quadnie

You're pretty much on the right track.

Yes, a regular old wire feed welder uses flux cored wire, which means that the wire isn't solid, it's made up of two parts. An arc welder uses sticks that aren't one material, it's basicly the welding material bonded with something to hold it together.

A Mig = Metal Inert Gas uses solid wire and requires shielding gas. Either straight carbondioxide or argon/co2 mixture. What the gas does is create a zero oxygen atmosphere within the immediate welding area so the metal won't oxidize. That is how you can do stainless and aluminum and such. Another advantage is the shielding gas cools the metal while you are welding so it makes exhaust work easier.. try doing exhaust on an arc welder (messy!).

There is a science to welding that most people don't realize, they think of just pressing the trigger and going, there is a lot more too it like continuity and metalurgy.

-ryan