# TIG Torch Cups & Gas Lenses question(s)



## graham-xrf (Jun 20, 2021)

Still starting from ignorance, and looking at the stuff one can get in consumables kits. Please forgive how basic these questions are, but they happen when one is purchasing all the stuff to get enough TIG kit together for a weld to happen in the first place!

Cups diameter sizes at the exit seem to range from 4 to 10, this being a count of how many sixteenth inches, though I dare say it may not be all of them. Fairly obvious is that the little pink cups can be longer (L), or quite a lot longer (XL), though going longer seems to be something confined to the smaller sizes. Hence..




1. What are the motivations for these (small & long), other than to reach into a confined spaces?
    Does it force a length of tungsten electrode become "wasted". Are all these really needed? Can one do nearly all with a size 7? Can you use any cup with any size electrode? What is the wisdom about choosing a electrode + cup size combination when considering a weld?

2. We then get a similar scene when the innards are changed to be "gas lenses" type. Various arrangements of trick grids and gauze and seals to persuade a longer column of non-turbulent gas flow. So the question. Does using gas lens remove the need for various lengths? We can see that there are sets of pink ceramic cups that go with gas lens. Are they different from regular ceramic cups? Is it a thing about size compatibility? I guess I am asking whether one has to take care not to get them mixed up with non gas lens types which also happen to be pink?





3. Next we see a series of clear pyrex cups. They obvious difference is that one can see through them.  The presence of these seems to be associated with gas lens kits, so it begs the question. Are clear see-through pyrex cups used in regular TIG (ie. no gas lens).

4. Also seemingly associated with gas lens kits is "stubby". Other than that one chose a short cup, what is the deal with stubby? Is it something that always goes with gas lens?


----------



## 7milesup (Jun 20, 2021)

graham-xrf said:


> . What are the motivations for these (small & long), other than to reach into a confined spaces?
> Does it force a length of tungsten electrode become "wasted". Are all these really needed? Can one do nearly all with a size 7? Can you use any cup with any size electrode? What is the wisdom about choosing a electrode + cup size combination when considering a weld?


The size of the cup is related to tungsten size.  Generally 4 time the tungsten size for cup size.  I.E. 1/16" tungsten = 1/4" cup opening which is a #2 cup.
The gas flow should be about 2.5 times the cup size.  So an 8 cup will equate to a 20cfm gas flow.  If using a gas lens I feel that you can get by with less.
The tungsten electrode should not become wasted with a longer cup.  Only the tip gets fouled.
The larger the electrode obviously dictates the size of the cup to a large extent.  Weld travel speed also dictates cup size.  The larger the cup, the faster you can travel because you are getting better shielding gas coverage.


graham-xrf said:


> Does using gas lens remove the need for various lengths?


No.  Longer cup is for getting into tighter spaces.


graham-xrf said:


> Are they different from regular ceramic cups?


No, not that I know of.


graham-xrf said:


> re clear see-through pyrex cups used in regular TIG (ie. no gas lens)


I believe the clear cups are pressed on and have an o-ring seal.  Gas lens use only in that case to my knowledge.  I honestly have never used them so can't offer much there.


graham-xrf said:


> Other than that one chose a short cup, what is the deal with stubby


Stubby is the size of the thing-a-ma-bob that sticks out the back side of the torch.  Stubby means you can have really short tungsten to get into tight spaces whereas the normal thing-a-ma-bob sticks out quite a ways.  You need to cut your tungsten into short pieces with a diamond cutoff wheel for the stubby thingy.  Lots of technical terms in this paragraph....

I use gas lens exclusively.  I also use the CK wedge collets.  Since switching to them my frustration level has gone way down with getting the collet to hold the tungsten.  https://www.ckworldwide.com/products/wedge-collets


----------



## Aukai (Jun 20, 2021)

I learned something, thank you both....


