The Metal Inert Gas or MIG welder has been developed since the 1940s and has become the choice way to weld. It uses a procedure called gas metal arc welding (GMAW). It is a reliably simple process. It uses a welding gun to control the feeding of a wire, also known as the electrode, and distributes a stream of inert or semi inert gas over the join to protect the process.
These days the most common gas to be used is the semi inert gas known as carbon dioxide as this is check and works effectively on most metals. Gases such as argon is also used when working on metals such as aluminum as it produces fewer splatters, giving a better finish.
The GMAW process has many more benefits compared with other types of processes. One of these advantages is that the gun has a trigger to control the electrode, allowing you to have more control and position the tip without the danger of striking an arc by accident. Once it is in the place you want, all you have to do is flip down your helmet and pull the trigger.
The shielding gases which are either inert (for a better result) or semi inert (cheaper) are used to protect the join and smooth and clean the joins. That way there is no need to clean off any slag. The process also allows work to be performed at reduced amps, so it can be used for thinner metals and sheet metal. A DC current is always used for this as using alternating currents does not provide a steady arc reducing the effectiveness of the job.
It also lets you adjust the amps, the voltage and the wire feed speed allowing you to have total control over the weld result. There is a valve on the handle that can control the flow of gas as well.
If you want you can also use a MIG welder even without the gas to shield the join. The process is called flux cored arc welding (FCAW). This process uses a wire that has a hollow core that is filled with flux to produce a clean join. This allows you to work outdoors as you dont need the shielding gas. As a result, the flux core wire is hotter and can be used for thicker joins. A resulting problem is that you will need to clean the slag from the join.
MIG welders are used to join tin, zinc, copper, aluminum, tin, brass and steel. There are also a lot of different configurations of MIG welding wires to choose from. It allows you to get the best combination for almost any situation. If you are on a limited budget and only want to purchase one welder and still be able to work on a variety of metals, the MIG welder is seen by many as the best one to go with.