Originally Posted by oldred
It depends mostly on what you are going to do with them, a body shop would use the MIG far more than a TIG but in, for instance, a custom bike shop the TIG would get most of the usage-neither shop would use a stick very much given a better choice. For an all-around home shop welding outfit a MIG is probably going to be the most versatile for most people, key being "most people" and it depends on a person's needs-for example are you going to work most on, automotive sheetmetal or bike frames?
Almost all of my welding is with sheet metal, and I use the tig for that. It just leaves a soft weld and I can do a continuous bead, which is much quicker, stronger, and without the mig pinholes and porosity. But the most important difference for me is that I can hammer on dolly and bring the metal right back to its original shape without cracking. All the distortion comes from the weld and almost all of it can be taken out by working the weld area.
As I said before, it costs more, can't be used in some positions, and has a learning curve. I spent two weeks practicing 6 or7 hours everyday, but then I could do acceptable work, but I'm still not happy with the weld bead. I think my eyes are more to blame than anything, but for sheet metal I wouldn't even think about using the mig. I usually pull the mig out to do a spot on a temporary brace, so I can get a weak weld that is easily broken, and its easier to do that with a mig.
But like I say, I do almost all sheetmetal with a 110 tig and it fits in a small case. If I'm not using it, the only thing sitting out is the bottle.