----------



## GunsOfNavarone (Jun 20, 2021)

I'm a big fan for Furick cups and Edge. The gas lenses they use and large cup size give great gas coverage which in turn, CAN make for an easier time welding, but you'll also burn through more argon as they use around 35 cfm (those smaller ceramic cups might be more around 15 cfm.)
I've been really impressed with the LF line from Edge (Laminar flow) but there are also limitations to how much amps you can run through them (I believe 180) Some believe it's better to learn with ceramic as they won't mask a poor welding job as much as the gas lens type. I'm pretty sure you won't be walking the cup, but you can't do that with pyrex either.
There are a lot of cheap Chinese knock offs out there, but you also don't want a turbulent flow either...I can't speak of how the knock offs are with that.


----------



## akjeff (Jun 20, 2021)

GunsOfNavarone said:


> I'm a big fan for Furick cups and Edge. The gas lenses they use and large cup size give great gas coverage which in turn, CAN make for an easier time welding, but you'll also burn through more argon as they use around 35 cfm (those smaller ceramic cups might be more around 15 cfm.)
> I've been really impressed with the LF line from Edge (Laminar flow) but there are also limitations to how much amps you can run through them (I believe 180) Some believe it's better to learn with ceramic as they won't mask a poor welding job as much as the gas lens type. I'm pretty sure you won't be walking the cup, but you can't do that with pyrex either.
> There are a lot of cheap Chinese knock offs out there, but you also don't want a turbulent flow either...I can't speak of how the knock offs are with that.


Another Furick fan here. A Furick 8 is what I weld with 90% of the time. Works great on steel and aluminum. Pretty much about the biggest cup I'd run on AC. Doing oddball stuff like stainless and chromo, I'll switch to something like a Monster Cup if I need a big cloud, or have to run a lot of stickout.


----------



## General Zod (Jun 20, 2021)

7milesup said:


> The size of the cup is related to tungsten size.  Generally 4 time the tungsten size for cup size.  I.E. 1/16" tungsten = 1/4" cup opening which is a #2 cup.
> The gas flow should be about 2.5 times the cup size.
> 
> Stubby is the size of the thing-a-ma-bob that sticks out the back side of the torch.



Sorry bud a couple of corrections:

The size of the cup is not necessarily correlated to the tungsten size, it is _correlated to the argon coverage one desires_.  I could be using a 1/16" tungsten welding a stainless steel header tube 1/16" thickness @ 45A, and I could and would very easily slap on a _*#18*_ cup. Why? Stainless doesn't need a lot of amps, but conducts heat so slowly you need a lot of argon coverage while the weld bead cools to prevent severe oxidation. 4x the cup size does not work either if you are at, say the upper end of a 1/8" tungsten carrying 260-270A of DC current. That would be a 1/2" cup (#8), which would be hardly adequate for the size of puddle 250A produces (I know because I have a 400A TIG welder, so I've seen the different sized puddles different amperages can produce).

I've yet to see ANYWHERE a #2 up.  Smallest I've seen typically available is a #4.  And unless you're doing tiny welds and only doing them ¼" long at a time, you need at least a #5 or #6, and that is if you are welding a metal that is not highly reactive.

"Stubby" refers to a class of collet bodies (and related consumables), not the back-caps that stick out the back of the torch. Those are called "back caps".  

Stubby collet bodies (and collets/cups of course) are used on *17/18/26* style torches, to shorten the length of the front-end parts, for better visibility/maneuverability.  
Stubby set-up's use 9/20 series consumables (what CK Worldwide calls "2-series) if the are not gas-lens type, or 4-series consumables (if they are gas lens types); in other words,  the stubby collet bodies themselves come in two flavors:

Standard, non-gas lens, left.  Gas lens right:







The main difference is the standard, non-gas, lens stubby collet bodies use standard 9/20 cups, and the stubby gas lens collet bodies use 9/20-series gas lens cups (gas lens cups have a larger base to fit the gas lens collet bodies).  The other obvious difference is that they require different sized white teflon heat insultators.






