[FireKracker50]

I purchased a gas lens kit from here:
http://www.ebay.com/itm/222441643752?_t ... EBIDX%3AIT


I have not been impressed. I have tried from 12-25cfh of argon and do not feel i am getting good gas coverage.
If i extend the tungsten more than 1/16" past the end of the pyrex cup then its unusable even for mild steel.
I usually use about 1/4" with 12cfh but I can get at least 3/4" of stickout from a standard #6 cup with no gas lens with 18cfh.
I would think with this #10 cup and gas lens i could get over an inch of stickout.
Does anyone have any thoughts as to why this isn't performing for me? Or things i could do to get better performance from it?

I feel like the gas lens is a small diameter compared to others i have seen. Also it ends well before the end of the pyrex cup. Am i supposed to add a metal screen or something as a diffuser. It doesn't show one in the picture and it didn't come with one.

[weldin mike 27]

You need a wider cup to extend that far. Sometimes known as a champagne glass cup

[AndersK]

How many layers of mesh do they have ?
Should be at least 3-4 to give good distribution.

It looks like the mesh don't have contact with the body all way around. That will disturb flow and might cause air to be pulled in.

[GreinTime]

You are running double o-rings under the cup right?

Sent from my VS995 using Tapatalk

[kiwi2wheels]

error

[kiwi2wheels]

Don't waste money buying anything other than reputable name brand gas lens for any torch.

Remember the saying; " life was like a box of chocolates. You never know what you're gonna get."

100% applicable in this instance.

[MarkL]

A set like that from most places would cost at least $150, probably more like $200. My pyrex cups cost $20 each if I buy them singly from usaweld.com. So when I see a whole set like that for $18, it does not seem likely that it is made very well. Can you hear or feel gas coming out of the lens when you bump the foot pedal?

[cj737]

It is most likely a "setup" issue. Gas lenses use slightly different insulators, and Pyrex cups use O-rings to seal them against the gas lens.

You should definitely feel gas flowing onto your cheek when pressing the pedal. If not, its leaking out the back cap, around the insulator, or before the lens. Can you post a picture of your torch with this configured? Probably simple enough to see the issue.

With a #10, you should be able to get the stick out you need, but you will need more CFH than 18 in my opinion. Probably closer to 25CFH from my experience.

[exnailpounder]

Like anything else in life...you get what you pay for. There is no way those cups are Pyrex. They can't be borosilicate glass for that price. I am betting if you ever get that set up welding, those cups will shatter pretty quickly. IMO clear cups are like fishing lures...designed to catch fisherman...not fish. After all, you're supposed to be watching your puddle instead of torch guts. There's alot to be said for good old pink alumina cups. Cheap too. My humble opinion.

[FireKracker50]

I didn't buy the set for the Pyrex cups. I could care less if they are clear or alumina cups.
I bought it because i wanted a stubby gas lens setup.
yes i hear and feel gas.
If you click on the picture i have attached in the upper right corner there is a picture of the torch setup. I installed mine exactly the way it is in that picture.
I used the insulator and o-rings provided.
I will snap some more pictures and attach.
There are no screens except for the one in the gas lens itself. and the gas lens is a smaller diameter than the Pyrex cup.
I feel like the problem is either with the gas lens itself or the fact that it ends way before the end of the cup and isnt as big in diameter as the cup.

[cj737]

There are no screens except for the one in the gas lens itself. and the gas lens is a smaller diameter than the Pyrex cup.

This is correct within certain tolerances. The cup obviously has to be wider to pass over the lens, but the O-ring seals it. Is your cup firmly secured by the included O-ring?

I feel like the problem is either with the gas lens itself or the fact that it ends way before the end of the cup and isnt as big in diameter as the cup.

Again, the lens will be shorter than the cup. How much differs by which cup you use. The #10 cup is designed for coverage, and the gas exiting the lens will be stabilized (at least in theory) by the gas lens. So it being shorter shouldn't be the issue. I'd run a test by cranking up the CFH and see if that helps/resolves it.

Do you happen to have a stubby #7 Alumina that you could thread on for a side-by-side to determine cup or lens as the issue?

By the way, I like Pyrex cups too. I use a #8 a LOT!

[MarkL]

... and the gas lens is a smaller diameter than the Pyrex cup.
I feel like the problem is either with the gas lens itself or the fact that it ends way before the end of the cup and isnt as big in diameter as the cup.

The mesh screen on my gas lens is slightly larger in diameter than the inside of the cup. So when I slide the cup on, I push it on slowly so it deflects the screen slightly and makes it the shape of a shallow dish. As an example, if you look at this photo of a Furick cup, you can see how the screen is dish shaped to keep it in tight contact with the inside of the cup.

[FireKracker50]

I do not have any Alumina cups for the gas lens.
Yes the lens is secured by the orings.
Here is the standard setup i use.

Here is the gas lens setup





I just grabbed some old scrap pieces out of the garage and did a few quick examples to show.
Areas in black are welded with gas lens, areas in green are with standard setup.

[Oni]

In my experience off brand gas lenses are very hit or miss, more miss than anything. Try a new gas lens from CK or Jody. For $18 at least you got a couple of back caps and other consumables.

