ARC Outs?

[heather dunn]

So I just want to start off by saying that I am not a welder, I have tried mig hand weld and I sucked so I stopped. However I work in manufacturing quality and deal with both Robotic MIG and TIG welding, I have a good grasp on what's a good weld and what is not and have performed weld macros for years. I think I understand the basics of the process I just don't know crap about certain terms and issues and doing research on the internet well lots of misinformation. So my main questions is this. On a MIG welder the operator complains of "arc outs", what actually causes this to occur and what is the welder actually doing?
I just want to understand more about welding.

 

[Country Joe]

Hi there, Heather - and welcome to the Forum!

I’m not sure what you mean by “arc-outs”, but I’m going to guess that you mean the arc isn’t as stable as expected, and sometimes seems to stutter, or even go out for a split second.

If so, I would expect it to be a wire feed problem. A bit like the problem that SIP welders were (or are?) known for.

If the wire doesn’t come out of the front of the torch at a consistent rate, it can burn back slightly, but far enough to lose electrical contact with the work-piece for a split second, before it touches on the work-piece again,.

It’s usually a momentary thing, but after a (very short) while it’ll become quite annoying, especially if it’s happening regularly enough to make it sound like a machine gun most of the time.

This, in turn, seems to make it spit more, and will effect the weld - as a continuous, regular crackling sound is what you’re after, as opposed to a staccato, irregular sound.

If so, it’s most likely caused by the mig wire slipping, due to the drive rollers not being under enough tension to grip the wire properly. The same would also happen if the tension was correct, but the drive rollers had any grease or dirt on them.

Another cause could be that the spool of wire is too tightly held, and cannot turn freely enough to allow the drive motor, or the rollers from being able to push the wire through, as there is too much of a dragging effect on the wire for it to feed properly.

A bad earth could also give the symptoms you describe - it needs to be a good tight connection on a clean and shiny part of the workpiece.

I’m sure other folk will be along with other reasons before too long - as this is probably not a definitive answer!

All the Best,
CJ

 

[heather dunn]

Thank you! It does help me understand what might be going on.

 

[chris y]

Are you referring to an automated production process where an arc out means the process stops and the now defective part reworked manually or do you mean manual welding?

I've only come across the term on automated production processes making safety critical parts, when the machine would detect an arc out it would stop because of the potential of a weld defect.

Any break in current flow would be seen as arc out, could be many causes, most often wire feed but could be other things like contamination on parts or bad robot programming moving the torch away from the work while it changes angle.

I'm not an expert though.

 

[Robotstar5]

I've only come across the term on automated production processes making safety critical parts, when the machine would detect an arc out it would stop because of the potential of a weld defect.

I've always known that as an "arc fail" normally monitored by "arc established" sensor.

 

[Sparkey]

I've always known that as an "arc fail" normally monitored by "arc established" sensor.

Yes same here, arc fail will even occur when something simple like the wire sticking to the part happens... Happens on all mig robots i guess quite annoying but don't think there's much to do about it? Please tell us more about the setup this operator is using....robot? Manual welding? What? How?
Sparkey