Mig welders

Anyone want to shed any light on the subject of transformer based verses inverter based mig welders? My old mig died and am now shopping for a new welder, to say welding technology has changed in the last couple decades is a mild understatement, there are now mig/stick inverter machines, three in one machines inverter based machines or the old transformer based machines that just wire weld [mig]. Some tell me in a next few years the industry is going away from the old transformer based mig's completely, the next sales guy says they'll never go away and will always be here to some extent.

There are pulse machines, arc stabilization machines for stick option on some of these machines and everything is computer controlled no matter what you buy. I was demoing a new welder and even the sales guy had to get the book out and read it to figure out what all the options on it were and to explain them and demonstrate them to me. Some of the features are nice, really nice others are something I'm not sure I'd ever use, let alone know what to do with if I had them but they come on the machines anyhow.

I have only single phase power available to my shop and we're even debating if a 250 amp machine is big enough anymore. I've looked at the larger inverter based 350 amp machines that run on single phase and those have even more options on than than the smaller one's, it almost took the sales guy a half hour to set it up so I could actually weld with it, how he did it I still don't understand, with all the modes and power settings on the machine. That was a pulse machine, with burn back settings, trigger hold setting, the ability to set the pulse widths, fine tune the wire burn in and half dozen other things I'd never heard of to fine tune a welder before.

There are copper windings based transformer machines, aluminum transformer machines, copper or aluminum inverter machines and everything imaginable out there. I can't even come to grips on the makes of machines, I don't want to start a brand debate or anything like that, just the technology that are in all the welders I'd like to have someone explain to me how it works and if any of these machines are going to last for 20 plus years like my old mig did or do I buy a new welder and just plan on tossing it in the junk pile every five to ten years and buy another new one?

Randy88 said:

Anyone want to shed any light on the subject of transformer based verses inverter based mig welders?

Click to expand...

These guys probably could... lots of reading, though... :cool2

http://weldingweb.com/

http://weldingweb.com/forumdisplay.php?6-General-Welding-Questions

http://weldingweb.com/forumdisplay.php?2-MIG-TIG-Stick-And-Oxy-Fuel-Welding&

http://weldingweb.com/forumdisplay.php?14-Manufacturer-Product-Forums&




OCR

We have a xmt 350 miller with 24a feeder and have had it for pry 5 yr and have had no problems and I really like it! it is what they call multi process so it can do stik mig air arc! there is a weld shop that is near us that has 4 or 5 of this setup for 5 or 6 yrs and they have had hardly any trouble I think they had problems with a feeder once but that it! Jerry

Know matter what any one tells you alot of the first migs ever built are still in use and alot of 5 year old migs are not. I want to buy another some day but i would pay extra not to have a computer in it.

Randy 88, I can only relate to you, my experience over the years and if the choice was mine, I would buy the inverter welder. Thirty years ago, I had a crushing plant built, which had two impact crushers on it. The chap who built it, was a backyard engineer, and a very clever one at that, he copied a design similar to the professional impact crushers of the day, but instead of using the proper manufactured breaker bars, he designed them to use railway line, which was a cheaper alternative for me at the time. The railway line bars worked well, right up until recently, when we redesigned the crushers to take breaker bars.

The only problem withe the railway iron bars, was that they had to be hard faced on the crushing edges. Like you, we only have single phase power and always struggled to get enough power out of the welder, resulting in two cooked welders. At the time, there was a mob here selling inverter welders and in those days, I had no idea what an inverter welder was. This mob were as shonky as all get out, the salesmen were all dressed up, they drove flashy cars and smelled like roses. One breezed in one day and started giving me the wind and the rain on these inverter welders, that he was selling and reckoned they were greatest thing since Adam played fullback for Jerusalem. I told him that we struggled for power and he said that would be no problem to these welders, they make more efficient use of the power and he would bring one back and demonstrate it. I thought, this will be good.

Sure enough, two weeks later, back he came with the welder, it was half the size and half the weight of the old ones, he set it up, plugged it in, and for the next hour or so, we all had a go at welding with it. Randy, if I had not seen it, I would not have believed it, that 200 amp welder, was welding to the equivalent of a 300 amp conventional welder, on a single phase plug and it welded as smooth as butter. It was a Tig/mig/stick welder and I was so impressed with it, I bought it on the spot. Twenty five years later, I still have that welder, it has been the most used and abused welder, but it still welds like it did on that first day. Continuous hard facing produces a tremendous amount of heat and a couple of times we have burnt out connections that have become dirty and built up resistance. It was branded a Strata welder, but it actually is an American built Powcon welder. I think they have been taken over, since then.

