MIG welding (that stands for metal inert gas) is accomplished by feeding a wire through the contact tip of a welding gun. A shield of gas, also delivered through the tip, surrounds the contact area -- protecting the electrode wire and keeping any contamination out of the weld so it looks nicer. The feeding wire is melted when it's energized with electricity and forms the weld puddle.
MIG welding is also known as GMAW (gas metal arc welding -- nowadays it can actually have some semi-inert gases like carbon dioxide in it too -- although the term MIG remains popular). The advantages to MIG-style welding is that it saves time, there's not a lot of clean-up, there's less waste and, probably most importantly, you get a really good weld.
The Millermatic 252 MIG Welder is a good example of this technology, and sells at a base price of about $2,500 [source: Miller]. Complete with wheels for easier mobility, this Millermatic can be used for light manufacturing, metal fabrication and lots of other workshop applications.
The Millermatic can weld steel, stainless steel and aluminum with a wire speed between 50 to 700 inches per minute (about 1.3 to 17.8 meters per minute). Different aspects of the welding job can be preset to save time and allow the welder control over every step of the process. For example, you can set how long the shield gas will flow before the weld arc is energized. The Millermatic also has certain memory functions, such as storing parameters and settings for the various types of welding guns you might attach to it.
We've got quite a bit of heavy equipment and materials on our hands now that's going to take up some space. Find out about a cool tool that can be used to haul all this stuff around the workshop on the next page.