BIG CHEVY 3600,
After doing a little research, it appears the unit you have is a small, inexpensive wire feed machine without gas capability. Generally speaking, your machine is a MIG welder.
It doesn't have the guts to run shielding gas, therefore, it runs flux core wire (FCAW), which generates its own form of shielding. This type of wire requires more heat input, and this is the stickler...more heat equates to more difficulty when joining thin body panels.
You can weld panels with your machine. Many folks on this site do it. It isn't the VERY best process, but it certainly isn't the worst, and it can be done.
MIG is a acronym for Metal Inert Gas. The wire is the consumable and the component the completes the electrical circuit.
TIG mean Tungsten Inert Gas. A hand held torch utilizes a small rod of Tungsten as the heat sources, and filler material must/can be added much like in oxy-acetylene welding.
You might have seen this process used on many of the TV fab shows...Jesse James, Orange County Choppers etc, etc.
TIG is more expensive to buy, and takes practice to perfect. MIG seems to be the backyard hobby standard.
For most non-technical standpoints, your machine is considered a MIG welder. Because it can't weld with a shielding gas, it isn't as desirable for welding thin body panels.
This doesn't mean it can't. There are small, specialized flux core wires made just for what you want. More folks will be along with better input, and maybe a good lead on where to find this product.
Fool around with what you have before you toss it in the scrap heap, you will be surprised.
And you thought you rambled on!
Stuart