I have since bought two more inverter welders, one is actually a Chinese built one, but the agent is a chap I have been dealing with for quite a while, and he had researched these welders and found that they were performing very well. The other one is a small utility welder, that you can sling over your shoulder, but it will burn a 10 gauge rod with no effort at all. I am as equally impressed with these welders as I am with the Powcon.

So, for what it's worth, Randy, that is my experience with inverter welders.

And as they say, without a photo, it didn't happen!

Randy, I'm not sure any machine built these days will go for 20 years, be it a transformer or inverter machine. I have had good luck with inverters though, and would lean that way myself. It's pretty impressive the good experience RnR has had with his inverters. I haven't had one that long that has been treated like his, but I have a small inverter mig that is about 20 years old, and it's never given me a single problem. I now also have an XMT 304 CC/CV and a 12VS wire feeder that have been flawless for me. The Suitcase was bought new, and the 304 was a used machine from a friend's fab shop. It never had a hard life, but it wasn't babied either.

My vote would be for the inverter.........and I would make it a blue one too.....LOL

What will you be welding generally?

OCR, I spent most of yesterday on the computer reading over the sites you gave me, far more in depth that I could comprehend but great reading just the same, the jest most of them had was a transformer welder would be less maintenance and cheaper to repair if needed and the inverter welder would be lighter, have far more options and use less power and probably not last as long, now that said, since they haven't been around since the beginning of welding like transformer machines have been, that's pure speculation until more decades of data becomes available, I fully understand that point.

Old Doug, I feel the same way you do but there is not one welder sold today that doesn't have computer technology in them, circuit boards, chips, digital readout of some sort or a host of other things on them, the days of welders I've used for decades are long gone for new, used, that's a whole different set of problems and unless you know who's had it and how much its been used or how it was treated I'm going to go down that road again, it ended up costing me far more in the long run that just buying new.

Rocksnroses, that's a dead ringer to a neighbors powcon welder I first used almost 25 years ago, the nicest welder I've ever run, but back then those were almost 5k in price and everything else was under 2k, now that said I should have spent the money and bought one and maybe I'd not be in the situation I'm in today looking for another welder, but that's pure speculation and hope on my part. Powcon got bought out by miller is what I'm told, their inverter series are the old powcons that they've took to the next level and implemented is what the sales guys tell me, but the new miller inverters don't weld the same as the old powcons did in my opinion.

Valley as far as what I weld and how much I'd never really sat down and figured up till my old welder quit and was told it wasn't worth fixing and I had to live without it and did some thinking on that subject, we weld anywhere from 100-250 lbs of wire a year through it depending on what we're doing, mostly fab work and repair of steel. I haven't gotten into stainless or aluminum as of yet, but over the years there have been times if I'd had the equipment to weld with I'd probably done those too, just not much of them, what the future brings is anyone's guess. As to what thickness, its anywhere from light gauge tin to inch or better thick and everything in between. I also have an old stick welder we've been using that I put away decades ago I had to dig back out so I can weld in my shop when the mig died. I have a bobcat on my service truck we've used a lot too, but in the winter we have to leave it sit outside the shop and run the cords inside and have had a major problem with the car icing over and keeping it running, I have a 8vs wire feeder we use with that and love it, anything outside or in the wind we use that when welding, maybe another 150plus lbs a year through that machine as well besides the mig in the shop.

My first thought was to toss out the old stick welder which can die its last life any day anyhow and go buy a new stick welder now that's the shops done and buy another mig machine and go home with two welders and how hard could that be anyhow, a trip to town and do some welding on several machines and load up the ones I liked and head back home, done deal in one day. Holy cow did welding change, the different options on welders, their capability, two or three machines in one, inverter, transformer, pulse, trigger hold, stitch, spot, one, two or even three gases on one welder for different materials needs and then the brands and sizes, at the end of day one I was more confused than that when I walked in the store. Some machines I liked, others not, which is typical but the end result was I liked far more than I hated, then the debate was I could buy a bigger welder and use less power and have more than one function in a welder, I didn't need to buy two welders I could do it in one and somewhere along the line it got really complicated as to what features and options I'd use verses what are on the machines, if I had two or three welders in one would be nice till it was down and needed repairs and then I'd have no welder at all. And then there's how long will they last, which nobody seems to know, does the more features shorten the life span, meaning if I get a base welder only will it last 15 years, if I go with more options on it will that shorten its life span to 10 years and if I get the one with everything on it will it in reality last only 5 years or if one function quits, does it kill the whole welder and we pitch it in the trash or will it still weld on stick function if the mig side dies, nobody has any idea when I ask that question, the sales guys start in on the pitch of everything is available and they have the knowledge to fix it lecture and I remind them that's fine, but what does it cost once the warranty is off and the conversation ends pretty quickly and they change subjects.