> 1. What are the motivations for these (small & long), other than to reach into a confined spaces?
> Does it force a length of tungsten electrode become "wasted". Are all these really needed? Can one do nearly all with a size 7? Can you use any cup with any size electrode? What is the wisdom about choosing a electrode + cup size combination when considering a weld?



Longer cups are for extended reach, where you can't get the torch near the weld joint, nothing more.  Tungsten does not become wasted.  A #7 cannot suffice for highly reactive metals.  Standard aluminum and mild carbon steel are fine, but go ahead and try welding stainless steel with nothing more than a #7, and we'll wait for the inevitable "_what am I doing wrong?_" help thread. 


> 2. We then get a similar scene when the innards are changed to be "gas lenses" type. Various arrangements of trick grids and gauze and seals to persuade a longer column of non-turbulent gas flow. So the question. Does using gas lens remove the need for various lengths? We can see that there are sets of pink ceramic cups that go with gas lens. Are they different from regular ceramic cups? Is it a thing about size compatibility? I guess I am asking whether one has to take care not to get them mixed up with non gas lens types which also happen to be pink?



Yes and no.  Yes to a certain extent, because  flowrate-for-flowrate, a gas lens setup will have better coverage than a standard  setup, so that you can greatly extend the tungsten past the cup orifice, even over 1" in some instances, but even then that does not guarantee that you'll be able to sneek the torch body into the crevice you need to.  In such a case, it may only be remedied with an extended-cup nozzle, simply because it is much more compact......The cups that go with gas lens collet bodies are different from the standard ones.  They have a larger diameter than standard cups, and thus will not interchange, at all.



> 3. Next we see a series of clear pyrex cups. They obvious difference is that one can see through them.  The presence of these seems to be associated with gas lens kits, so it begs the question. Are clear see-through pyrex cups used in regular TIG (ie. no gas lens).



They can be, but it is not a common scenario.  They are usually paired with a dedicated gas lens collet body.   In the picture you posted, you can see they are paired with a gas lens collet body, and the seal is obtained using an O-ring (an o-ring is not needed with the standard pink cups because those thread onto the collet body).  

Here is a set-up from WeldTec/TecTorch that uses a clear cup, but NO gas lens (at the top) vs a more "typical" that uses gas lens collet bodies:






As you can see above, it is a specialized, dedicated set-up that uses special collet bodies that look like standard variants, but are machined to accept an O-ring to seal the clear up.





> 4. Also seemingly associated with gas lens kits is "stubby". Other than that one chose a short cup, what is the deal with stubby? Is it something that always goes with gas lens?




See my response above where I made the correction regarding "stubby" vs "back caps".


----------



## cathead (Jun 21, 2021)

I have both 3/32 and 1/8 tungstens.  Is there anything wrong with using the 1/8 for lighter work as long as I use the appropriately sized cup
for the job?


----------



## akjeff (Jun 21, 2021)

cathead said:


> I have both 3/32 and 1/8 tungstens.  Is there anything wrong with using the 1/8 for lighter work as long as I use the appropriately sized cup
> for the job?


Nothing wrong with doing that at all. With a really sharp tip you can weld thin stuff pretty well, once you get a feel for it. For me, thin stainless is another matter. I usually drop down to a 1/16", as I just don't do it often enough to develop the finesse needed.


----------



## 7milesup (Jun 21, 2021)

General Zod said:


> Sorry bud a couple of corrections:
> 
> The size of the cup is not necessarily correlated to the tungsten size, it is _correlated to the argon coverage one desires_.  I could be using a 1/16" tungsten welding a stainless steel header tube 1/16" thickness @ 45A, and I could and would very easily slap on a _*#18*_ cup. Why? Stainless doesn't need a lot of amps, but conducts heat so slowly you need a lot of argon coverage while the weld bead cools to prevent severe oxidation. 4x the cup size does not work either if you are at, say the upper end of a 1/8" tungsten carrying 260-270A of DC current. That would be a 1/2" cup (#8), which would be hardly adequate for the size of puddle 250A produces (I know because I have a 400A TIG welder, so I've seen the different sized puddles different amperages can produce).
> 
> ...


