The local community college offers some metalworking classes through the local high school at night. I took the general metalworking class last semester, and this time I'm taking the welding class. It really takes both to get anything done. One side has the cutters, benders, punches, drill presses, lathe and milling machines. The other side is where you stick the pieces together. So far we've done gas, MIG and we just started stick last week.
I really like gas welding (acetylene), and I'm really good at it, but its slow as heck, and dabbing the rod into the puddle is an imprecise and messy task. Plus, even with a #2 tip, we were still only joining 14 gauge steel plate (pretty thin stuff).
So next was MIG, which is welding made easy. The machine does everything for you. All you do is press the trigger and the electricity turns on, the gas comes out (unless you're doing flux core), and the wire starts feeding into your work. The electricity heats up the wire when it touches the plate and it melts it. That's about it. You can have the tip really close to your work, or pull it off a bit (or even a lot), and it still pretty much works.
That's not to say you can't screw it up. If your power is too high, you just melt through the metal, instead of welding to it. But you have the same problem with gas if your flame is too hot, or you go to slow. If the wire feed rate is too high, you tend to pogo stick a little, but its an easy fix; and if its too slow it can stutter, but that's pretty obvious too (instead of the consistent BZZZZZZ sound, you get it going BZAP-BAP-BAP-BAP). Ok, so one time I welded the wire to the tip and had to take the gun apart and replace the tip, but now I know better, so that's won't happen again.
The good thing about MIG (besides being easy), is its fast. It really lays down filler, and any type of electric welding (MIG/ARC/TIG) heats up the metal much faster than gas (and also produces one heck of a light, you're talking a #10 or #11 helmet with full UV protection, vs some lightweight #5 goggles for gas). Unfortunately, you've got to move fast to keep up with it, and if you're not smooth, the results aren't pretty. That's kind of where I'm at with it. Under ideal conditions I can do pretty good, but in the real world things are still a little rough.
So when I found out that this coming week was spring break and we wouldn't be having class (sad), I asked if I could borrow a MIG unit from the loaner pool. So now I have a MIG unit all week (happy happy, fun fun), though its flux core which is a bit messy. Hey, its for practicing anyways. Its just an old cricket 130, not quite as nice as this unit:
but its managed to melt everything I've tried so far. Lesson 1: you cannot weld thin sheet metal. You can however cut sheet metal with a MIG welder, though its probably not recommended. I think the hardest part is going to be finding enough scrap to keep busy with.
After this week, its back to ARC (SMAW) welding which involves holding a 14-16" welding rod on one end, while trying to keep the other end on the work piece while it blasts a hole through the steel leaving a puddle its its wake. Then there's trying to keep all the different rod types straight: 6013, 7018, 6011, 7024, 8010, etc. And these machines sure have a lot of dials on them:
