How much are you looking to spend? And what are you wanting to do with it?
Ideally, I'd like to have a power source like Lincoln's square wave 450 which I got to use at school last winter. It could be switched back and forth from stick to TIG easily, and I think it was wire feed capable as well. Its also several thousand bucks :grumpy: I get into a lot of metal working projects besides knifemaking though.
Right now I just have a Lincoln AC 225 stick welder(actually its my dad's). Its done everything I need in terms of work around the farm here repairing things, and I've done some pretty good fabricating with it too. Its not something you do anything really intricate with, and is only able to weld steel as its AC only. If you get one thats AC/DC you get a little bit more versatility (can weld some aluminum). Its about the most bang for the buck you can get in a welder in terms of duty rating, and you can weld a really wide range of stuff with them with practice. I've welded stuff well under 1/8" clear up to 1/2" and thicker with one.
The advantage of a GMAW/
FCAW (wire feed) welder is no stopping to change electrodes in the middle of a weld, and the ability to weld thin stuff. If your planning on large projects with long welds, this is the way to go since you can run continuous beads. The problem is that one with a duty cycle capable of taking on those large projects is going to set you back over $1000 (best deal I've found so far is the Hobart Ironman 210). The smaller ones can do quite a bit, but generally aren't rated to be run hard for more than a couple minutes at a time. They are very versatile though, you can basically get stick welder performance using fluxcore wire, but no hassle of stopping for a new stick....or you can use shielding gas and get super clean welds with no slag or spatter. Can weld sheet metal also, which is pretty much impossible with a stick welder.
TIG is my favorite of all of them, but they're awful expensive and not something you use alot in general fabricating type stuff. You can weld just about anything with them, thin or thick, steel or aluminum. You get super clean welds, and have more control than any of the other types of welders. Running one will really show you what welding is supposed to be. Most people think its the most difficult to learn though (I picked it up a lot easier than stick...go figure) Its main advantage is appearance of the welds, and the control. Its what you want if your making really detailed stuff that has to look perfect. For general shop use though, the extra expense and learning curve don't make it the best choice.
Oxy Acetylene is fun, but I wouldn't buy that as my only welder. I've used it for 14 gauge sheet metal a few times and it works great, but is a little bit slower than some of the other methods. You also have the hassle of lighting and tuning the torch everytime you want to start another bead, and you have to learn how to use filler metal if you want to get into anything too serious (which ups the learning curve). Its a very versatile tool since you can also cut, braze, heat treat etc. with it.Another thing I plan on buying someday. I wouldn't buy one with the intention of doing a lot of welding with it though.
For someone just wanting a general purpose welder in their shop, I'd probably recommend one of the small-medium wire feed welders. Hobarts Handler 140 looks pretty neat, and Lincoln has a similar one (pro 175?) thats real nice too. I can't remember the model because no one local carries it :grumpy: They don't cost too much more than a good stick welder, and have great versatility. They're also probably the easiest welder to learn how to use. If your wanting to weld thick stuff on a budget, you've got to go with a stick welder though. I've grown pretty fond of mine after some practice anyway
Most guys here who only have one welder seem to have a wire feed of some sort and all seem pretty fond of them. I'd like to have one too, but I'm holding out until I can afford a big one
We've had a few threads on topics like this