Welding ally is a whole other ball game. For a start you need to change the liner in the gun from metal to plastic. Because the ally wire is so much softer than the steel wire it tends to crumple and jam up in the liner. Commercially they use a push/pull gun. The mig pushes the wire as per normal then the gun also has a motor which pulls the wire.
You can buy a “mini spool gun” which holds a tiny spool and has a motor to feed itself. You’ll also need shielding gas (no gasless here) and you need to clean the weld surfaces just prior to welding with a stainless steel wire buff that gets used for ally only. This is to clean off the aluminium oxide which is constantly forming and which is highly refractory. It’s similar to the stuff they make the heat proof tiles on the space shuttle from.
The other thing about welding ally is that you’ll muck around trying to get the settings right, but as you adjust them and trial weld, your workpiece heats up and you need less amps. It’s even worse when you use a bit of scrap to weld on and set your welder up as it heats up a lot more than the actual workpiece so that even though it might be the same thickness the “right” setting on your scrap will probably be too low for your workpiece. I had a few goes at it when I worked in an ally boat yard and found it pretty frustrating.
Got a inverter MMA/MIG/TIG machine at work recently so will give some steel TIG a go when I get some Argon gas. Can’t do ally TIG with a DC machine and I haven’t found an AC TIG under $1K but I figure if I can master TIG on mild steel it won’t be too much of a jump from there to Ally.
Just had a thought about duty cycles. I’ve never had a welder cut out the thermal overload due to exceeding the duty cycle. I have however had a mig torch fall to pieces after bits of it melted while I was building a tow bar for my truck. I noticed the smell of hot plastic or rubber the other day when I was welding up a heap of 35mm box section for shelving. I’m guessing that I was exceeding the torch duty cycle.
At some stage down the track I’ll probably need to buy a Binzel torch or similar. At least my $300 mig has a euro connector to make the change over easy. The old CIG transmig 130 twin that I paid $1300 for 25 years ago required extensive surgery to fit another torch.