Newcomer to Mig Welding?

Starting out with MIG

I was inspired to write a post about getting started with Mig welding, also known as Gas Metal Arc Welding (GMAW), when I was talking with a friend of mine about his welding woes.

My friend just purchased a Lincoln Electric PowerMig 140C and was having problems with the weld being "cold" and getting a "ropey" weld bead. After providing some feedback and insight I figured that more people in the hobby welding segment would benefit from these few points on "Starting out with Mig"

When first purchasing a welder, you need to keep in mind your application. What type of material are you going to be welding on (stainless, mild steel, aluminum)? What is your maximum thickness of material(thin sheetmetal,up to 1")? What is your input power (120V,230V,460V?) Where will you be welding (small garage,outside)? These are important considerations that are easily overlooked when people first purchase a Mig welder.

One of the more popular welding machines on the market right now for hobby welders is Lincoln Electric's Power Mig 140C. The 140 stands for the maximum current output of the machine, and the C stands for a continuous voltage selection. The 140T model is a tapped voltage selection. The advantage of the C model is a user can hone in and fine tune their voltage.

Back to my friend. He was having problems with his bead running "cold". I had a few helpful suggestions for him. First, I asked him what type of circuit he was running on. This is important because most home circuits are 15A 120V. This machine and other small Mig machines may require a higher amperage circuit. The 140C requires a 20A circuit. If you are operating on a lower amperage circuit, be aware that you will not get the full capability of the machine's output.

The second suggestion I had as well was to flip the inside panel up on the machine, preferably with the machine off. Inside the panel is a chart of material thickness corresponding to voltage and wire feed speed (which is synonymous with current). These settings will help the user get a closer "ballpark" setting for their type of weldment.

Next, I asked him what type of consumable he was using. Turns out he was using Lincoln's Innershield 211-MP. It is important to know what type of consumable you are using because polarity is everything! The PowerMig 140C is shipped with its polarity on (DC-) . If you are Mig welding with solid wire and using a shielding gas, then you will need to change the polarity on your machine. This is a detail that is frequently overlooked! See image below to understand a little better.

Lastly, I steered my friend to look at the consumable literature for the type of electrode he was using. I actually sent him the Innershield Welding guide (provided by Lincoln Electric) as well as the literature on Innershield 211-MP. These documents provide vital information on recommended settings and material thickness specifications, code requirements...etc.

In closing, always remember to look through the operator's manual for more detail on the working of the machine. It is also important to always practice safe welding procedures and protocol. For Lincoln machines, you can always find the necessary information at www.lincolnelectric.com