Bad tungsten causing sparks and porosity on mild steel?

[Mach_Zero]

I'm new at tig and I've mostly been practicing on aluminum. I got some mild steel stock and decided to run a bunch of beads and some lap joints (DC of course), but I started having some weird issues.

I was getting lots of sparks and priority even when not using filler and just moving the puddle around. I spent the last two days trying to figure out what's going on and looking for leaks in my argon line. I even took apart my machine and checked the solenoid and the torch port. All good.

I've been using 2% ceriated since that's what came with my machine. But today my shipment of CK LaYZr rods came in so I figured I'd try it out. The results below show the difference.

Settings are exactly the same:
Mild steel 1/8" (two pieces welded together though so the thickness is actually 1/4")
90 Amps
No filler
Both tungsten are 3/32" so the exact same collet for both

I ran the top bead with the 2% ceriated. Switched to the CK, then ran the other bead. Quite the difference. The top one is all grainy and uneven: sunken in some areas, raised in other areas. The bottom one is perfectly flat and smooth (since no filler used, this is what I expected).

The 2% ceriated was freshly ground but the shank probably wasn't clean and had some oxides on it from a previous mistake. Could that cause it? Still weird.

[shovelon]

Check your collet and collet body conditions. The parts that come with the factory torch are atrocious. I order made in usa from TecTorch for my aircooled torches and they flow argon much better.

[Mach_Zero]

Check your collet and collet body conditions. The parts that come with the factory torch are atrocious. I order made in usa from TecTorch for my aircooled torches and they flow argon much better.

Good idea. I suppose it also can be intermittent issues with argon coverage. Maybe when I switch out the tungsten it shifted the collet to a better position?

I have a couple new collets on the way but I haven't ordered a collet body. I figured the body has more mass and doesn't wear as quickly and the thin collets. Should I upgrade? Those wedge collets from CK look interesting.

[G-ManBart]

How are you cleaning your metal? It looks like something fairly coarse was used, and sometimes that means junk gets left behind to contaminate your weld. The close you can get it to a mirror before wiping down with acetone, the better. The shinier it is, the less places there are for contaminants.

The top bead looks like what happens when people forget (not me, I never do that....lol) to turn on the gas or check the flow rate, or accidentally try DCEP on steel...that brown, nasty coating. Are you sure the collet is in properly....with the skinny part forward? They'll work backwards but the gas flow is drastically reduced.

You have 1/4" steel....turn the machine way up....running something low like 90A simply won't help anything at all. For some reason many new folks think they'll be safer setting the machine low and then struggle. 1 amp per thousandth of an inch of stock is the general rule....you don't have to go that far, but something like 150A would be a lot more in the ballpark for just getting a puddle started.

Tri-mix tungstens like the CK LAYzr are great for robots or people who really, really know what they're doing. Arc gap is a critical factor in making the most of them....probably not the strong suite for anybody just starting out. I've tried several brands of the tri-mix style and the only difference I see is that they're a touch better at holding a point on AC. The difference is so minor I don't think it's worth the added cost. For everything else you would make your life a lot simpler by sticking to 2% lanthanated until you've got a lot more experience....and it'll be a lot cheaper.

[Munkul]

Something gas related, as most TIG problems are.

[BillE.Dee]

What is the gas ? What is the gas flow ? What is the tungsten to work distance ? What is the stickout ? What size cup ?

[Mach_Zero]

How are you cleaning your metal?

I used a 120 grit sandpaper disc on a drill attachment. I could definitely get it cleaner but still both beads were run using the exact same conditions.

The top bead looks like what happens when people forget (not me, I never do that....lol) to turn on the gas or check the flow rate, or accidentally try DCEP on steel...that brown, nasty coating. Are you sure the collet is in properly....with the skinny part forward? They'll work backwards but the gas flow is drastically reduced.

Definitely using the same gas settings. I had turned the flow rate up slightly since I was worried it wasn't getting good coverage. Possibly a bad regulator (crappy cheap regulator that came with the machine). I was running just under 20cfh but I I tried from 10 all the way up to 40 in my wild goose chase with no real change before switching the tungsten. I'm using a #8 cup with way less stickout than I can run just to be safe. Stickout for both was 3/16th and I had to tilt my head over just to see the puddle. Not how I usually set up my stickout but just for the testing. Stickout was the same for each bead in the picture. I literally measured it with my ruler each time. Collet was installed correctly each time and I didn't break down the torch when switching tungsten (but it could have shifted around when I loosened the back cap to swap tungstens).

