How to Weld - MIG Welding
This is a basic guide on how to weld using a metal inert gas (MIG) welder. MIG welding is the awesome process of using electricity to melt and join pieces of metal together. MIG welding is sometimes referred to as the "hot glue gun" of the welding world and is generally regarded as one of the easiest type of welding to learn.
**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.**
Step 1: Background
MIG welding was developed in the 1940's and 60 years later the general principle is still very much the same. MIG welding uses an arc of electricity to create a short circuit between a continuously fed anode (+ the wire-fed welding gun) and a cathode ( - the metal being welded).
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
Here are some disadvantages of MIG welding:
- 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)