[MarkL]

OK, I see what you have, I was not paying attention to your first photos. So it seems like either the lens body is not allowing a sufficient amount of gas to pass, or the gas is leaking somewhere else (like out the cap), or too much of the gas is flowing directly around the tungsten and not through the screen. You might put a bit of slightly soapy water around the seal on the cap to make sure it's not leaking.

[Oscar]

Thread the gas lens in all the way without anything else on the torch. Then look through the other side where the back cap would normally be so you can see if the gas lens collet body is blocking the shielding gas hole inside the torch head.

[exnailpounder]

Thread the gas lens in all the way without anything else on the torch. Then look through the other side where the back cap would normally be so you can see if the gas lens collet body is blocking the shielding gas hole inside the torch head.

The chinaman probably forgot to drill the hole on purpose... and still got paid. Hahaha..roundeye!

[FireKracker50]

I'll check that out. But I'm getting had flow I can hear and feel it coming out the cup. I'm thinking the gas lens itself is garbage. Or that too much gas is flowing around the tungsten. It's not a tight fit around tungsten.

[cj737]

Did your set come with all 4 lenses and collets? If so, swap to the 1/8 or 1/16 and see what results you get. I don't have the impression your welds are suffering from too little flow, or too much flow past the tungsten; rather the opposite.

[FireKracker50]

Yeah it came with all four. I'll try another size today.
If u don't think it's too low or too much past tungsten what do u think it is? Too turbulent flow?

[Superiorwelding]

Sorry you are having so many problems. Unfortunately, this is the name of the game with these extremely cheap, in many ways, gas lens kits. I quit using them all together. Spend the extra few dollars, and that is really all it is, on a quality name brand gas lens and you won't have these problems. Lesson learned for sure.

Also, one problem I ran into working on my Unbreakable TIG Cup™ was if the cup i.d. (at the exit) was larger than the gas lens itself your coverage is extremely poor. To use a larger cup than the gas lens you must have a secondary diffuser, as you see with all the large cups out there. If you wanted to make these cups work, and assuming the gas lens' themselves are "good" simply add a second diffuser and your coverage should improve.

Honestly though, we talked about this very problem in a podcast episode (don't remember which one) how these cheap kits just don't seem to work. Sure, one out of 100 might be fine but I feel you should learn on a regular collet body setup and when you master that move on to the more "exotic" stuff. Once you start to add all these variables in your learning you can quickly get frustrated and not know where to look for the problem. My opinion.
Jonathan

[Oscar]

Also, one problem I ran into working on my Unbreakable TIG Cup™ was if the cup i.d. (at the exit) was larger than the gas lens itself your coverage is extremely poor. To use a larger cup than the gas lens you must have a secondary diffuser, as you see with all the large cups out there. If you wanted to make these cups work, and assuming the gas lens' themselves are "good" simply add a second diffuser and your coverage should improve.
Jonathan

I agree 100%.

OP, if you notice, most "standard" gas lens, meaning medium-large that use regular pink alumina cups, all "stop" the cup size when the cup exit is the same size as the screen mesh (and even then, they still have a slight taper).

For example, if you are using a medium gas lens collet body on a 17/26 torch, I doubt you'll find many, if any at all, alumina cups that are larger than a #8. If you want an alumina cup larger than #8, you typically have to switch to a large diameter gas lens collet body.

If you are using a large diameter gas lens collet body, the largest you'll typically find is #12. If you look at the mesh screen on a large dia. gas lens collet body, turns out the mesh screen is about, yup you guessed it, 3/4"---the same size as the #12 cup exit orifice. The exception is the #15 cup. It doesn't really look like a cup, more like a thread on protector----it just covers the collet body and does not aid with maintaining laminar gas flow. I have one, and while it worked, the gas covered just wasn't what I felt "it should be" for that large of a "cup".



IMO, it's the same reason, the Furick FUPA cups have the mesh screen/diffuser in the first place----the tiny mesh on the gas lens collet body that it installs onto is simply not going to produce the laminar gas flow that is needed for good coverage.

I'd like to test my hypothesis with your gas lens, if you'd like. I still have some mesh screen left over from my experimentation, I can punch out some screens for you to try out. Just let me know what size tungstens you are using.

[motox]

Oscar the philanthropist, this really is a great forum!!!!!
craig

[FireKracker50]

I have from .040 up to 1/8th tungsten and gas lenses for this kit.
I have been using the 3/32" size thus far. I would like to know if a diffuser would remedy my troubles.
I am always experimenting with different things. I love to tinker.
I am an engineer by trade, angler by heart, and welder hobbyist.
I mainly learned to weld just to work on outboard motors as i enjoy building racing outboards. And because i break allot of stuff.

[Oscar]

I have from .040 up to 1/8th tungsten and gas lenses for this kit.
I have been using the 3/32" size thus far. I would like to know if a diffuser would remedy my troubles.
I am always experimenting with different things. I love to tinker.
I am an engineer by trade, angler by heart, and welder hobbyist.
I mainly learned to weld just to work on outboard motors as i enjoy building racing outboards. And because i break allot of stuff.

Great. Please take your favorite dial calipers and measure the ID of that clear nozzle, and I'll look for my mesh and punch out some screens maybe on Sunday or Monday. I'm not a philanthropist, I just like to make people aware that "I was right", LOL. And if I'm not, I just disappear for a good while so no one remembers, LOL.