You have 1/4" steel....turn the machine way up....running something low like 90A simply won't help anything at all.

Yeah I probably could turn it up but I don't think low amperage should cause sparks and porosity as long as there's good argon coverage right? The reason I had it at 90 was because I was trying to practice that lap joint on these 1/8" pieces before and too much current would blow out the top edge too much. But I never really got to the point where I can dial in the right current since I got to this porosity sparks issue right away. I'll play around with current settings now though. This piece is just scrap anyway lol

Tri-mix tungstens like the CK LAYzr are great for robots or people who really, really know what they're doing. Arc gap is a critical factor in making the most of them....probably not the strong suite for anybody just starting out. I've tried several brands of the tri-mix style and the only difference I see is that they're a touch better at holding a point on AC. The difference is so minor I don't think it's worth the added cost. For everything else you would make your life a lot simpler by sticking to 2% lanthanated until you've got a lot more experience....and it'll be a lot cheaper.

Damn that's kind of a bummer. I do try to keep a tight arc, but I'm still getting used to tig. I did read that the trimix are better for robotic welding but saw a recommendation online that they were pretty solid for a wide range of applications, mostly low current. But I tend to weld low current. I bought a ten pack of the LaYZr stuff. I guess I can get some 2% lanthanated. I'll go through plenty in my practice anyway.

What is the gas ? What is the gas flow ? What is the tungsten to work distance ? What is the stickout ? What size cup ?

Bottle is marked pure argon but I was wondering for a while if it was accidentally filled with a mix. I doubt it now though because it would be much worse than this.

I have messed with the gas flow in my testing and settled around 18cfh for this #8 cup. No gas lens and a 3/32 tungsten. Stickout was measured for each bead to be 3/16. I know I can go longer on the stickout but I was really making sure it had good coverage for these tests.

[Kelvin]

The reason I had it at 90 was because I was trying to practice that lap joint on these 1/8" pieces before and too much current would blow out the top edge too much.

If you're 'blowing out the top edge' on a lap joint, that suggests to me that you're not putting your heat where it needs to be. In a lap joint, you should focus most (say 2/3 of) your heat on the bottom piece. Once you get a puddle started on the bottom piece, work the edge of the puddle over toward the edge of the top piece in the lap joint. The puddle -- not your arc -- should be what melts the edge of the top piece in a lap joint. Even though both pieces are the same thickness, the bottom piece is, in effect, "bigger" because you're starting a puddle in the middle of the bottom piece, whereas you're starting a puddle on the edge of the top piece.

Think about where the heat is escaping to the surrounding metal ... on the bottom piece in a lap joint, the heat has two avenues of escape, but on the top piece, where you're melting an edge, the heat has only one avenue of escape. Hence, the heat "piles up" on the edge of the top piece and blows out, as you found...this is why you need to work on establishing a puddle on the bottom piece first in a lap joint.

On a more general level, with TIG, you're usually better off giving it more throttle for a shorter length of time, than in giving it less throttle for a longer time, due to "heat soaking" ... this is especially true with aluminum but also true with steel. So before you argue with the advice you've been given, try it.

[Mach_Zero]

If you're 'blowing out the top edge' on a lap joint, that suggests to me that you're not putting your heat where it needs to be. In a lap joint, you should focus most (say 2/3 of) your heat on the bottom piece. Once you get a puddle started on the bottom piece, work the edge of the puddle over toward the edge of the top piece in the lap joint. The puddle -- not your arc -- should be what melts the edge of the top piece in a lap joint. Even though both pieces are the same thickness, the bottom piece is, in effect, "bigger" because you're starting a puddle in the middle of the bottom piece, whereas you're starting a puddle on the edge of the top piece.

Think about where the heat is escaping to the surrounding metal ... on the bottom piece in a lap joint, the heat has two avenues of escape, but on the top piece, where you're melting an edge, the heat has only one avenue of escape. Hence, the heat "piles up" on the edge of the top piece and blows out, as you found...this is why you need to work on establishing a puddle on the bottom piece first in a lap joint.

