Three phase mig or single phase

[Marshall92]

Hi I have recently started renting a workshop unit not for welding primarily but i do need to weld some hefty things now and again. Would I notice a big difference using a 3 phase mig compared to a single phase? I do have 3 phase in my workshop. Thanks in advance.

 

[R J]

in my experience yes , 3 phase much more heavy duty so you would have less problems welder cutting out overheating etc

 

[AJR75]

Go three phase- used machines are plentiful and affordable in comparison to single phase ones.

My first workshop was on single phase and there was barely enough juice in the line to get 1mm wire into spray transfer. Also with other houses on the same phase of supply as me, their lights used to dim when welding in the evening, luckily back then they were very tolerant neighbours.

I can't comment on the performance of the newer inverter based machines though and they may be a different kettle of onions.

 

[Marshall92]

Thanks for that yes I have seen a migatronic flex 400 with seperate wire feed but the cables from base unit to feed are only 2m can these be extended if I took it to a welding supplies? also can water coolers be retro fit as I would want the torch water cooled.

 

[AJR75]

Yes and yes is the answer. Mine is a separate like yours but in reality the machine get wheeled around the workshop rather than just the head unit. Always found the interconnecting cables far too cumbersome and annoying.

I have a a Kempii RA 450 bought from these guys:

https://www.specialistmachineparts.co.uk/ Contact Matt

He sourced and retro fitted the water coolers on several machines for me. There's no way given a choice that I would go back to an air cooled torch now.

 

[Marshall92]

Can you remember how much you paid for the water cooler fitted? Cheers

 

[AJR75]

I had three done in one hit (apparently it's a straightforward job to DIY) and from memory the cost was in the region of £450/ machine for the cooler, torch and fitting.

 

[Munkul]

Definitely 3 phase.

something 300 amps + from Kemppi, Miller, Lorch IMO, and personally I prefer inverters, even older ones.

You can retro fit any welder with a water cooler, it's just the torch swap really. But unless you're regularly welding heavy sections I don't think it's worth it.

I retro fitted both of our kemppi kempomat 4200's at work with coolers, and the lads using them really feel the difference... but they're doing medium to heavy fabrication every other day or so.

 

[Marshall92]

Which welder would you go for? Old inverter yes but which one? I can get a migatronic flex 400 for not a lot and I'm sure that is inverter based. Chap that uses it now uses it on structural stuff so it is calibrated but it is old ish.

 

[Munkul]

Migatronic inverters have a reputation for being expensive or very difficult to fix sometimes. Excellent transformer machines though. If it's cheap, then maybe worth a gamble

The most bombproof inverters are multiprocess machines designed for heavy fabrication in places like shipyards... well designed, lots around, and are relatively easy to get repaired, even at 20 years old these are great machines still. Plus, they have smoother DC stick welding than you'll find on anything else.

I'd be looking for either an Esab Warrior 400 cc/cv or a Miller XMT 304/350 cc/cv with a wire feeder, with my own money. In fact, i did... I have an XMT 304 with a 64 feeder, it's 23ish years old and welds every bit as nicely as the newest and best machines on the market. I'd reccomend an XMT to anyone. The newer ones have autoline, which you can feed anything into - 240v single phase up to 415v 3 phase and it will just work.
I know of at least two weld shops that would fix these machines no problem for me, their techs know them inside and out. You probably want to pay around £1000 for one in good nick with a 4 roll wire feeder.

Possibly a Lincoln, but I still have never used a Lincoln MIG that I actually liked! Other than the latest speedtec 405 which is overpriced and under-featured.

Kemppis are awesome too, in fact for general farm work I'd have a kempomat transformer over an inverter just for peace of mind - kemppi inverters are expensive to fix too.