I've run powcon, esab, hobart, lincoln, miller and few others I can't remember over the years in migs, and sticks are so many I can't even recall most of them but they all do the same job, putting two pieces of metal together to hold, pretty simple process or at least that's what I thought until I went welder shopping. I originally wanted another 250 amp machine due to limited to single phase power, but now they're telling me I could bump it up to 300-350 amps and still get by, would I use it, yes there are times it would be nice to have but I can do more than one pass with a 250 amp machine and be done with it. Thanks for the input guys, any and all is appreciated.

Randy I bought a miller 350p a couple of years ago Inverter of course. The funny thing is that you tell the machine what size of wire it has in it but it only goes to .045, I have never seen any .045 wire that needs 350 amps to work. That being said the duty cycle on the 350 is about 100% when welding with .045 wire. I thought I was sold on the pulse technology when I demoed my machine sales man said less smoke, better weld, cooler work pieces. Now that I have used it I would not give a squirt of pis for the pulse, but the welder works great in normal non pulse mode, pulse makes the welding process about 3 times louder, sounds like a bumble bee all the time and is very annoying. I did set down and read the manual and pretty much under stand all of the controls, I use the pre, and post gas option all the time, the welder also has a hour meter for welding time only, and keeps track of trigger pulls. I think this will be good info to have when I trade for a new one next year as they have a 3 year warranty and I will not own one out of warranty. If you don't want a inverter type machine, Systematics makes a old fashion mig welder with the tap transformer, actually that is who makes the welders for Snap-On. There is a dealer in Oskaloosa http://www.mauersupply.com/other-equipment/systematics-mp250-welder/. I am working on my 3rd Re-grouzer job this year, I use the 350 on 1 side and my 12vs suitcase on the other side I can't hardly tell a difference between the engine driven and the plug in to the wall welder. The last job was a D8 with 28'' pads we burned 125 lbs of wire on that one. As we speak we have a D6H with 30" pads in the shop about 1/2 done looks like less than 100lbs will finish this job.

Have a pow-con like RnR for more than 20 years. lately its been sputtering than quit. Pulled the cover and found a lazy leg on the main breaker (off and on switch). Went to the dealer and he said he couldn't get parts any more. Found a universal breaker and put it on, now it welds like new again. Also have a Miller 110/240 stick welder, light as 2 feathers welds good and so portable, hard to live with out either. Corp. Am. doesn't want things to last that long any more, now a days we are a throw away society, wonder when we might be next on the list.

We have a couple Powcons, and the parts are now available through Arcon (the Powcon brand went away but the folks that know how to do this .... started up Arcon). Same heavy duty construct from what I can see. Really wanted one but wasn't calibrated for doing the FCAW process on CV constant wire speed settings.

Some of the differences of inverter welders include SCRs or IGBTs. Which sounds fancy but there are some differences in their switching capabilities.

Having said this: we will keep these Powcons (SCR) as long as we can, they are great for nice stick or solid wire GMAW welds - and on lesser quantity of available power.

Not sure what to do with my Lincoln diesel SAM 400 now that we have the under warranty Invertec. We tested (fully instrumented the machines for voltage and current) a few new inverter's using a strict setup for using FCAW structural steel wire with impact properties and selected those which had the correct calibration for the mfg's wire specs and selected red over blue due to the logistics / dealer. Plus we have always liked their products and have a good area rep.

And yes: Will still keep our 'original' buzz box with rectifier for AC/DC stick welder as well as the shop transformer stick and Tig unit.

And yes, I will weep when the repair bill for the new inverter comes to pass which I hope never will. If we run on a generator you can bet we will check all aspects of the power.

I think the inverter with a suitcase wire feeder is a better choice for us than a dedicated shop MIG unit.

If you can find a Powcon, certainly consider it. They are often on ebay or craigslist. Pay attention as some wont do wire and some are 480 only (dont ask how I learned this but if you go to the college you can find one there that was donated).

The pulse unit we haven't checked into yet - but thanks for the comments.