On a more general level, with TIG, you're usually better off giving it more throttle for a shorter length of time, than in giving it less throttle for a longer time, due to "heat soaking" ... this is especially true with aluminum but also true with steel. So before you argue with the advice you've been given, try it.

Thanks for the advice Kelvin! That makes a lot of sense. I'm still new at this so I'm just trying to figure it out.

I in no way was arguing with the advice though. I didn't say I would keep using 90A despite the advice. I just tried to explain my thought process to generate some good discussion. And it led to you giving me some great feedback and now I understand much better. Hope I didn't come across as arrogant. I definitely don't know what I'm doing but it's been really fun learning and discussing it with all of you.

[G-ManBart]

I used a 120 grit sandpaper disc on a drill attachment. I could definitely get it cleaner but still both beads were run using the exact same conditions.

Just to eliminate it as a variable, try to get a piece super clean...like a mirror if possible, then wipe down with acetone. It may not help, but you'll know for sure it isn't contributing to the problem. Sorting TIG issues like this can be frustrating, so the fewer the variables, the better.

Damn that's kind of a bummer. I do try to keep a tight arc, but I'm still getting used to tig. I did read that the trimix are better for robotic welding but saw a recommendation online that they were pretty solid for a wide range of applications, mostly low current. But I tend to weld low current. I bought a ten pack of the LaYZr stuff. I guess I can get some 2% lanthanated. I'll go through plenty in my practice anyway.

The LaYZr tungstens are very good...don't get me wrong...they're just a bit overkill for steel and learning/practicing. Since they're more expensive you might want to save them for when things are going well and/or aluminum where they really shine by holding their point nicely. For steel and stainless you can run either 2% thoriated or 2% lanthanated and have zero issues....and they're cheaper. I generally suggest 2% lanthanated because they work really well on everything and it's one less thing to think about.

Bottle is marked pure argon but I was wondering for a while if it was accidentally filled with a mix. I doubt it now though because it would be much worse than this.

I have had a couple of bottles marked 100% argon that were slightly contaminated with something else. It wasn't terrible on steel, but just awful on aluminum....the steel results weren't too different from what you're seeing. If you exhaust the other possibilities it wouldn't hurt to talk to the gas supplier....they might even loan you a very small bottle to confirm/deny a gas issue with the bottle you have now.

[Mach_Zero]

Just to eliminate it as a variable, try to get a piece super clean...like a mirror if possible, then wipe down with acetone. It may not help, but you'll know for sure it isn't contributing to the problem. Sorting TIG issues like this can be frustrating, so the fewer the variables, the better.

Great idea. I'll do that. I welded a corner joint with the same steel using the LaYZr today and it didn't spark at all but it did leave some little deposits on the surface of the bead. So it's likely that I'm not getting it too clean.

The LaYZr tungstens are very good...don't get me wrong...they're just a bit overkill for steel and learning/practicing. Since they're more expensive you might want to save them for when things are going well and/or aluminum where they really shine by holding their point nicely. For steel and stainless you can run either 2% thoriated or 2% lanthanated and have zero issues....and they're cheaper. I generally suggest 2% lanthanated because they work really well on everything and it's one less thing to think about.

Oh they were actually cheaper than the lanthanated on Amazon. The 10 pack 3/32 from CK are like 24-25 bucks and I got this 10 pack of CK LaYZr for 20. So I didn't think I was spending extra to get them lol. But good to know that they're good electrodes!

I have had a couple of bottles marked 100% argon that were slightly contaminated with something else. It wasn't terrible on steel, but just awful on aluminum....the steel results weren't too different from what you're seeing. If you exhaust the other possibilities it wouldn't hurt to talk to the gas supplier....they might even loan you a very small bottle to confirm/deny a gas issue with the bottle you have now.

Interesting. For me it's the other way around. I got a great looking aluminum weld. No soot or anything on it. Just used 30% EP balance and it looked great. Then I got those weird results with steel.

I wonder if it could also have something to do with the stock crappy vulcan cable. I have to sling it over my shoulder and really muscle it into position. Maybe I kinked it or something? I don't know. The new CK superflex cable is on the way so we'll see.

I really appreciate your help G-ManBart!

[shovelon]

Great idea. I'll do that. I welded a corner joint with the same steel using the LaYZr today and it didn't spark at all but it did leave some little deposits on the surface of the bead. So it's likely that I'm not getting it too clean.




