The Basics of MIG Welding

The Basics of MIG Welding

Whether you are using the process in your shop, on the field or in your hobby unit, MIG welding is an excellent process which is also a very easy process to learn. MIG welding came into existence during WW-II and the process helped to produce equipment and weapons faster. After the war, the process started being used in factories and shops.

What Is MIG Welding?

In the case of stick welding, the flux present on the electrode melts and a gas is formed which shields the weld puddle from the atmosphere, which has oxygen, nitrogen, hydrogen and other gases that will create defects in the weld if they come in contact with the weld pool.

MIG welding essentially is metal inert gas welding and in MIG welding a solid wire made of steel is fed from the welding machine via a liner and through the contact tip of the gun. When the trigger of the gun is pulled, the contact tip of the welding gun becomes electrically charged or hot and melts the wire forming the weld pool. This can occur in many ways.

Short-Circuit Welding

In the case of short-circuit welding, when heated, small drops of molten wire flow to form a weld puddle as they come in contact with the base metal. An inert gas flow through the welding gun, which keeps the puddle from the atmosphere. The gas used for the process is usually an inert gas such as argon or helium which will not combine with any other element.

GMAW (Gas Metal Arc Welding)

It was discovered later that carbon dioxide, which is not an inert gas can also be used for welding and since CO2 is not an inert gas, the process could no longer be called MIG and so it was named GMAW. Although GMAW is still sometimes referred to as MIG.

Automatic and Semi-Automatic MIG Welding

MIG welding can be done both automatically, as well as semi-automatically. An instance of automatic MIG welding is when a robotic arm welds car frames in an automotive assembly and semi-automatic MIG welding is when the MIG gun is operated by a welder, who controls the weld pool. In the case of automatic MIG welding, the operator sets up the process and monitors the machine without intervening manually.

Advantages of MIG Welding

MIG welding has many benefits such as it is a very easy process that can be learned easily and produces very good-looking welds. There is almost no clean up required when using MIG welding. You can weld on several materials like stainless steel, aluminium and mild steel and the welding can be done in all positions. You can get high productivity with MIG welding as you don’t have to stop frequently to change the rods or chip and brush the weld often.

Disadvantages of MIG Welding

Some of the drawbacks of MIG welding is that you need a bottle of shielding gas while welding, which can be quite cumbersome. The consumables for welding such as nozzles and tips cost a lot of money. MIG welding is not effective on dirty, painted and rusted surfaces and it may not be effective for thick steel as you will not be able to get proper penetration.

MIG welding is a popular and easy process which can be learned very easily. It is very versatile and can be used for different types of projects as the learning curve for MIG welding is not very steep. The best part is that you can easily set up a MIG welding unit and start welding.

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