The unit is water-cooled, but he said that if you are just using it here and there, you don't need to hook it up.
Do I need it? Well, like I said, I always wanted to learn to weld, because a couple of my friends do it, and it just seems so convenient to be able to fix things that break, create new wierd tools, etc. I have all kinds ofideas for things floating aroudn in my head, and it would be nice to be able to actually create them. Every time I need something, I have to go to someone else, and either ask for a favor, or pay for it. Kind of like my pickup. I got tired of always bugging my friends to use their trucks, so I went out and bought a cheap, $900 4x4. I only use it maybe 1 or 2 times a month, but it's there when I need it, and I don't have to depend on anyone else. I'm not a bodyman, and never will be, but I though it would be nice to get good enough to replace panels, do patches, etc on my own vehicles in order to save money.
I don't really know what all of the different types of welders are good for. Along the way, I guess I kind of got the impression that there is some type of pecking order going from worst to best: 1. Torch welding, 2. Arc welding, 3. MIG welding, 4. TIG welding. Since this is a TIG welder, I just figured it would be the most versatile (Again, my own, demented impression). Seems to me, though, that most of you guys are leaning toward the MIG as the all-around unit of choice.