MIG Welding Machines

Developed in the grim shadow of World War II – the cataclysmic time when European civilization was savaged by the ambitions of dictators, and there was a pressing need for assembly methods that would allow the fast, strong, accurate construction of thousands of aircraft, tanks, tank destroyers, artillery pieces, and small arms – the modern arc welding machine is an effective, practical device that can handle many different jobs. From the home workshop, carrying out repairs on pickup truck beds or creating metal garden art, to the mighty factories that churn out the endless metal goods used in the modern world, arc welding machines are present everywhere, and are likely be used for many decades to come.

Among the many types of welders that have been developed over the years, MIG welding machines are the easiest type of arc welder to use. Someone who has never used an arc welder before can learn the MIG technique within a few days, and start to apply it to work – whether as part of a company workforce, or independently, as a freelance welder or home enthusiast.

How a MIG welding machine operates

As with all welders, the action end of the MIG welding machine is the welding gun – the device the user holds to direct the electric arc at the welding point, and which performs several other functions that are needed for the welding process to be successful.  The welding gun operates by using an electrode to pass an electric arc into the steel, aluminum, or other metal that is being welded, which creates intense heat at the point of welding. A ‘filler metal’ is used in the process of welding the two pieces together, functioning almost like a solder, although there are many significant differences from soldering as well.

In a MIG welding machine, the electrode that melts the filler metal and the filler metal itself are the same thing. The electrode steadily melts its own tip, as well as the surfaces of the pieces being welded, to complete the weld. This process would be extremely finite – with the electrode destroying itself completely in a few moments – if not for the fact that the electrode is actually the end of a huge spool of wire contained inside the welding machine’s main body. This wire is steadily unrolled by automatic rollers, so that the electrode is replaced from behind at the same rate as its tip melts.

The hose that connects the welding gun to the main body of the welder does not simply carry this strand of wire – it also feed an inert gas like argon or a mixture of argon and helium to the nozzle. This gas blows out constantly around the welding point, keeping away the oxygen that might oxidize or rust the metal in the welding pool in a matter of an instant or two. Once the metal cools and hardens, it becomes immune to this, and the gas ensures that there is a clean, strong, high-quality weld left behind as the user moves the welding gun forward along the seam that is being  fused.
Safety issue with the MIG welding machine

Although the MIG welder is very easy to use, it should also be treated with the respect that a device based around intense heat and a steady electric current deserves. Eye protection needs to be worn to keep the retinas from being damaged by the infernal brilliance of the electric arc, while gloves are also essential. Heavy, protective clothing is also a good idea, considering that arc welders can give a “sunburn” to the skin even through some lighter ordinary clothes. Breathing the argon gas can be deadly if it manages to displace oxygen from the brain tissue, so some ventilation is prudent (although not enough to disrupt the shielding gas). The equipment should also be checked regularly for damage or wear to prevent shocks from a frayed wire or loosened connection. With a few common sense precautions, however, a MIG welding machine is one of the easiest arc welders to use for an infinity of different projects, giving a decent quality weld with a minimum of experience.