Newbie welder here. I really like your forum and I hope I can draw from what looks to be a lot of experience to help me with some undocumented questions for my welder. I have a MuscleMig MM140SL and it appears to be a solid built 140 Amp MIG, but my question is about its abilities to TIG. Snap-On sells their FLEXTIG attachment for it, and 4 of the 12 settings on the "clicker" type amp range selector dial are designated for TIG. My biggest concern is how are you going to TIG on what's basically a Constant Voltage power supply. I know that some of the upper end name brand power supplies are selectable to use as either constant current or constant voltage, but I've been able to find no documentation to say this maching really does that. I've searched threads here and only real comment I found was "it doesn't feel like your usual TIG." Best I can figure is that if the power supply is only constant voltage, that you're going to have to hold the torch to work distance REALLY steady in order to keep the heat constant. The other issue is the FLEXTIG kit comes with no foot pedal, only a locking on/off switch built into the torch handle. Seems like you're pulling the trigger and getting full power right away. Not a great way to start and stop a bead. Since Snap-On markets primarily to automotive markets, you'd think if they were giving you TIG abilities, it would be for car body panel type work. This doesn't sound like enough finesse for doing light gauge sheet metal welds.
There is definitely no HF, the manual says it's scratch start, and in bold letters says THIS MACHINE WILL NOT WELD ALUMINUM. I'd pondered on adding an HF box like maybe a Miller HF-251D-1 and I think that might be possible to rig up, but there doesn't seem to be a way to work in the foot pedal since the amp selector is a click type selector, not a rheostat type. (and I looked inside and there are 12 individual wires all going into the main transformer), so I'm not sure it'd be worth it.
So I'd like to hear other people's thoughts, especially from those who've used one. Is it something that I'm gonna be forever cussing? Can it go low enough on the power to do car body panel work. And the million dollar question, does anyone have one and LIKE it. I definitely wouldn't have bought it just for TIG. I was shopping for a Snap-On tool box and the guy MADE me buy it with his box, ok he didn't twist my arm, but he made the deal so sweet I couldn't turn it down. He was about to lose his whole storage unit full of tools if he didn't raise some cash to pay off his back rent and I wanted to help him.
My thoughts are not to venture down this Snap-On FLEXTIG road. I have another couple of options. I've read enough to realize that I probably wouldn't be happy long term with a Miller Econotig, but I'm basically a small-time automotive repair shop and I want to have some welding capabilities to set me apart from other shops, and I'm just starting out, so I'm on a budget. I plan on using it in the shop, so being mobile isn't an issue. I've got a local Econotig available that the guy has offered to me for $500 with everything but the bottle. Other option - I found an older Dialarc (not HF, bare box, no leads) on auction that I might can get for $150. I also found a Miller HF-251D that the guy is selling with torch and foot pedal for $350 that I could pair up with the Dialarc. Both those options are going to be around $500. I have an old Chemetron 225 straight AC machine for sticking that I can use the leads from on the Dialarc, then let the Chemtron go and get a few dollars back (lol not much). I know the Dialarc weighs a ton, but it would give me more power if I wanted later. I understand a 50A breaker for it would probably work fine for as much as I'd push it. Which of these options would be better on lighter gauge body work? I could get into some exhaust or header work later.
Thanks for your help! Bill