I've got a Miller 212. NOT an Autoset. Back then welders were hating on automatic setting welders pretty bad. I wish I had ignored all of that and bought the autoset. Even if I would have had to adjust a little.
I'm not a welder. My good welds often look like the "bad" welds some of the guys on the welding videos do to teach us what is "good/bad."
The 212 was bought because of its aluminum capability with a spool gun, but I had hoped to MIG weld steel with it as well. I don't think I have ever gotten what I consider a good looking MIG weld for me with it. Never. I have burned a couple ten pound spools of flux core with it and made welds that won't break, but proper MIG welds seem to elude me. I've pushed enough flux core with it on a hot afternoon that it started to act flakey like it was overheating. Just like the little 110V Lincoln ProCore does after its been pushed to hard.
I'm running C25 gas. The gas is flowing. I've used the settings on the flip chart on the front of the welder, and settings all over the place besides that. I've tried varying the gas flow rate. Nothing seems to work. I've tried distances from dragging the gas shroud to way to far. Obviously I check polarity, but I tried it wrong too just to see if it would be better.
Now here is the thing. I am able to weld aluminum (100% argon) within its working range. 1/8-1/4 5052 and 6061 it does well. I can do down to .080 with what is a good (for me) weld if I take the time to use good practices, and have welded small beads super fast on pieces as thin as .043. Aluminum seems to like a little more wire feed than those listed on the chart, but its doable at chart settings. I even managed to weld some 3/8 with it with massive preheat.
Years ago in this group I discussed some of my failings as a welder, and you guys had solutions. Amazingly not all of them were just that I sucked as a welder. My big complaint back then with both my Harbor Freight wire feed and my AC Lincoln cracker box was that it would seem that I was welding along just fine, and then it would go to crap. No matter how much I tried t adjust they would just continue welding like crap. I think it was Gunner who suggested putting a cooling fan on my HF welder. It went from less than
1 inch of good weld to almost 3 inches if using .030 on 1/8 inch or thinner steel. I applied the same logic when I was welding some 6 inch well casing with the cracker box. I welded half way around and just stopped. Did something else for 20 minutes, and then welded the other half. Worked great.Somewhere along the line a friend gifted me a cheap Harbor Freight autodark hood, and I was floored with how much it help improve what I was doing. With the HF wire feed or the cracker box.
I hesitate to suggest this, but getting back to the point, I wonder if there is something wrong with the 212. I don't know what exactly though I would suspect. It welds aluminum ok. It pushes flux core ok, although I think the little Lincoln ProCore does it better (within its power range). I just can't MIG weld steel with it worth a darn. I'll admit right up front I suck as a welder, but you would think in all this time I would have stumbled across something that works good once in a while. Just straight up DCEP MIG with C25 on mild steel. Not painted. No rust. Mill scale ground away. Comfortable setup. I'm at the point of just leaving a spool of flux core in it and saying the heck with it. Even that is a pain, because I can no longer just pick up the gun I need and and go. I have to remember to swap the polarity when I swap guns.
I considered trying some C10 to see if I could spray arc with more success, but flux core is about as short circuit as you can get and I can weld with that ok. Obviously I spray arc aluminum.
I'm actually at the point where I am considering selling the 212. I just hate to stick somebody else with it if its not just me that sucks. Either that or dedicating it to just aluminum and removing the regular mig gun entirely.