Annoying problem with MIG

[SiPMerlin150]

Okay guys, I've done a lot of welding this afternoon and yesterday to a older Mazda caravan, 20 inch patch on the sill, 12 inch patch on the inner sill and a 30 inch plate on the crossmember that a leaky radiator helped rust out, and a 4 inc plate patch over the rear of the back silencer... A lot of welding!

The garage has a brand new lincoln '191c' powertec mig and this was the first time I used it, previously we had an old old (10 years) lincoln compact 185.

I welded beautifully with the old one, same wire, same gas etc.

This new welder has arc blow issues, or it seems, it puts down very cold looking welds down even though its set 60% higher than it normally would be for 1.6mm steel.. The arc transfers from the usual sizzling sound to a quiet hiss a lot of the time.

I've tried to play with the wire speed is set to the point where its close to stubbing into the work piece to overcome the odd arc characteristics, and it hasn't helped, neither has reducing the wire speed to the point where it balls up to the tip.. One more thing is that unless the shroud is physically touching flush to the work piece, the weld seems to spatter and not be shielded properly.

The shielding gas has been ran anywhere between 15-20 lpm argoshield light, (new bottle got today, made no difference) the gas diffuser orifices are clear, the tip and shroud are kept spatter free, The steel is clean, and grinded shiny, aswell as the area surrounding the weld. The ground clamp is within 8 inches of the area to be welded too.

I'm stumped, its making me look like I've used a pigeon to weld with and its very embarassing! I can pick up any MIG and weld very clean straight beads once I've set it up to my likings.

At the moment, my cheapo powercraft MIG makes better looking welds than this £900+ lincoln....


Anything that you could think of that would cause a problem? I'm seriously stumped.

 

[Justme]

Check the return cable.

Last time mine went like that the clamp screws had loosened & the cable was nearly falling out.

 

[mike 109444]

Does it have capability to "gasless" weld and if so is the + and - ( clamp and gun) set correctly?

 

[SiPMerlin150]

Check the return cable.

Last time mine went like that the clamp screws had loosened & the cable was nearly falling out.

Will do that, All seemed shiny and new so I didn't expect it to be loose, I'll have a look tommorow, I don't think theres any welding booked in tommorow, that can change depending if an old rusty car rolls in on the MOT ramp..

I did my best with the welder and completed the job. Ended up a fairly 'decent' job for a usual MOT garage repair

This was one of the repairs...

 

[SiPMerlin150]

Does it have capability to "gasless" weld and if so is the + and - ( clamp and gun) set correctly?

Yes, had a peek in the box at how much wire was remaining and saw the polarity changing connections, both the cables were the same color.... I need a better look at where these wire go,

 

[SiPMerlin150]

Had a look inside the box today when another one of the lads complained about the lack of performance of the MIG, I couldn't clearly see where those wires led to as they both disappeared behind the wire feed roller assembly. Switched the leads over inside the welder and he said the welder was behaving 'a bit better'. I'll need to give it another go and see if anything else is amiss..

 

[oilcooled :)]

Put the torch off the old machine on to the new machine and this will help rule out if you have trouble with the torch. Bad wire feed on Lincolns keep torch lead straight ish

 

[SiPMerlin150]

Put the torch off the old machine on to the new machine and this will help rule out if you have trouble with the torch. Bad wire feed on Lincolns keep torch lead straight ish

I was hoping for them to throw out that old MIG..and then it will land straight in the back of my car instead of the landfill! Of course, I'd ask them first rather than just take it..

I wouldn't of thought those Lincolns would have problems with wire feeds..

 

[oilcooled :)]

The ones i used werent hectic great

 

[SiPMerlin150]

I was hoping that a MIG for just under a grand would of done the trick, this thing is brand new, They'd be better off with a portamig, but its not my business at the end of the day..

I'm ashamed of the quality of the welds I did on that car, they look like bird poo but surprisingly they have took the brunt of force (Jacking point on a caravan)

So I'm happy that the welds are up to their intended purpose.


I mean, look at the state of this...

This was the jacking point, I cut out the rotten metal, plated the innersill , and plug welded it to the outer sill lip, then replated with a seam over the back part of the lip to reinforce the sandwitch of new metal.

Looks like hell and all, but it holds..

 

[Jee]

What transfer mode are you on? It sounds like low level pulse which sounds like humming rather than the sizzling sound you mention.

 

[matt1978]

Did you try it on the bench with clean material? To at least rule out whether there was some sort if problem either magnetic or contamination on the car??

