What are your needs? Just getting started welding or experienced? What's your price range? If you would consider a 120v, you are probably not into production, but if you are considering a 220v, you are probably not looking for ornamental either. Let us know what your plans are.
I've been thinking about upgrading to a new welder so mine could be for sale. It's an older Hobart 250 beta. Welds 1/2 inch in a single pass, although I think its rated at only 1/4. My setting are always lower than what the tag recommends. It has built many items for many people on here. I have been told that repair parts are getting harder to find, but doable. In all honestly, I think it welds as good or maybe better than a lot of the new stuff out there that I have played with. If I knew I could fix it in a day or two (if it were to break) I would keep it forever. I do a lot of projects for customers and don't want to get stuck in the middle of one with a broken welder that could be down for a while waiting on parts. If the chance of down time doesn't scare you, this may be a good one for you. As of right now it works perfect. Still thinking about a price, but I don't think I would sell for less than $600.