I figured you would chime in.

My reference to cup size is a general rule of thumb.  Rules of thumb can generally be broken...

I know enough to be dangerous, that is my story, and I'm sticking to it.


----------



## Janderso (Jun 21, 2021)

7milesup said:


> I know enough to be dangerous, that is my story, and I'm sticking to it.


You are a true gent. 
Nice way to communicate.
I'm reading this thread with interest as I am learning how to sharpen tungsten 
Thank you General.


----------



## G-ManBart (Jun 21, 2021)

cathead said:


> I have both 3/32 and 1/8 tungstens.  Is there anything wrong with using the 1/8 for lighter work as long as I use the appropriately sized cup
> for the job?



Generally speaking that's fine, but there are times when it won't terribly work well.  For example, if you're trying to weld at low amperages you might get an inconsistent start or the arc wandering.  That just shows you're not really running enough amperage for the tungsten diameter.  If you put a really sharp point on the tungsten it will help minimize the arc wander in situations like that.  It seems more noticeable if you're trying to do something like an edge weld on thinner material....the arc just won't focus on the edge like you need it to be.  If you can't sharpen the point enough to get a consistent start and no arc wander, then it's just time to drop a tungsten size.


----------



## G-ManBart (Jun 21, 2021)

General Zod covered most of the things I was thinking, but I thought of a couple things that might be helpful.

These are just really broad generalizations, so nothing absolute.

Most people stick to roughly 2x the cup diameter for argon flow....so a #8 cup gets around 16cfh.  If you use too high of a flow you can cause turbulence and get porosity.  A gas lens will usually let you get away with a lower flow than a standard setup (other than the huge cups for stainless), but that's just a bonus, not the reason they exist. 

For mild steel you can put a #7 or 8 cup on and pretty much forget about it until you're trying to get into small spaces.  For aluminum you can stick with the #7/8 but at times you may like a #5 or 6 as it will decrease the cleaning zone and look nicer.  For stainless you want as big a cup as you can get away with practically speaking.

Gas lenses are a great option and the only downside I can think of is that they're larger in diameter...not always an issue.  Pyrex cups are fantastic in that not only can you see through them, but they also seem to reflect the arc light right back on the puddle so you can see better even when you're not looking through them.  The downside to pyrex cups is that they can't handle as much heat as alumina cups (pink type), they're a bit more fragile and they cost a lot more.

I use alumina cups on gas lenses for the majority of my welding, but switch to the pyrex when they offer an advantage....a great option to have.


----------



## 7milesup (Jun 21, 2021)

Excellent points G-Man.


----------



## General Zod (Jun 21, 2021)

cathead said:


> I have both 3/32 and 1/8 tungstens.  Is there anything wrong with using the 1/8 for lighter work as long as I use the appropriately sized cup
> for the job?



Nothing wrong with it, but some machines have limited hot-start settings that will make arc initiation more difficult, even with a long, sharp taper.  So I'd say it's quite  machine-dependent.

Another downside of a gas-lens set-up is if you have an inadvertent draft, or shielding gas problem, even for a split second the molten pool can become so agitated with the presence of oxygen that it will spit up molten droplets of steel and it will instantly stick to and clog up your mesh screens on the gas lens.  Which usually means it is ruined and is typically discarded.  With a standard collet body set-up, the same is not always true.


----------



## GunsOfNavarone (Jun 22, 2021)

At the end of the day, everyone bends the rules to get the job done. Long stick out is nice and it requires more gas. I hate buying argon, it’s expensive. I’m getting ready to buy a 376 cf tank so I just have to pay for gas going forward….not the tank as well.
Here’s my 9 torch but can flip flop to a 17 as well (series 2 or 3) I normally run 1/2 to 5/8” stick out on it….some people go by cup size and limit stick out that way..
Here’s some of my Furick Jazzy, FUPA, Edge LF, good old ceramic on a 1/16” tungsten…


----------