Oh they were actually cheaper than the lanthanated on Amazon. The 10 pack 3/32 from CK are like 24-25 bucks and I got this 10 pack of CK LaYZr for 20. So I didn't think I was spending extra to get them lol. But good to know that they're good electrodes!




Interesting. For me it's the other way around. I got a great looking aluminum weld. No soot or anything on it. Just used 30% EP balance and it looked great. Then I got those weird results with steel.

I wonder if it could also have something to do with the stock crappy vulcan cable. I have to sling it over my shoulder and really muscle it into position. Maybe I kinked it or something? I don't know. The new CK superflex cable is on the way so we'll see.

I really appreciate your help G-ManBart!

You really might want to invest in one of these. Checks your gas flow at the torch. If it does not match the gauge you need to figure out why.

[shovelon]

Good idea. I suppose it also can be intermittent issues with argon coverage. Maybe when I switch out the tungsten it shifted the collet to a better position?

I have a couple new collets on the way but I haven't ordered a collet body. I figured the body has more mass and doesn't wear as quickly and the thin collets. Should I upgrade? Those wedge collets from CK look interesting.

True collets wear out faster than collet bodies. But these standard ones are crap. I had trouble with them for both AC and DC work, so I upgraded to gas lens and collets.

You could also have a bad torch. Loosen the back cap slightly, pull the front end parts, and see if the back cap chocks off the gas port. If good reassemble, pull out the back cap, tungsten, and collet and look in to see if the collet body is choking off the gas port. Ideally the gas port would be right in between the back cap and collet body. I the collet is twisted, bulged, or smashed it could allow the back cap to move forward and choke off the gas. Also check the back cap for good o-ring, and no holes in the body.

[Mach_Zero]

You really might want to invest in one of these. Checks your gas flow at the torch. If it does not match the gauge you need to figure out why.

Thanks! I'll get one of those. I'm wondering if I should upgrade the regulator too. The one I have is one of those cheap ones that have two gauges and says Argon/CO2. The torch looks pretty good and I can feel flow coming out but I would also like to get a gas lens eventually.

[shovelon]

Thanks! I'll get one of those. I'm wondering if I should upgrade the regulator too. The one I have is one of those cheap ones that have two gauges and says Argon/CO2. The torch looks pretty good and I can feel flow coming out but I would also like to get a gas lens eventually.

The ones I get are $15 with free shipping on eBay and are very accurate. Just make sure it is graduated in square cubic feet, no liters. As far as the flow regulator it might dead on accurate so I would wait to confirm flow at torch.

[Willie B]

Ever seen a kitchen faucet with aerator missing? Water blasts out, splashes all over the place. Screw on a clean aerator. all the splattering goes away. A gas lens is a faucet aerator. Helps calm the turbulence. I use one mostly ALL welds.

Are you sure you are welding Electrode Negative?

[Welder Dave]

Maybe bad gas if worse on aluminum. Worked at a place that had a lot of argon returned because they didn't purge the cylinders before they were filled. Expensive mistake. Something happened and their CO2 bulk tank got contaminated. I thought the EPA was going to show up with the huge cloud of CO2 being released into the atmosphere.

[12V71]

Ever seen a kitchen faucet with aerator missing? Water blasts out, splashes all over the place. Screw on a clean aerator. all the splattering goes away. A gas lens is a faucet aerator. Helps calm the turbulence. I use one mostly ALL welds.

Are you sure you are welding Electrode Negative?

Polarity is a good point, Positive polarity is going to decimate the tungsten. IIRC, it takes a 1/4" tungsten to handle 200 amps DCEP.

[Mach_Zero]

Ever seen a kitchen faucet with aerator missing? Water blasts out, splashes all over the place. Screw on a clean aerator. all the splattering goes away. A gas lens is a faucet aerator. Helps calm the turbulence. I use one mostly ALL welds.

Are you sure you are welding Electrode Negative?

Yeah I'm definitely using electrode negative. Don't think the machine would put any gas at all if I plugged the torch into the positive side since the gas goes through the diesel connector. I'll probably get a gas lens kit but I'm just not sure if it's a technique problem. I welded some more steel today and it didn't shoot sparks at first but I think I overheated the part and oxides formed. Got some more porosity and sparks a little later. But I'll try to clean the metal some more. It doesn't help that I'm trying outside corner joints when I'm not a good enough welder to do that yet lol.

