I'm going to get shot of my old 180A MIG and SIP 140A stick welders, as they are now surplus to requirements due to the presence of various inverter machines.
Here's the MIG. It's an ancient CEA (Italian) machine that I bought from a dealer near Cambridge back in the noughties. Sometimes a bit intermittent but mostly it's been pretty good and has been good for welds up to perhaps 8mm or more.
It has a perch for a gas bottle, large enough for the Y size (303mm dia) bottles I have from BOC.
It takes reels from 5kg to perhaps 15kg, judging by the space in the wire feeder zone:
The plan is to convert it to run on flux cored / gasless wire. That way it won't be necessary for the new owner to get involved with hiring bottles of argon / CO2 mix. In essence, it requires a change in polarity from DCEP to DCEN ie the torch should be changed to negative polarity from its default of positive. Hopefully won't be difficult to do but let's find out....
Anyway, off with the cover. Yes, it's pretty old. I didn't look for date codes on the compts but I would guess 80s or so.
The black and red wires running along the bottom of the tray are the ground and torch connections. I'll want to swap those over in order to run FCW.
Bizarrely, the red wire is actually the -ve polarity and the black is +ve. Go figure. You can see this when you trace the connections back to the blue electrolytic cap. I powered it up and checked the voltage on the cap and it is indeed as marked.
The transformer is bottom left and there appears to be an inductor (the vertically wound cylinder), although it can't have much inductance as it looks to be air cored.
You can see the wire feeder at the top of the pic here. Interestingly, it is insulated from the chassis by those plastic mounts. However, note the protective earth connection at the middle left of the pic
Here's the (output) electrolytic cap. As you can see, the black wire is connected to the +ve terminal:
As confirmed with the DVM:
I've swapped the wires across. The red wire isn't reformed into a rectilinear path, as it may need to be put back later. It's aluminium, so won't take kindly to repeated bending. This was "the path of least bend".
And yes, it's now reverse polarity ("DCEN").
Covers back on, quick clean up with some Elbow Grease degreaser / cleaner.
All I need now is some flux cored wire. I won some 0.5kg reels of 0.6mm and 0.8mm in LIDL last week but discovered that the reel carrier in this machine won't accept anything less than 5kg. Doh.
Vevor sell 4.5kg reels of E71T-GS flux cored wire for £20, which is considerably less than most places - but how about paying £150 for something very similar? I should have a reel of the Vevor stuff here tomorrow....
Apart from testing its operation as a flux cored / gasless machine, that looks like a success for now. Bargain buckets!
