The instructor, Stavroula, called MIG welding the "metalworkers' hot glue gun" and it really is. The setup is this: a metal table with an electrical ground clamped one one edge. There's an electric supply that produces 18v at about 100A. And, here's the neat part: there's a spool of wire in the supply, that's fed through the hose and out the nozzle of the welder, becoming the electrode of the welder. When you pull the trigger on the nozzle the wire is fed out and is the filler material you're adding to the weld. Hold the nozzle so the electrode is about 1/4" from the metal and the spark you make is hot enough to melt the filler and the metals you're welding. The whole action and effect really is like laying down a line of hot glue. Magic!
We made votive candle holders, which is impressive to do in a 3-hour session. They're pretty simple: 5 sides of a cube, we could use the plasma cutter to decorate the sides before we weld them together, and weld the 8 edges to make the holder. We started with some practice on scrap then put everything together. I finished mine by around 4:30, and with the last 30 minutes I had time to clean up the work to remove some slag. I chose to not grind it down, because I like the effect of the patina from the welding, especially compared to the very shiny effect of grinding down the edges. Maybe painting it? Perhaps.
Anyway, it was much fun, and a lot easier than I was expecting MIG welding would be. I'm still more excited about glass flameworking than welding, but I'm enthused that it would actually be pretty easy to do some real MIG welding should the need arise.