What would be be good weld joint to do so I can post a picture for feedback? Simple butt joint, T joint?

Polarity is a good point, Positive polarity is going to decimate the tungsten. IIRC, it takes a 1/4" tungsten to handle 200 amps DCEP.

Yeah I mean I'll check again but I'm definitely plugging in the torch on the EN side. I wouldn't get any gas at all if I plugged the torch into the positive side since the gas goes through the dinse connector. I think it's possible I'm just get using a poor technique. Maybe also some bad gas? But my aluminum welds turn out better than steel so it wouldn't make any sense.

[Willie B]

You have more spatter than I expect. The whole area is blackened. Either you are holding too long an arc, too much stickout, an air leak in the torch, or contaminated tungsten.

Grinding tungsten everybody does something different. Some will say I do it wrong. Where the collet grips the tungsten to the point is perhaps 3/4". I grind that length if contaminated. I use a dedicated bench grinder with two grooves worn in the fine stone. It lays on its back so the wheels turn away from me. I grind a handfull of tungstens to shape, then switch grooves to perfect the point. Tungsten for steel gets a needle sharp point, aluminum gets a more blunt shape.

In the torch the white washer, then gas lens tightened finger tight, then ceramic cup I often use a #7 cup. Gas flow usually about twice the CFH as cup size.
Tungsten, collet, washer & tail cap last. Don't get long with stick out if you don't have to.

Arc length 1 thru 1-1/2 times tungsten diameter.

Outside corners are tough. I believe gas fails to get into the joint & stay pure. A block of aluminum clamped inside the corner when you weld it will trap gas that might blow around inside the box. Grind the corner of this aluminum block.

[Willie B]

Polarity is a good point, Positive polarity is going to decimate the tungsten. IIRC, it takes a 1/4" tungsten to handle 200 amps DCEP.

I wonder about a machine malfunction sticking on AC.

I experimented once DC EP for aluminum. The sparks were like sparklers on independence day! Aluminum AC with balance reversed IE 80/20 EP will spark bad! 80/20 EN might not do enough to cathodically clean (I learned that from Shovelon), but no fireworks.

I haven't figured this out. Can't help thinking 5 minutes with Shovelon, you'd be fixed.

You have one minor problem, figure it out, you're golden.

Buy me a round trip plane ticket, I'll get there, call Shovelon, I'll fix you.

[Welder Dave]

I think the easiest thing to do is just try a new, maybe different tungsten?

[Mach_Zero]

I think the easiest thing to do is just try a new, maybe different tungsten?

Lol thanks Welder Dave. I mean that was the entire premise of my post though. I tried a new tungsten and it worked way better. So I was just asking if it's possible for an electrode to go bad.

Ultimately I think the issue is that even though I had ground in a new tip, I hadn't cleaned the oxides on the shank of the tungsten electrode that I thought was the problem.

[Mach_Zero]

I haven't figured this out. Can't help thinking 5 minutes with Shovelon, you'd be fixed.

You have one minor problem, figure it out, you're golden.

Buy me a round trip plane ticket, I'll get there, call Shovelon, I'll fix you.

Lol that would be awesome (if I could afford it).

I'm gonna super clean some mild steel coupons and super clean the tungsten. Then I'll weld a T joint or something similar and post the results.

So far it works great on aluminum so that's why I've been confused. Everything I've read or seen online has said that tig welding aluminum should be more difficult but now in my experience.

[Willie B]

Lol that would be awesome (if I could afford it).

I'm gonna super clean some mild steel coupons and super clean the tungsten. Then I'll weld a T joint or something similar and post the results.

So far it works great on aluminum so that's why I've been confused. Everything I've read or seen online has said that tig welding aluminum should be more difficult but now in my experience.

Or, if you can get him to give you his phone number.......Little cost.

He bailed me out a few times when I was new. He has forgot more than I will ever know.

You are working well on aluminum. It is nagging me that your machine is stuck on AC. Sparks are something I haven't seen except on EP half cycle. Too much EP causes too much heat to flow to the tungsten. It burns up. Might explain spatter I'd expect stick welding, or MIG with CO2.