[CE CLECKLER]

I'm fairly new to the whole tig world, but really enjoying figuring it out....the problem I'm having is I have had 2 #8 gas lenses break right at the taper. Both times doing relatively short welds(1" X 1/8" angle steel). Diversion 180, foot pedal, 120 amps, 20 cfh. Also is there something I'm doing, or should be to keep the screen clean it has a little bit of bits on it. Thanks in advance. Courtney.

[MosquitoMoto]

Hey Courtney.

Is it the gas lens or the alumina cup that is breaking? Sounds like the cup. (cups are generally pink and alumina, gas lenses are generally copper/brass)

Are you able to post a pic or two?


Kym

[CE CLECKLER]

yes the pink cup....i might be able to get a pic a this afternoon, but basically right where the pink body necks down from the big internally threaded part to the small outlet, its popping that end off

[MosquitoMoto]

Okay, the cup then.

Is it breaking off clean at the shoulder or is it cracking? Seems quite unusual. I've been Tigging for over a year now and I'm yet to break a single cup.

Someone wiser than I will chime in soon er or later I'm sure.



Kym

[maker of things]

Someone wiser than I will chime in sooner or later I'm sure.
Kym

Until that happens, I too would say that sounds very odd. If the cup is separating into multiple pieces and it wasn't dropped, I would suspect manufacturing defect. Especially since the same thing happened to 2 of them.

The junk getting in the screen is probably from welding on angle iron. If you don't mechanically clean the dark scale off the material before you weld it will cause porosity and spatter. Even just oily/dirty material will emit a lot of debris onto the screen.

[Poland308]

If you take a picture of the broken cup make sure you include a photo of all the parts you used to put your setup together. It could be an issue with having the incorrect spacers.

[Coldman]

Cups should be tightened enough to seal at the back. It is possible to over tighten causing cracking at hi temp. If not over tight then I would suspect quality. Where did you get them from?


Sent from my iPhone using Tapatalk

[exnailpounder]

I have had one crack on me. Welding aluminum and had the torch so hot I could barely hold it. I think the gas lens expanded a bit from getting so hot and it cracked the cup off at the threads. Only time it's ever happened and I may have had it too tight to begin with. As far as getting your screen crapped up...that has only happened to me when trying to weld 400 series stainless with a galvanized coating that was impregnated into the base metal. Regular old mill scale on mild steel just sparks a little and that burnt up scale jumps onto your tungsten like a magnet and craps it up.

[noddybrian]

If you have the wrong insulator & when you tighten the cup it runs out of thread so is tightened to it's last thread on the collet body rather than just snugging up against the torch body rubber it can crack even at relatively low heat inputs - think there was another post relating to this a while back - can't remember the outcome though ( sorry ! )

What torch / gas lens / combo have you - if it's a normal gas lens ( ie not a stubby conversion ) on a #17 / #26 you will usually need 2 insulators ( though there is a single version if you can find it )

[entity-unknown]

Did you put the cup on by hand or with a tool? These are hand tight and not automotive or Grizzly Adams hand tight. If you use the tips of all but your pinky finger to screw them on, you should reduce your leverage a lot so you get a snug fit, not a tight fit. Putting them in the "o-ring" of your thumb and pointer finger might create too much tension.

If it's none of this, then it must be a bad cup. That torch you're threading the cups on is ABS plastic so beyond really over tightening it's impossible for it to break the cup unlike say if those thread were steel, then it could be a bad taper or something, but not with ABS even with a bad taper.

Did you buy them from Jody? I've had light drops with a couple of those cups from him and nothing broke yet. $2.99 plus shipping and if you use the code "HOLIDAY" you'll receive an extra %15 off right now

[CE CLECKLER]

here are some pictures.... i dont think im over tightening....by hand, snug

[CE CLECKLER]

sorry about the focus....not the best camera................maybe the photographer..

[CE CLECKLER]

and no i didnt get them from jody....local (hour drive) supplier, and not a regular stocking item for them.

