3 Phase Mig

[mud90mike]

Hi All,

We have been hitting the capacity with our 230 Portamig and I need to start looking for something bigger, We will need to use it for up to 30mm Plate but also a machine that could be used for 3/4mm would be useful. What do people recommend for a good workshop machine that will be reliable and good quality

Thanks for your help!

 

[BrokenBiker]

get a 3 phase portamig? they do 285, 335 and 405 amp 3 phase machines

 

[Tom Orrow L]

Flippin' heck what you welding that's 30MM? Reckon you'll need a good 500-600A for good penetration on that.

 

[normspanners]

Flippin' heck what you welding that's 30MM? Reckon you'll need a good 500-600A for good penetration on that.

That is roughly what I used to use for 30 mm fillets power was there but big problem was wire feed even with 1.6 flat out, I also used 6mm bright steel as a filler at the bottom of the fillet to help stop blowing through and used another piece and fed it by hand ala tig--------- then comes the helmet and glove problem -----.

 

[Tom Orrow L]

That is roughly what I used to use for 30 mm fillets power was there but big problem was wire feed even with 1.6 flat out, I also used 6mm bright steel as a filler at the bottom of the fillet to help stop blowing through and used another piece and fed it by hand ala tig--------- then comes the helmet and glove problem -----.

Sounds awfully difficult, looks like something that Jim would be able to sort with one of the big EWM's.

 

[Welderpaul]

Was talking about this the other day. There's a misconception that if you are welding thick plate (say the 30mm), that you need millions of amps/volts to weld it with. You're never going to weld it in one pass - maybe for a single sided bevel butt, might need 10 runs or so based on 8mm fillets which is the biggest I can neatly lay in one pass without starting to get slumping/undercut.

If the welding current is too high then the beads are just a wobbly uncontrollable mess. In reality your only going to weld it at similar settings as you would to do a single pass in say 8mm or 10mm plate. Your only looking to penetrate into the parent metal and/or previous beads so why do you need a huge welding current?

Machine duty cycle comes more into play here - a, say, 500 amp machine, whilst you would never be anywhere near top end, will happily run all day, whereas a, say, 300 amp machine will still perform the same but will be spending more time cooling down than welding.

I guess if your welding plate of that size it's for making money rather than a hobby. Depends how much you want to spend, what sort of reliability you need (Is it going to cost you heavily if a job doesn't get finished on time if the set breaks down) and long term requirements.
There's loads of 3 phase machines on ebay or machine auctions that go for peanuts. You take your chance on what level of mistreatment they have had though. Or buy new. Esab, Lorch, Lincoln, EWM, there's loads. If your waving a few quid about for a new one, there will be a welding supplier that will be happy to help you spend it plus you will get the back up if there is a problem. (He will be biased towards whichever machine dealer/s he is in bed with but a reputable welding supplier will make sure you get the right machine for the job)

Welding suppliers often have a hire fleet that they sell off once the sets start to look a bit tatty, or reach a certain age. These can be quite good value as they have usually been serviced frequently and had money spent on them to keep them in good condition and preserve the welding suppliers reputation. Sometimes get a limited warranty with them too.

 

[mud90mike]

Hi All, Its mainly plates and beams for a job at Heathrow, everything is hugely overspec'd to the point of being daft. we made a 152 x 152 x 30 beams with 25mm plates to form a goal post to hold 100 kg. but works work! we just do what the drawings says.

Its is for work rather than a hobby so it needs to be reliable, I had a look at the portamig 400 as we are very happy with the smaller one, but in some ways I would rather have a bigger one that will do any future job rather than risk having to upgrade again. Whilst I don't want to throw limitless money at one I would rather spend once and spend right. I would rather buy new and get a decent warrantee / support, I have been told Murex are one of the better brands to aim for just after other peoples opinions / ideas.

many thanks

Mike

 

[Welderpaul]

Go for Lorch

(I'm heavily biased too)

 

[Tom Orrow L]

Was talking about this the other day. There's a misconception that if you are welding thick plate (say the 30mm), that you need millions of amps/volts to weld it with. You're never going to weld it in one pass - maybe for a single sided bevel butt, might need 10 runs or so based on 8mm fillets which is the biggest I can neatly lay in one pass without starting to get slumping/undercut.

If the welding current is too high then the beads are just a wobbly uncontrollable mess. In reality your only going to weld it at similar settings as you would to do a single pass in say 8mm or 10mm plate. Your only looking to penetrate into the parent metal and/or previous beads so why do you need a huge welding current?

I remember a post on here now too long back about a guy welding 30MM plate with a double sided bevel & did a fair few passes on it to get it welded right. Don't remember what size machine he was using though.

Hi All, Its mainly plates and beams for a job at Heathrow, everything is hugely overspec'd to the point of being daft. we made a 152 x 152 x 30 beams with 25mm plates to form a goal post to hold 100 kg. but works work! we just do what the drawings says.

Its is for work rather than a hobby so it needs to be reliable, I had a look at the portamig 400 as we are very happy with the smaller one, but in some ways I would rather have a bigger one that will do any future job rather than risk having to upgrade again. Whilst I don't want to throw limitless money at one I would rather spend once and spend right. I would rather buy new and get a decent warrantee / support, I have been told Murex are one of the better brands to aim for just after other peoples opinions / ideas.

many thanks

Mike

Suppose it has to be at Heathrow, imagine if something went wrong there
Murex are very, very good machines but you'll struggle to find brand new nowadays. You might want to ask Matt or Jim Davey about either EWM, Lorch or ask about various suppliers about what they recommend. You'll find once you tell them you want a big MIG they'll be awfully helpful

 

[BrokenBiker]

@matt1978 maybe able to help with info?

