billtzk said:
I see you've been reading Richard Finch's books...I like them for informative, easy reading. Anyway...
As has already been mentioned, you're looking at a $2,000+ investment for a TIG machine. I paid about $2,500 for my Lincoln SquareWave Pro unit a few years ago. It weighs almost exactly 200 lbs, so it's not really that portable. I've been very happy with it, but if I had it to do over, I'd have bought a Miller machine. Every welding professional with whom I've spoken recommends them 100% over Lincoln for ease of use and quality parts.
I have zero experience with inverter TIG machines, and no one I know uses one. I'm not sure if that's good or bad, but it seems a little on the negative side to me. I do know that many of the inexpensive machines don't have a high frequency module for arc ignition, so you have to "scratch start" - a troublesome technique that can easily contaminate your weld.
Avoid simple arc welders, AKA "buzz boxes" or "stick welders" Sure, they're cheap, but unless you're repairing farm machinery or doing heavy industrial work, they're nearly useless. You'll never get a good weld (for homebrewing) on stainless or aluminum with a stick welder. The only homebrewing application I can think of for a stick welder would be in welding a brew sculpture.
It sounds like your budget is really geared more toward a MIG unit. I own a Lincoln SP135+. It's VERY portable (~50 lbs), runs on standard 120VAC house current (you'll be lucky to find a TIG machine that doesn't require high amp 220VAC service), will lay a decent bead on properly prepared 3/16" plate steel in a single pass, and cost somewhere in the neighborhood of $500. Again, I'd rather own a similar sized Miller machine since most of them are a bit richer in features, but this one has served me well. I even had it shipped over to Korea and did some repair work (and/or customization) in a parking lot!
MIG welding is generally considered the easiest of the welding processes to learn. You simply set the machine up for the material you're welding, touch the protruding filler wire to your work, squeeze the trigger, and move the torch in the direction of the weld. With an hour's worth of practice, nearly anyone can lay a decent bead on mild steel. It's not too tough to MIG weld stainless, it'll just take a little more practice than welding mild steel, and you'll need to back gas or use flux on the backside of the weld to protect it. You can even MIG aluminum if you accessorize properly. If slag free welds aren't necessary, you don't even need to bring a shielding gas bottle to the job - you can just use flux core wire.
Whew...that was a lot of typing. To sum it up, I recommend a small MIG unit like the one I have. Feel free to ask questions, I love the subject!