Oh yes.... and our compact 120/240 Thermal arc unit gets used all the time for all kind of odd repair work, especially when ladders involved: but dont be fooled this machine can weld you an AWS cert.

cowman, I'd seen a systematics machine before but never welded with one, actually didn't know they were made anymore, there are no service places around me that I know of for them but I'll check into them just the same. Can I ask why you won't own a welder once the warranty is off? I also noticed the noise thing in pulse mode, wasn't really excited about the pulse at all, you have to be perfectly flat surface to weld in that mode, have almost straight argon from what I was told and got the whole sales pitch you got when you bought yours. So what's your next welder once your 350 is off warranty, another one identical to it or something different?

Oceanbob, never heard of the Arcon welders before, never seen one around here either after powcon was bought out, but I'll check into them to see what they offer, like I'd said before powcon was a heck of welder, had wished I'd bought one many times over the years.

As for the inverter with a suitcase, what model and size of inverter are you thinking, I've run several besides my bobcat and 8vs and they do have their place, really handy in fact. I ran a larger lincoln transformer welder with a feeder on it and the tank was fastened to the wall, a really handy unit but limited to a short distance to welder at least the one I used anyhow, we ran the feeder from a overhead hoist and it was great, I've been given the sales pitch on that setup too, still haven't ruled it out for the shop setting.

Randy I will probably replace the 350p with a shop mate 300 DX as it has multi process Capabilities and the same or greater output. I was torn between the 2 when I bought the 350p the deciding factor was pulse mode and a 4 roller drive. But now that I have decided that pulse is a waste of money and my 12Vs suitcase with 2 roller drive feeds just as well as a 4 roller I would rather have the ability to stick, tig and mig with the same machine. The only stick welders I have are my bobcat 250 and a old Lincoln sae 400 they work great but stringing leads in the shop for a 2 minute stud removal job or a little cast iron welding job is a pain in the rear. I could also buy another wire feeder for it and not have to take 10 minutes to switch between 70s6 wire and 71m outer shield just have 2 guns with 2 feeders set up all the time. As for the warranty I may keep it around but a board or major repair can cost $1200 or more, my salesman will trade for less than $1500 maybe that is stupid but a new welder vs uncle sam taking my $ I would rather look at a shiny new welder. Who knows maybe I will just buy another one and keep this one, I just have some space issues in my shop 50' x 80' with 3 people working in there gets crowded. The systematics has a 350 amp machine with a remote wire feed that gives you the ability to carry it around like a suitcase and leave the power source in the corner. I have a salesman trying to sell me one all the time they are a good machine but I just like the miller.

We had our hands on the Arcon demo unit from the area rep twice (once at the welding school and then one other time) and then we tried one out in our shop for a good long day with some other machines when we did that volt ampere curve check business. I really felt like it was well made similarly in construct to the powcon, torroidal transformer etc. A lot of attention to the connections was seen inside. You can look them up on the web quite readily and call them to learn where your rep is located. Yes they do have the parts for the Powcons. They are great folks.
Please note: We were stymied with the Arcon with our odd request to run the structural steel FCAW: the mfgs specs on this are quite clear, for example the wire feeder cant be run on CC constant current (also known as VV variable voltage) to allow the suitcase to compensate the wire speed to maintain the voltage - this now is apparently a no no from the Inspector (CWI)s. When these wires first came out, there weren't as many inverter machines around but the technology has put the red and blue in a different league when it comes to this stuff. If we have to fab up a steel wide flange frame for a door on a building or a shear wall tie, we need to be able to run this wire and get 'signed off'. Otherwise we would probably just have an Arcon or vintage Powcon to take care of the stick welding. I did in fact plead with them if they would consider a optional volt amp setting for us FCAW structural steel suitcase folks and they said they were aware of the issue but it would be a some ways off.

The suitcase's we have is the LN25: we have the original version and it is plain with no gas kit and is set up to run the 1/16" FCAW wire, and a newer LN25 pro with the gas flow solenoid for the inner shield with cover gas wires people call dual shield (although I guess dual shield is a trademark thing) - this suitcase is set up to do .035 and .045 cored wires with the appropriate shielding gas.

I forgot to mention we have a little 120vac MIG unit that is usually set up for 035 FCAW (no impacts). This is for jigs, truck ladder racks, etc. Can be used with solid wire with cover gas on short arc for sheet metal patches when doing body work or a ss wire with trimix for ss sheet metal tables (14 ga min thickness).