 

[BrokenBiker]

or @Jim Davey or @weldequip

 

[Jim Davey]

I'm always awfully helpful

 

[Jim Davey]

Was talking about this the other day. There's a misconception that if you are welding thick plate (say the 30mm), that you need millions of amps/volts to weld it with. You're never going to weld it in one pass - maybe for a single sided bevel butt, might need 10 runs or so based on 8mm fillets which is the biggest I can neatly lay in one pass without starting to get slumping/undercut.

If the welding current is too high then the beads are just a wobbly uncontrollable mess. In reality your only going to weld it at similar settings as you would to do a single pass in say 8mm or 10mm plate. Your only looking to penetrate into the parent metal and/or previous beads so why do you need a huge welding current?

Machine duty cycle comes more into play here - a, say, 500 amp machine, whilst you would never be anywhere near top end, will happily run all day, whereas a, say, 300 amp machine will still perform the same but will be spending more time cooling down than welding.

I guess if your welding plate of that size it's for making money rather than a hobby. Depends how much you want to spend, what sort of reliability you need (Is it going to cost you heavily if a job doesn't get finished on time if the set breaks down) and long term requirements.
There's loads of 3 phase machines on ebay or machine auctions that go for peanuts. You take your chance on what level of mistreatment they have had though. Or buy new. Esab, Lorch, Lincoln, EWM, there's loads. If your waving a few quid about for a new one, there will be a welding supplier that will be happy to help you spend it plus you will get the back up if there is a problem. (He will be biased towards whichever machine dealer/s he is in bed with but a reputable welding supplier will make sure you get the right machine for the job)

Welding suppliers often have a hire fleet that they sell off once the sets start to look a bit tatty, or reach a certain age. These can be quite good value as they have usually been serviced frequently and had money spent on them to keep them in good condition and preserve the welding suppliers reputation. Sometimes get a limited warranty with them too.

You would be able to get that done with much fewer passes using force arc (EWM) or the speedpulse (Lorch) process, or maybe make the swap to FCW if the lack of deposition rate is slowing things down and costing you money.

 

[normspanners]

You're never going to weld it in one pass - maybe for a single sided bevel butt, might need 10 runs or so based on 8mm fillets

The item I was making had more than 110ft of at least 25mm fillet welds on the one unit the base was 30mm , so times that by 10 passes would equal 1100ft of welding !! the first prototype took nearly 5 days, I had a holiday booked so had to try and make the second one in 2 days= 48hrs, that including the grinding etc the unit was an ingot so couldnt leave plain weld on inside had to be ground off, I had to find away to cut down on welding time my old machine ran at 500/600amps continuous-- so used it. I had afork lift with arotory head so it was all down hand, The heat was something else though, and hard to stand for 35/40hrs solid welding.

 

[Richard.]

SAW. if money's no object and its repeatable design.

 

[Welderpaul]

You would be able to get that done with much fewer passes using force arc (EWM) or the speedpulse (Lorch) process, or maybe make the swap to FCW if the lack of deposition rate is slowing things down and costing you money.

Yeah I know, we have Speedpulse on all our machines...Portamigs don't though. I used a transformer MIG the other week, after so long using these it was like going back to the dark ages!

 

[weldequip]

Now don't come on ere crying when you eventually get a four figure repair bill for your fancy pants gizmo's...very much 21st century they are!

 

[Welderpaul]

Now don't come on ere crying when you eventually get a four figure repair bill for your fancy pants gizmo's...very much 21st century they are!

Ha ha, shove it outside for the local travelling scrap collectors and buy another. They've already paid for themselves after a while. One thing I've learnt in business is not to faff about trying to fix terminally knackered kit.
Hope you're keeping well Steve.

 

[TechnicAl]

Was talking about this the other day. There's a misconception that if you are welding thick plate (say the 30mm), that you need millions of amps/volts to weld it with. You're never going to weld it in one pass - maybe for a single sided bevel butt, might need 10 runs or so based on 8mm fillets which is the biggest I can neatly lay in one pass without starting to get slumping/undercut.

If the welding current is too high then the beads are just a wobbly uncontrollable mess. In reality your only going to weld it at similar settings as you would to do a single pass in say 8mm or 10mm plate. Your only looking to penetrate into the parent metal and/or previous beads so why do you need a huge welding current?

Machine duty cycle comes more into play here - a, say, 500 amp machine, whilst you would never be anywhere near top end, will happily run all day, whereas a, say, 300 amp machine will still perform the same but will be spending more time cooling down than welding.

I guess if your welding plate of that size it's for making money rather than a hobby. Depends how much you want to spend, what sort of reliability you need (Is it going to cost you heavily if a job doesn't get finished on time if the set breaks down) and long term requirements.
There's loads of 3 phase machines on ebay or machine auctions that go for peanuts. You take your chance on what level of mistreatment they have had though. Or buy new. Esab, Lorch, Lincoln, EWM, there's loads. If your waving a few quid about for a new one, there will be a welding supplier that will be happy to help you spend it plus you will get the back up if there is a problem. (He will be biased towards whichever machine dealer/s he is in bed with but a reputable welding supplier will make sure you get the right machine for the job)

Welding suppliers often have a hire fleet that they sell off once the sets start to look a bit tatty, or reach a certain age. These can be quite good value as they have usually been serviced frequently and had money spent on them to keep them in good condition and preserve the welding suppliers reputation. Sometimes get a limited warranty with them too.

Add to that..........using a 1.6mm wire may not improve your deposition rate. 1.6mm is actually nearly 80% bigger than 1.2mm. So if you can run your 1.2mm at 300 amps would will need to run a 1.6 at 540 amps to get the same deposition rate. What you will get is a bigger weld. 80% more in fact.

But as Paul says 8mm is about the max leg length for a fillet in one pass before gravity takes over and you get a flatter wider nugget