**This Instructable is not intended to be THE definitive guide on MIG welding, for that you might want to seek out a a more comprehensive guide from a professional. Think of this Instructable as a guide to get you started MIG welding. Welding is a skill that needs to be developed over time, with a piece of metal in front of you and with a welding gun/torch in your hands.**
If you are interested in TIG welding, check out: How to Weld (TIG).
Step 1: Background
The heat produced by the short circuit, along with a non-reactive (hence inert) gas locally melts the metal and allows them to mix together. Once the heat is removed, the metal begins to cool and solidify, and forms a new piece of fused metal.
A few years ago the full name - Metal Inert Gas (MIG) welding was changed to Gas Metal Arc Welding (GMAW) but if you call it that most people won't know what the heck your talking about - the name MIG welding has certainly stuck.
MIG welding is useful because you can use it to weld many different types of metals: carbon steel, stainless steel, aluminum, magnesium, copper, nickel, silicon bronze and other alloys.
Here are some advantages to MIG welding:
- The ability to join a wide range of metals and thicknesses
- All-position welding capability
- A good weld bead
- A minimum of weld splatter
- Easy to learn
- MIG welding can only be used on thin to medium thick metals
- The use of an inert gas makes this type of welding less portable than arc welding which requires no external source of shielding gas
- Produces a somewhat sloppier and less controlled weld as compared to TIG (Tungsten Inert Gas Welding)