I am hoping the controllability and the programs with the 350a inverter power source will give the proper tuning to make these suitcase welds better than we have done before. So far the FCAW is easily right within the mfgs spec and the machine clearly makes the stickout distance less critical for the operator. There is one thing about a newer inverter that is kind of amazing: instead of turning a dial to what looks like about 35 or 40 on the 0 to 100 dial, then measuring the amps with the meter to see exactly where you are at while you weld, with the newer machines you set what you want and the machine will hold that within a very close range. And they have things like hot start and dig control and other settings to make your stick welds good and look good too....yes this can be accomplished with the buzz box or the engine dynamo or the older powcon, but it is like having a newer truck - both will get you there, true. But hows the ride? Sometimes just for kicks I will use the buzz box to keep my helpers wondering what is what, and there is no problem.

As to how I check the volt amp, I measure the amperage with a hall effect style clamp on meter which is good for AC or DC, voltage confirmed with independent meter, and wire speed with a stop watch and a tape measure. There is a wheel thing that measure the wire speed - the Inspector has that one.

I delayed on getting the newer inverter for one reason - the money cause I didn't want to buy a used one due to the repair cost fear. If you buy Powcon you have to buy a used one. As I write this, I think other than my original buzz box and the 120/240 thermal arc inverter, this very well may be my first new welder in this size range and I have 10 total machines if I include the plasma but not the one I gave to the school. Like women with shoes I guess, can't ever have enough welders.

But I guess to keep things simple yet have very good equipment one could have an inverter, a suitcase, and a slick TIG inverter and be in pretty good company. A generator for the jobsite power where there is none.

Yair . . . For an old(ish) bush mechanic/welder I find this thread fascinating. It would be interesting to be still in the game with all this new technology.

I wonder though how much better is the end result?

I guess the new machines make up somewhat for lack of operator skills. I know in the early days of wire-feed there were problems with lack of penetration . . . the weld looked fine but in fact was just laying on top.

I wonder how much has changed. A couple of years ago a friend of mine was welding on a beam at a power station shut down and a supervisor asked him to weld a drilled lug onto a piece of heavy wall pipe. Unthinking he did so and thought no more of it until a few days later he saw a lifting block hanging from the lug.

The lifting task was finished but he bought it up at a toolbox meeting that if he had been told the lug was for lifting he would have burnt it on with sticks . . . seems even tradesmen in the game still have a doubt.

Cheers.

with single phase power you're limited as to what you can run in larger wire sizes. Welding and mainly structural steel is the main business here, and we go through alot of this same stuff on a day to day basis. Single phase is your killer, if you just want a dedicated mig machine i would say the miller 212 is your best bet bang for buck.

If you want a multi process unit i would say a Miller XMT-304 CC/CV with an LN-25 voltage sensing feeder would be the ultimate in versatility. You could get miller 12vs feeder also that would be tethered to the machine and powered over a 14 pin connection where you can set the voltage right from the feeder without running back to the machine or dealing with the the control cable ground for the over the arc power.

While all of my portable diesel drive welders are Lincoln i haven't had the best of luck with ANY Of their shop equipment, and i WILL NEVER buy an invertec welder from them again.

When arc products was still in san diego I loved every single one of my powcons but having to ship them across the country to get worked on when they needed something really sucked the awesome out of owning them.

having demo'ed all the newest fanciest pulse machines on the planet theres only three reasons to bother with them, one the STT/RMD settings are AMAZING for open root pipe, you simply cannot beat the ease of bedding in an open root with these processes. Second being metal cored wires being run out of position in a production setting. Third is aluminum pulse welding for heavy aluminum fabrications out of position. ANYTHING else its pretty much pointless to have pulse and just a waste of $.

Dualie, the sales people at one store have been working on selling me an invertec lincoln, a 350 something that runs on single phase power, I'd have to dig out the literature again to get the exact model, but I believe its the only one that does run on single phase or three phase power, what was it that gave you your opinion on them, I'm open to hearing anything both good and bad. I haven't run it yet, have been sick and not gotten back to do that, they said they'd set it up and let me weld with one though.

I've talked to so many people about welders but yesterday I ran across someone who told me this, and was wondering if anyone had ever heard this, I never had. He told me to go find a couple old DC stick welders and hook them together and air arc off single phase power with two machines instead of one, I'd have two cheap welders hooked up to two separate plugs and not exceed my shops amp load draw and do far better air arc gouging than any single phase new DC unit out there today ever could dream of doing. First off would this work, second has anyone done it before?

