- Thread starter D5meister
- Start date
Appyasme1
Member
- Messages
- 1,385
- Location
- Lancashire
Try changing yourcollet
Richard.
Member
- Messages
- 18,344
- Location
- Cambridgeshire
Perfectly normal
It’s where the gas isn’t providing protection against oxides when the tungsten cools.
The silver part of your tungsten from that line onwards is protruding out of your lens and getting High on sweet argon with your post flow. The heat tinted part gets hot and no protection when it cools and below that it doesn’t get hot enough to change colour.
Don’t worry about it.
Richard.
Member
- Messages
- 18,344
- Location
- Cambridgeshire
Lol we will have to agree to disagree here mate. It’s heat tint (surface oxides) and where there is no inert gas protection behind the lens when the tungsten cools rapidly. this is very common. It’s also completely harmless contained behind the collet. It also rubs off in seconds with a bit of scotch bright. I wouldn’t be cutting an inch of tungsten off every time I saw that. I’d have no flipping tungstens left.
Brad93
Member
- Messages
- 19,001
- Location
- Essex, United Kingdom
Yep I think we will mate.
There’s gas behind the Lens. Gas goes right up into the back cap.
I also wouldn’t touch a tungsten with scotchbrite either. You’re gonna put all scratches in to it and some types of scotchbrite are impregnated with a lubricant soap.
I see people time and time again get that stuttering start and black soot on AC.
They’re wire brushing and cleaning their part, checking their gas, when all it is, is the last time they touched down they just reground their tungsten.
On AC the tungsten gets much hotter than DC as we all know. The current is also going in two directions.
From the torch to the workpiece in the electrode negative EN cycle and from workpiece to torch in EP cycle.
If you do have a touchdown this increased heat and current going back up the tungsten carries the contaminants further up the tungsten to where it is below the temperature that dilution in solution can occur.
Brad93
Member
- Messages
- 19,001
- Location
- Essex, United Kingdom
Tbh mate I don’t I’ve been welding for 5 years now and have got past touching down for the most part.You must get through a lot of tungsten Brad.
If I grind my tungsten it’s because it has gone a little blunt at the tip.
I probably only grind right back a tungsten once every now and then.
Richard.
Member
- Messages
- 18,344
- Location
- Cambridgeshire
Brad if that heat tinted spot was a result of touching down it wouldn’t be an inch away from the point it would be contaminated from the point up wards. Look it’s a perfectly straight line exactly where the collet nips it and the rest of the tungsten is bright. That’s nothing whatsoever to do with touching down. it’s not getting sufficient gas protection and it can’t because the collet is nipping it tight. I’d say the op probably wasn’t getting this before because he’s gone from a Fronius torch (wedge collet) where gas can get in due to design to a ck torch which is probably a split collet and this squashes the tungsten and you will get a discoloured tungsten quite often Under a split collet.
I’ve seen this thousands of times where it’s discoloured under a collet with no ill effects and certainly nothing to do with touching down.
Scotch bright isn’t abrasive enough to scratch the likes of tungsten it just brings them back up bright.
Richard.
Member
- Messages
- 18,344
- Location
- Cambridgeshire
It’s not splitting hairs brad it’s disagreeing with each other. Friendly disagreement (from my end anyway)
The op had a Fronius torch which takes the wedged collets (Fronius type) and as you can see he’s said in his post he’s only started getting this heat tint since swapping torches and my guess is he has also gone onto a split collet. All this kinda backs up what I’m trying to say. If he wasn’t getting it before and is now. He’s changed from a wedge Fronius collet, it’s not difficult to work out it’s lack of gas protection from a split collet blocking out gas from hot tungsten. . Nout to do with touching down. Maybe aerospace says cut it back but I’ve also had enough experience with this and seen it enough times. tungstens removed from torches discoloured behind a collets don’t cause problems and clean up perfectly fine if needed.
