch a little because in my line of work the job calls for it from time to time but i do work in a car framing and safety vital components welding factory as a machine maintainance technician and here to tell you 1/8″-3/16″ wall rectangular tubing is a pretty dang stout frame. (3/16 used in superduty’s and offroad applications!!!) i have a hobart handler 140 at the house and (for my own piece of mind) ran a pass on 3/16″ and 1/4″ mild steel and that thing will eat 3/16″… 1/4″ also (if cleaned well and preheated). Then took the test pieces to work and cut every 15 mm of the bead (6 inch bead) then polished the Shit out of every cross section, etched each section with nitric acid, and put under the microscope and penetration far exceded my company’s standards on every piece in the root and in both legs. Sometimes even the “pro’s” dont know what theyre talking about. learn how to weld and your stuff will pass macros and xrays??

  12. Rick says:

    I have a Lincoln sp 100t mig welder. I use it on mild auto body steel 20g – 22g. I was able to complete a floor pan repair a couple days ago along with a couple other small jobs. When I went to weld a 20g panel a couple days later the welder won’t give me that bacon frying weld. It heats up/melts the wire and can hear the gas. I have more than half a bottle of gas, cleaned both surfaces thouroghly, tried multiple grounds on different surfaces of the car. I run .30 wire. I changed the tip while troubleshooting. Cleaned the cone of any spatter. Checked the connections for the ground cable and gun cables. Tried without the gas on and it will crackle/spatter a weld until the gas is turned back on. Any help is appreciated.

    1. Rick says:

      I cleaned the welder, adjusted the wing nut that applies pressure to the rollers and increased my wire speed by .5 and the welder is operating properly. I am going to take off the cone and tip and blow through the gun cable to clean the liner. just to take care of a little proactive maintenance.

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