Mig Welding: Gas Metal Arc Welding

Mig welding is also known as wire feed welding and it is the most cost effective and efficient way to weld. It is much faster than TIG or ARC welding and it can be adapted to robots and used in high end production facilities where part after part is repetitively manufactured.

To describe it in the shortest amount of words it would sound something like this:

"It is the constant feeding of an electrode into the welding arc. The continuous feeding of the wire enables the welding arc to stay established and produce deposits of filler material otherwise known as welds.""

Some of the reasons why it is so popular today are:

1. Very easy to weld using a mig.

2. Faster and quicker process.

3. It's more economical.

4. Can be used with robots and automation.

5. Can use a shielding gas to give very smooth welding bead appearances.

6. A variety of metals can be joined.

This is also known technically as the gas metal arc welding process. This is because you can use what is called a shielding gas which will allow for far greater control of the spatter. There are quite a few different types of gases that can be used today.

The mig welding process is great because of the fact that it allows you to weld in all positions. This means you can weld overhead, vertical up, vertical down, and horizontal positions with the one machine. Not only that, but you don't have to stop all the time to change electrodes, which is what you would have to do if you were using a stick welder.

One of the biggest things going is that there is less spatter when you are using a mig welder instead of using an arc welding machine. This is especially true if you are using a solid mig welding wire or a gas assisted flux core wire (FCAW). If you use a gasless welding wire, which is commonly used for the home welder, the spatter is around about the same as that of manual metal arc welding if not a bit more.

The welding wire feed speed is adjustable by controls on the front of the machine and once it is set it will constantly hold that speed, giving you a reliable feeding wire and allow you to put down filler metal so much quicker than stick welding.

Because of the fast travel rates that are attainable with this welding process the heat affected zone (HAZ) will be much smaller. This can reduce the chances of stress fatigues and weld failures later on. This is simply because of the fact that there's less heat input and energy going into the same welded joint.

A wide variety of metals and steels can be welded using this type of machine. To give you an idea of what can be welded you can do mild steel, wear plate, high tensile steel, aluminium, stainless steel, and even a variety of exotic and specialized steels and metals.

Thick plate can be welded with ease, right down to very small thin sheet metal thicknesses such as what is used to make car bodies.

Depending on what position you're going to be welding in and depending on the thickness of the material, you can use one of three main processes. What I'm talking about here is the function, or what happens at different temperatures, wire feed speeds and heat settings.

Starting off on the lower end of the scale is the first mode you come across is what is called short circuit transfer followed by globular transfer and finally spray arc transfer mode.

These are the three main modes of mig welding all of which have different uses and applications. For the DIY welder at home you are only ever going to be using short circuit transfer mode as this is suited to small thicknesses such a sheet metal and very thin plate.