Thanks to cowman for the next bit of info, he told me about the systematics welders, which until he mentioned them, I'd never heard of before, didn't think any where around me at all, turns out I was wrong on many issues, first being that all new mig welder made today have a computer on them or chip boards or something computer related, systematics has none of this on them, they are just an old fashioned standard tap transformer mig welder, the larger units they make also have the highest duty cycle in the industry and also about the highest amps on single phase power in the industry 300 or more amps at 100 percent duty cycle and after a dozen or so phone calls, there's far more in my area than I ever knew existed, a few of the implement dealers, larger farmers, fab shops out of my trade area and some specialty shops run them, mainly due to nothing being computerized and having so high of duty cycle, a few ran them because they had separate feeders for them and could carry the feeder up onto or into machines to weld. I actually welded with one yesterday, a really nice simple welder like what I'm used to welding with and have welded with for decades, I want to weld with a few more machines and talk to a few more people that have had them for years, but I"m thinking right now, I'm leaning pretty hard towards a new systemics welder mig only machine.

I've never run or looked at the miller shopmate 300 cowman mentioned, none of the sales people have ever mentioned that machine, so I'm curious as to why not, they've mentioned everything else, I looked in the miller bible and by the specs its a nice machine and fit the criteria I had, so now I'm going to go annoy some more sales people and weld with a few more welders, if nothing else to at least say I did it and eliminate doubts later on and can say been there done that. At this point I may as well, I've run most of the rest, just not the lincoln invertec or miller shopmate 300.

Arcon is getting back to me but told me, there is no sales, support or service anywhere near me, they have a void in the midwest and especially in my state for any form of anything, which didn't really surprise me, but I at least asked, when I asked about a demo, the other end of the phone got really quiet, he told me he'd get back to me on that.

Hi Randy, I've just browsed across the thread, so here's my 2c

IMHO, don't touch anything without genuine after sales service and parts. Your major brands like Lincoln, Miller etc should be ok. Be aware that even the majors are manufacturing in China, so you have (in Australia anyway) two tiers of machinery, ie: professional and handyman. The handyman stuff is ok if you're buying on price not quality. Pretty much everything has PCB's in them now.
If you can, contact the local service agents for opinions.

Inverters and transformer type machines. I've hung off the end of transformer machines for most of my adult life. After leaving the contract game and getting into sales/service, I was introduced to the inverter type machines and have never looked back.

For quality of weld, ease of use and efficiency of power, the inverters are the way to go. A synergic MIG or Pulse MIG makes it even easier. If you're welding aluminium, the Pulse MIG is the best choice. It's even good for flux-cored wires and great on hardfacing.
The inverter uses power more efficiently than a copper winding, so you'll get a higher output based on the input power.
Personally, the inverters are my choice. Modern gear will produce the best welds hands down (taking operator into consideration)
I talk to many middle aged farmers (sometime users) that "don't want any of that digital crap" while browsing their Iphone to show me comparable transformer machines. I mean, you didn't use a typewriter to start the thread eh!

If you want to run off a generator, not worried about how much power you're chewing, or don't want to learn how to use a modern machine; the transformer could be the way to go for you. I still keep a small transformer type Lincoln 170 MIG for mobile, flux core welding. You can run inverters on generators, although you must have clean output and oversized generators for that. (eg: 6500watts to safely run a 140a stick inverter)
As far as the older transformer type machines go, I see them come in to the shop weekly. Anything over 10 yrs old and the manufacturers are de-stocking parts. We have refurbished MIG's for sale at virtually cost price and have trouble moving them.

One of the multi process stick/DC TIG/MIG would be my choice.

my luck with the invertecs has been CRAP! Heck i went back to the Lincoln electric factory for a factory course on FCAW wires in the early 00's and they couldn't keep them running in the building that they built them in! we let the magic smoke out of 3 of them in one week! I'm NOT A FAN.

The miller XMT's are auto line sensing and will work on anything from 220 single phase to 480 3phase without changing anything. it will sense the line voltage and make automatic corrections.

IF you are going to air arc i HIGHLY recommend not doing it with inverters, you can most definitely hook two CC/DC machines together to air arc. local company here had two 1000 amp Lincolns hooked in tandem and would use 5/8 x 1" flat carbons to gouge with. they would really blow some metal around with them.

Have appropriately sized leads and have them wired on separate appropriately sized breakers and you could save some bucks.

I have also been hearing good things about the thermal arc fabricator 211 on single phase power that is an all in one mig tig and stick