The op had a Fronius torch which takes the wedged collets (Fronius type) and as you can see he’s said in his post he’s only started getting this heat tint since swapping torches and my guess is he has also gone onto a split collet. All this kinda backs up what I’m trying to say. If he wasn’t getting it before and is now. He’s changed from a wedge Fronius collet, it’s not difficult to work out it’s lack of gas protection from a split collet blocking out gas from hot tungsten. . Nout to do with touching down. Maybe aerospace says cut it back but I’ve also had enough experience with this and seen it enough times. tungstens removed from torches discoloured behind a collets don’t cause problems and clean up perfectly fine if needed.
Richard.
Member
- Messages
- 18,344
- Location
- Cambridgeshire
It would be a boring world if we agreed on everything mate.
Its better to have own views but still have a laugh
Brad93
Member
- Messages
- 19,001
- Location
- Essex, United Kingdom
Of course it’s just friendly debate. Everyone is entitled to their opinion.
I would say to the OP get some CK wedge collects from rapid or one of the CK providers on here.
To get a colour then oxides or nitrides have formed.
They will only form in the presence of oxygen or nitrogen. If you’ve got trapped gas that isn’t inert then something with the setup needs adjustment.
It could be a leaky back cap o ring, air trapped in the back cap, leak through the collet who knows.
But if you start welding exotics or even aluminium that could result in issues.
I would say to the OP get some CK wedge collects from rapid or one of the CK providers on here.
To get a colour then oxides or nitrides have formed.
They will only form in the presence of oxygen or nitrogen. If you’ve got trapped gas that isn’t inert then something with the setup needs adjustment.
It could be a leaky back cap o ring, air trapped in the back cap, leak through the collet who knows.
But if you start welding exotics or even aluminium that could result in issues.
Maker
Most folk just call me; Orange Joe
- Messages
- 10,597
- Location
- Keeler crater
I thought I'd test Richard's theory;
A tiny brass ferrule crimped onto the tungsten should make a band of oxide under the collar and under the ferrule. After a minute or so of welding it looked like this;
That's about what I was expecting but I did contaminate the tip of the tungsten so I got s fresh one and took a blowtorch to it;
The oxide layer looks similar (though more distinct) and definitely isn't caused by tip contamination. No idea why there's no oxide in the middle where the flame was on it?
And finally here's three tungstens at about 60x magnification, cleaned with, from left to right, fine sandpaper, scotchbrite and nothing.
Scotchbrite doesn't touch it (Didn't do a brilliant job of cleaning it either to be honest).
A tiny brass ferrule crimped onto the tungsten should make a band of oxide under the collar and under the ferrule. After a minute or so of welding it looked like this;
That's about what I was expecting but I did contaminate the tip of the tungsten so I got s fresh one and took a blowtorch to it;
The oxide layer looks similar (though more distinct) and definitely isn't caused by tip contamination. No idea why there's no oxide in the middle where the flame was on it?
And finally here's three tungstens at about 60x magnification, cleaned with, from left to right, fine sandpaper, scotchbrite and nothing.
Scotchbrite doesn't touch it (Didn't do a brilliant job of cleaning it either to be honest).
brockenhammer
Member
- Messages
- 274
- Location
- Freiburg, Germany
Hi,
I guess the tungsten stays hot for a longer period of time near the also hot collet and collet body.
When afterflow stops the coloration starts but just here because the tip cools down faster.
It´s just a theory. Maybe an increased afterflow time can proof it.
I guess the tungsten stays hot for a longer period of time near the also hot collet and collet body.
When afterflow stops the coloration starts but just here because the tip cools down faster.
It´s just a theory. Maybe an increased afterflow time can proof it.
Mid Wales welder
Welder coding and NDT services
- Messages
- 672
- Location
- Powys, U.K.
Nice experiment, very informative.
Tinbasherdan
Bodger in chief
- Messages
- 7,383
- Location
- Bolton, England
To be fair Brad, if you’re on about aerospace of the British variety, I’ve been there too and if I chucked half of what they tell you to away anywhere else, I’d be sacked in about 30 seconds. Essentially unlimited tooling budgets are great
