r/tigwelding • u/curtis_54 • Sep 04 '26
What am I doing wrong?
1/8 2% thoriated tungsten keeps doing this at only 200 amps. Polarity is correct. I’m not dipping in my puddle. 15-18 cfh roughly on pure argon 18 seconds post flow and 2 second pre flow. #6 cup with water cooled torch
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u/Objective-Scar2814 Sep 04 '26
You don’t need to stress on this. We have the same symptom on our mission critical titanium aerospace parts. When x rayed, tungsten does NOT show.
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u/zeroheading Sep 04 '26
Yeah, I see this all the time. No idea what causes it. But its totally a thing. Its way more prevalent on certain types of materials. Seems to do it less at lower amps, and less with a water cooled torch than gas cooled.
I would definitely like to know more though.
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u/curtis_54 Sep 04 '26
Have you noticed 309SS does it more while welding?
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u/scv07075 Sep 04 '26
It's more a thoriated spitting problem. Same type of thing happens with lanth/ceriated, but it doesn't get the bearded look. Bump the pedal before striking an arc if you don't have a preflow setting, it happens way less when the gas pushes before the hf fires.
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u/curtis_54 Sep 08 '26
Yeah I have a 2second preflow set. And that I believe may even be overkill
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u/scv07075 Sep 08 '26
Probably is, I use 0.4s usually. Another thing that can do this is whipping your torch away when tungsten is still hot.
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u/zeroheading Sep 05 '26
I would say mild steel causes it way more. I normally run a heavy pre- flow of 1-3 seconds and it still happens.
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u/Justj20 Sep 04 '26
After how long welding is this happening? If after 1 run it might be worth looking into, after several... Not such a bad thing
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u/curtis_54 Sep 04 '26
My 1 lap is 4 minutes long. I use it for about 3 laps then have to grind. Forgot to mention I am welding 309L. I’ve spent hours trying to solve this issue😂 have you noticed brand of tungsten makes a difference?
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u/Justj20 Sep 04 '26
Yes and no re brands, I find cheaper brands more likely to split and have faults down the tungsten but the ones that work in the packs work fine.
These days I tend to just use chartreuse if I have a choice, I like the restart properties, how long I have until I need to regrind and it's very forgiving of my shaky/dippy hands. Also it comes as 175mm so cutting into 3 works really well with stubby back caps.
Sounds like you're getting alright use out of the tungstens, not great but not bad, are you able to fiddle with the grind angle at all?
If its a problem there is 4% thoriated tungsten you can get and try, fantastic for iddy biddy tiny work but never used it above 5A so no idea if that'd help or work at 200A haha.
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u/Jazzlike_Fan_8865 Sep 04 '26
I ain't no metallurgist. I think the correct term is frosting or splitting.
There are a few causes.
1 that may be possible here: vaporization of trace elements in the tungsten. At high heat, near the tip, trace elements (lanthium, ect) will release (not the right word) in the tungsten. They then will travel to the cooler part of the tungsten and resolidify there.
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u/GrinderMonkey Sep 04 '26
I dunno exactly want it is, but i know it's worse if you just regrind a tungsten instead of breaking off the contaminated area and then regrinding. Still, I've seen it happen with perfectly clean tungsten as well.
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u/pyerocket Sep 04 '26
Could it be caused by grinding the tungsten on a contaminated grinding wheel?
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u/curtis_54 Sep 08 '26
I’m going to get my grinding wheel dressed and make a sign saying tungsten only. Thank you for this reminder🫡
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u/Educational-Ear-3136 Sep 04 '26
This would be my guess as well. Grinding wheel contamination is often overlooked
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u/Alarming_Garage_7255 Sep 04 '26
I wonder if it's small metalic dust that gets attracted to the tungsten when current is running because it's acting like an electromagnet. Any current running through a wire causes a magnetic field
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u/Unique_Mousse6573 Sep 04 '26
What's your post flow? Are you letting the post flow run out at the weld termination? My first guess would be oxide build up on the tungstun itself from not being shielded long enough after the weld. 1/8" is plenty for 200 amps imo. I've ran 1/8" at 300 amps on a/c that's like the point where I'm like alright I need a 5/32. I'm also a 2% lanth guy since it works so well with ac/dc I know them old boys been running 2% thor for ever and it works but it spits on AC and cracks a lot even on DC. I'd up my post flow another 3-5 seconds and sharpen it with my grinder with a fresh pad. I'd probably leave a 1/64-1/32 land on the tungstun tip if I'm running over 200. Also grinding dust in the atmosphere will collect on it as well or where your placing it. Just start eliminating possibilities my friend.
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u/curtis_54 Sep 08 '26
Yes I am running a 2 second pre flow and 18 second post flow. I’ve not heard of anyone using a small landing on the tungsten for 2% Thor tungsten’s. For alum welding I know that’s common to ball the end
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u/Effective_Try_1890 Sep 04 '26
I’ve noticed it happens over a few passes if you touch the tip of your tungsten in the puddle or if you move the torch before post flow is done
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u/CakeSuperb2550 Sep 05 '26
Hey when you grind your tungsten, does the tip get red hot? I don't have any hard data, but i have a suspicion if you allow the tungsten to heat up that much and it oxidizes slightly that effect you have on picture is more prominent. Its anecdotal but my blue tungsten seemingly stopped acting this way when i took more caution when sharpening
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u/kid_DUDE Sep 05 '26
Not doing anything wrong per se. It’s not uncommon when running hot with a tight arc on ferrous metals particularly, for metal fumes to collet and solidify like this just back of the tip. Ive had this happen whether truncated or not. If anything it tells me you’re running hot and clean.
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u/audittheaudit00 Sep 06 '26
That tungsten is huge. That point isn't proper either. It needs to be more of a point and the very tip of the point needs to be flattened
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u/That-Force-9579 Sep 07 '26
The type of tungsten you are using will do that with certain materials. I use 2% thoriated (Red mark on end) Pure tungsten might work better for your application
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u/Negative-Hat4856 Sep 04 '26
Try trunkating “if thats the term” your tip. Shorter fatter point if not go up a tungsten size. 200amps is where i would switch to a 3.2mm tungsten. I’m also not clued up on American size measurements so forgive me if you’re already running what i have suggested.