If the wires had been reversed and it was welding DCEN then when you changed it back round it should of been the difference between night and day, not "a bit better" like your mate said so I doubt it was that.

If you can hear some sort of low level frequency resonating from the machine it usually means that the Transformer is damaged. But although not impossible, certainly not likely on brand new machine.

My advice would be to get back to basics and see if its possible to run some beads in Dip transfer on nice clean material at the bench, if its still as bad, change the wire, gas and torch off a rig that you know works, if its still the same then it's obviously a problem with the unit. Get the boss to call the company where they bought it from and at least give them/Lincoln the chance to rectify it or even replace the machine.

I'm sure Lincoln give 5 yrs warranty on the Transformer and the rest 3 yrs so whatever it is should be covered.

I work for a manufacturer now but I did start off on the tools, so I see it both ways, but sometimes it's too easy to blame the machine, when there are other equally as vital parts in the chain such as torch and consumables or even electrical supply that can be the cause.

Even if it is the machine which it very well may be, it's a man made item so sometimes things just don't work. As frustrating as it is it shouldn't give you a bad impression of that particular brand as I know in general they are very good. If it is the unit give them chance to resolve it and if your still not happy then make a impression then.

Good luck anyway, I know how cack it can be when you know what you can achieve work wise but are held back by shoddy equipment

 

[SiPMerlin150]

What transfer mode are you on? It sounds like low level pulse which sounds like humming rather than the sizzling sound you mention.

Its supposed to be dipped transfer as the wire speed and power was set on the machine quite low, (2 out of 8 on volts) and 3-3.5 on the wire speed.

It sizzles for a brief moment, then it goes very quiet to a quiet hissing like steam. At first I though my angle was wrong, but that made no difference, so I tried holding the shroud to the work closer, even to the point of resting the shroud on the work piece.

I'm not too sure if this welder is capable of pulse transfer, it has a spot welding timer, '2 or 4 stroke' capability and a burn back control.

 

[SiPMerlin150]

Matt1978, I've not tried the machine myself after he changed the polarity, so I cannot comment on whether or not how 'better' it is welding. I'll clean up some small pieces of plate and attempt a few beads on them and see how it behaves.

I know Lincoln stuff is top quality kit, so I was a little surprised. I kept the ground clamp as close as possible to the area of welding (6-9 inches) to reduce the bad earthing problem you can get.

This week I'll try to get to the welder and have another play around with it.

 

[backpurge]

Its supposed to be dipped transfer as the wire speed and power was set on the machine quite low, (2 out of 8 on volts) and 3-3.5 on the wire speed.

It sizzles for a brief moment, then it goes very quiet to a quiet hissing like steam. At first I though my angle was wrong, but that made no difference, so I tried holding the shroud to the work closer, even to the point of resting the shroud on the work piece.

I'm not too sure if this welder is capable of pulse transfer, it has a spot welding timer, '2 or 4 stroke' capability and a burn back control.

That machine does not have a pulsed transfer mode

 

[SiPMerlin150]

That machine does not have a pulsed transfer mode

Thats what I thought. Theres no digital display of anykind of showing you volts, amps and wire speed, and frequency either.

 

[Jee]

Its supposed to be dipped transfer as the wire speed and power was set on the machine quite low, (2 out of 8 on volts) and 3-3.5 on the wire speed.

It sizzles for a brief moment, then it goes very quiet to a quiet hissing like steam. At first I though my angle was wrong, but that made no difference, so I tried holding the shroud to the work closer, even to the point of resting the shroud on the work piece.

I'm not too sure if this welder is capable of pulse transfer, it has a spot welding timer, '2 or 4 stroke' capability and a burn back control.

If it sizzles for a moment that sounds like hot start kicking in.

I don't know the machine just trying to help.

 

[matt1978]

Hi Jee it won't have a hot start because its a Transformer. You can't have Hot starts or Crater fill on Transformers.

 

[Drains]

Unhitch the wire feed roller(s) and check the wire is running freely through the liner/torch- grab the wire at the tip and haul gently. It sounds like you might have a feed issue. Worth eliminating the possibility anyway.

 

[SiPMerlin150]

I'll check the wire feed tommorow, I've just remembered that they got the new MIG when I was off for a week, and it had came with 1.0mm wire, and they had swapped it out for 0.6mm wire, so I'm wondering if they haven't swapped the rollers around?

hmmmm... At the end of the day, they are mechanics and other than swapping the wire spools and using the welders, they wouldn't really know much about welding equipment and its needs.. For example, They be wondering what I'm talking about when I mention how I use a gasless MIG wire at home..