stainless wire.

[qwakers]

I’ve never heard such a thing for stainless, although i am aware of the issue for alloy.

I don't think the wire is badly wound. I don’t think it’s a roller issue either, it’s definitely north of the rollers that is causing the issue.

I’m leaning more and more towards needing a Teflon liner, although it might be worth trying a bigger tip.

 

[DickyDoDah]

Depending on how long into a weld the bird nesting occurs you could try removing the tip and turning off the gas and just hold the trigger. If it still bird nests then the liner is a very likely cause. You can wind it back on the reel but make sure that it doesn't pick up dirt from the floor and don't forget to release the wire feed roller when winding back. If this is ok then it is snagging elsewhere. I'm sure it's already been said but the wire feel roller should be set as loose as possible, I set mine by loosening until it slips and then tightening back up just a bit. if you also have a roll tensioner that needs to be set so that the roll stops when the wire feed stops but does not cause too much drag. With stainless being so much harder than mild steel the wheel pressure is more critical. I do have to say that when I tried stainless on a Sealey MightyMig 150 I had no issues.

 

[DickyDoDah]

Another thought. I did have an issue on my Sealey with wire feed being inconsistent. The best I can explain it is that it was stuttering. I did all the usual checks and found nothing and then decided to strip the feeder mechanism. All plastic so I didn't hold out much hope. The gearbox looked fine but there was little to no grease so I just rebuilt it with new grease. The motor felt a bit rough so I connected it to a battery and it was definitely not running at a constant speed. I flooded it with electrical cleaner and hey presto it was smooth as silk I put it all back together and for the first time the speed control was linear and my welds were actually smooth again.
Whilst this doesn't sound like your issue it may be adding to it as the springy nature of SS with an inconsistent feed may be causing snagging.

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[Munkul]

have you tried new tips? I didn't see them mentioned anywhere.
Stainless does expand more than steel, but not as much as aluminium. I wouldn't have thought expansion would be the problem, but a worn or damaged tip would snag on the wire easily.

 

[DickyDoDah]

first question asked

 

[Munkul]

first question asked

so it was, I've lost the plot

 

[qwakers]

Depending on how long into a weld the bird nesting occurs you could try removing the tip and turning off the gas and just hold the trigger. If it still bird nests then the liner is a very likely cause. You can wind it back on the reel but make sure that it doesn't pick up dirt from the floor and don't forget to release the wire feed roller when winding back. If this is ok then it is snagging elsewhere. I'm sure it's already been said but the wire feel roller should be set as loose as possible, I set mine by loosening until it slips and then tightening back up just a bit. if you also have a roll tensioner that needs to be set so that the roll stops when the wire feed stops but does not cause too much drag. With stainless being so much harder than mild steel the wheel pressure is more critical. I do have to say that when I tried stainless on a Sealey MightyMig 150 I had no issues.

it either birds nests instantly after sparking up or lasts the full weld, maybe 2 or 3 welds, then birds nests instantly next time it arcs up. it will feed forever with the trigger pulled without trying to weld.

the wire feed on mild (and on stainless when it feels like playing ball) is smooth and consistent.

 

[Munkul]

it either birds nests instantly after sparking up or lasts the full weld, maybe 2 or 3 welds, then birds nests instantly next time it arcs up. it will feed forever with the trigger pulled without trying to weld.

the wire feed on mild (and on stainless when it feels like playing ball) is smooth and consistent.

Are you cutting the ball off the tip each time? What's your earth like? Does it ever "machine-gun" on starting? Can you feel it pushing the gun on contact?

It sounds like it could be a bad arc start rather than feed related, and 0.6mm is unforgiving at the best of times.

Some machines are just crap at arc starts, got rid of 2 MIGs that just couldn't start smoothly.

 

[fizzy]

I learn something new every day. Didn't realise you could weld stainless with a Mig? I assume you use pure argon?

 

[qwakers]

Are you cutting the ball off the tip each time? What's your earth like? Does it ever "machine-gun" on starting? Can you feel it pushing the gun on contact?

It sounds like it could be a bad arc start rather than feed related, and 0.6mm is unforgiving at the best of times.

Some machines are just crap at arc starts, got rid of 2 MIGs that just couldn't start smoothly.

yes i cut the ball off, earth is spot on, directly earthed to the part being welded, it never machine guns and i get no push back.

the welder occasionally gives a poor arc start but that is down to surface prep of crappy rusty steel, not the welders fault.

 

[Paul.]

I learn something new every day. Didn't realise you could weld stainless with a Mig? I assume you use pure argon?

For migging stainless properly you really need an argon / helium / co2 mix, Stainshield is the BOC version, sit down before you look at the price though,
Pure argon just splutters and makes the arc unstable, for the odd non critical job most just use their usual argon / co2 gas mix, it will give a grey oxidised appearance to the bead and produces spatter, but you can clean it up,

 

[hotponyshoes]

Argon with 2-3% c02 works ok and it's the same price as argon.
Use a correctly set-up pulse mig and you can almost eliminate splatter.

it either birds nests instantly after sparking up or lasts the full weld, maybe 2 or 3 welds, then birds nests instantly next time it arcs up. it will feed forever with the trigger pulled without trying to weld.

the wire feed on mild (and on stainless when it feels like playing ball) is smooth and consistent.

Try leaving the side door open and getting someone to watch while you run a few welds. Check the drum is not running on when you finish a weld etc.
You could set up a phone to video it if working alone and shout at it when you get a problem.

Presumably it's a .6 drive roller fitted (and it's the correct way around?)

 

[hotponyshoes]

Ps,
If you are just using the normal mig gas that would explain all the problems...

 

[qwakers]

Ps,
If you are just using the normal mig gas that would explain all the problems...

I'm using air products COOGAR gas (co2/oxygen/argon) as paul says up there^^^ it works fine for stainless as long as you don't care about looks. if I cared about aesthetics I would be tigging this. I also cant see any reason the wrong gas would cause feed issues....

its all academic now though. I struggled on far enough to get the job done.

the only thing mentioned in this thread that makes any sense is that I'm using the wrong liner. it makes sense as its like the ss wire is galling on the liner and jamming, or trying to weld itself for some other reason to the liner. a couple of times it jammed without birds nesting and taking the tip off (that came off no issues) and giving the wire a tug got it to free off and it felt like it was stuck to the liner... pulling it gained me 20 or so mm of wire out of the nozzle without moving it in the feed rollers...

I was unaware you needed a Teflon liner for SS MiG, however that is what I will try next time I want to MiG stainless, which is rare enough that ill probably forget all about this until it jams on me