Though sometimes called by its full name, metal inert gas welding, MIG welding is a type of gas metal arc welding (which is referred to as GMAW). MIG welding is a process that is done by using an electrical current to provide an electrical arc between a wire electrode in the welding gun and the surfaces being welded. A type shielding gas is also used in order to protect the weld from gases in the air that may interfere with the strength of the weld.
MIG welding was created in the 1940’s as a way to efficiently build equipment and weapons during the second World War. It was (and still to this day is) preferred in welding shops because of how little time and skill is needed to learn how to MIG weld quickly, and also the low cost associated with it. Someone with a basic understanding of welding should be able to learn how to MIG weld and join most basic pieces with just a few hours of practice. MIG welding is also quite popular because of how little it costs – a new, quality machine for your garage costs around $500.
Now that you have a general understanding about MIG welding, I think it is time to move on to some actual MIG welding techniques. As important as background knowledge is when you are learning how to MIG weld, you need to get out in the shop and work. The following MIG welding techniques will get you on your way to creating strong, visually appealing welds.
For someone first learning how to MIG weld, the weaving pattern is probably the best starting point of the MIG welding techniques. This zigzag pattern can either be done as push (pushing the gun away from you), or pull (pulling the gun towards you), and is done exactly as it sounds. Your goal is to make even, steady weaving zigzags across the joint of the two pieces that you are welding. This is a very easy pattern to learn and become quite efficient at very quickly. Using this MIG welding technique, you would generally pause at the end of each zigzag (on the sides of the joint) for a brief second in order to help spread out the weld. The key to this is to make sure that you get a steady rhythm going when working with equally thick workpieces. Once you have become familiar with this welding design, you are ready to move on to how to MIG weld using a slightly more advanced MIG welding technique.
The next technique that like to teach is a circular pattern. For someone who is learning how to MIG weld, this technique is still relatively basic. It does take a little bit more practice and concentration than the zigzag pattern, but it is still a very achievable design. For this technique you will weld in slow, circular motions. Depending on the workpieces, and the weld you would like to make, you can either use small, precise circles, or a larger, more encompassing pattern. After a little practice with these MIG welding techniques, you be know how to MIG weld nearly any basic project that you wish to do.
While no single article can teach you all of the information you need to know about how to MIG weld, this should have been a good basis for your entry into the world of MIG Welding. For more detailed information, images, and diagrams, I strongly recommend checking out Welding Secrets Revealed. Pat, that put together that website, has been an industry-friend of mine for many years, and has helped me with quite a few questions and problems I have had over the last twenty years.
A great resource for basic welding information is the How To Weld blog.