[exnailpounder]

That's where mine broke too. But it only happened once and never again. You may have gotten a bad run of cups or something. If you are like the rest of us weirdos, you should be a tig horder and have every cup size available in Pyrex and otherwise 10 deep...cups are cheap, probably a fluke. If it keeps happening then I would wonder.

[motox]

cranked down to tight or poor product.

[Oscar]

You're missing a Teflon insulator gasket. Your gas lens gasket you have on now isn't meant to be seated up against the torch by it's lonesome self. There are some that are 1-piece, but yours needs the "stock" insulator gasket.

[soutthpaw]

Composed with Swype on mobile. not responsible for typos.

[Olivero]

Yup, been there done that.

I stopped using below #8 cups, I did an aluminum floor in a walk in fridge, I was there for about 10 hours in the day and I broke..... 4-6 cups I think. all of them had that tapered end. I would weld and weld and weld, cups glowing red hot, I was welding at 140 amps I think, Tigging my day away and every time I as much as bumped the cup it would split right where yours is. after having dried my last supply of tapered cups I put a #8 on and had no issues since then, well, it split last week but that's about 3 months ago I did that.

I am sure they are"supposed to be able to be used" but its just not worth the trouble, seems like I get as good of a gas coverage but it does suck when I have to get in tight corners at which point I might switch to a tapered one but in general, I stick to #8's.

[exnailpounder]

Composed with Swype on mobile. not responsible for typos.

I don't have that extra teflon spacer for my tig torch and I have only cracked one cup in the last 3 years. Your cup threads onto your gas lens so unless air can be pulled through threads and into your shield gas and cause problems, what is that extra little spacer do? I don't use it and have never had a problem with gas contamination. Are we all looking at the same thing here? Don't use a torque wrench to thread your cup onto your gas lens and there shouldn't be any problems. My one and only cup crack off was from welding aluminum for so long that the torch (air cooled) was so hot that I couldn't hold it anymore and only then did my cup crack off...I dug out another cup and screwed it on and I have been using it for the last 3 years.

[Arno]

I don't have that extra teflon spacer for my tig torch and I have only cracked one cup in the last 3 years. Your cup threads onto your gas lens so unless air can be pulled through threads and into your shield gas and cause problems, what is that extra little spacer do?

It keeps the inside of the cup from touching/tightening on the edge of the gas lense body.

The problem depends a lot on various part sizes/tolerances, but if you have a torch that has the insulator a little further down or a gas lense body that's a little on the long side (or a cup that's short-ish) then as you tighten down the cup then the cup and the gas lense body can collide/jam inside the cup where it tapers/necks down.

If this happens then the expanding copper/brass of the gas lense body as it heats up will start to 'push' on the inside of the cup and if it's bad enough will basically fracture and 'pop' the top of the cup off.

The second (actually the standard) teflon ring spaces the cup a little 'off' the end of the brass body so it can never touch even as it expands.

So in some cases it may work to not use the standard insulator if your gas lense body is short enough not to touch the cup, but if it does then you're likely to crack cups left and right and using the normal spacer in the stack-up is advisable.

Bye, Arno.

[C. Livingstone]

Yeah,

And you can undoubtedly and oftentimes go the other way too, and only use the standard insulator, without the one included for the gas lens, which can be redundant and make the torch tip needlessly longer, even though the cup may seat better to the flange-like one designed for the gas lens. And this may keep the gas lens further away from the cup, to prevent your problem.

That's what I'm doing now with a stubby gas lens on a 17 torch, and I believe I did the same thing with a standard gas lens on a 17 torch. But, you will only get a couple of turns to tighten it, unless you want to provide a little relief with a Dremel on the standard insulator, which I suppose could case the gas lens to press up to the cup as it necks down, which seems to be your current problem. But a couple of turns is plenty, as you'll get a bit of an indent there anyway with repeated usage. And I've never had any high frequency leakage at that point by doing this.