Gas lens?

One thing to note is that you really don't need to get different sized collet bodies. A .040" or 1/16" collet will fit and work just fine in a 3/32" body.

Quote:

---

Originally Posted by sportbike

One thing to note is that you really don't need to get different sized collet bodies. A .040" or 1/16" collet will fit and work just fine in a 3/32" body.

---

I drill gas lenses to a larger size sometimes but the collets don't interchange... or are you saying that an .040" or 1/16" tungsten and collet will work in a 3/32" body.

FWIW...my experimentation has told me that, at least for a 17/18/26 type torch with the gas lens collet body, the largest diameter full length cup (which would be, only the #8 cup) allows better and more reliable gas coverage than the "stubby" cup #12. The results may vary depending on which gas lens collet body you are using. But generally, the OD of the "mesh" diffuser screen matches the ID of the #8 cup. If you use a "stubby" #12 cup, the gas flow coming out through the mesh diffuser seems to (with some different gas lens collet bodies more than others...) encounter turbulence and screw up the gas coverage. You may find you have no better gas coverage, or even worse gas coverage with the "stubby" #12 cup than with the #8, despite the fact that the #12 is much larger ID. Getting good coverage is about more than just the cup ID... you want to keep the gas flow from going turbulent as well.

CK Worldwide's proprietary brand of the "gas saver" diffusers are a little different, however, because they extend all the way to the inside diameter of the cup at the cup's widest portion. So you could use a "straight walled" cup on one of those, potentially also very short in length if desired, without the gasflow going turbulent.

But just as a general rule I would say, with a gas lens collet body, if you want the widest gas coverage, go with a cup with an ID that matches the OD of the mesh diffuser. Just my 2c.

PS - there are definitely situations where I would avoid using a gas lens. Any welding on "dirty" materials, such as rusty panels, zinc, etc that could "split" or spatter out junk like molten metal back at the torch when welding it, can quickly ruin a gas lens diffuser. I install a standard collet body (non-gas lens) for that type of welding, which are pretty much spatter resistant.

With the #12 you need to use some kind of diffuser. A stainless screen, chore boy, or a scotch brite pad. I like to screen the best but all of them suck when you are putting in the tungsten you have to be careful it doesn't move.

Quote:

---

Originally Posted by zoama585

I drill gas lenses to a larger size sometimes but the collets don't interchange... or are you saying that an .040" or 1/16" tungsten and collet will work in a 3/32" body.

---

I was referring to using smaller collets in the 3/32 body. No need to spend the extra money to get teh smaller bodies. I'm not even sure why they make all of the different body sizes. :confused:

Quote:

---

Originally Posted by sportbike

I was referring to using smaller collets in the 3/32 body. No need to spend the extra money to get teh smaller bodies. I'm not even sure why they make all of the different body sizes. :confused:

---

With a tungsten that matches the collet, correct ? I don't mean to be aggravating, I just wanted the info to be clear for everyone who reads the thread.

Quote:

---

Originally Posted by rab

yeah some pics would be great.

---

I posted a picture of the 9/20 torch large gas lens and one with all of the 9/20 setups for reference. (standard set up, small gas lens and large gas lens)

http://i854.photobucket.com/albums/a...Gaslens20L.jpg
http://i854.photobucket.com/albums/a...rp/20torch.jpg

At one of the local trade schools here, I noticed that all their TIG equipment had gas lenses installed - standard issue for the TIG welding students. It was likely because of the volume of welding that happens in a school as well - one class with 20 welders going at it all day can consume a lot of gas, so if you can reduce the flow a bit, it can really add up. The welding is usually pretty clean as well, since they are focused on technique first, especially for new students.

Cheers,

Mike

Quote:

---

Originally Posted by jakeru

FWIW...my experimentation has told me that, at least for a 17/18/26 type torch with the gas lens collet body, the largest diameter full length cup (which would be, only the #8 cup) allows better and more reliable gas coverage than the "stubby" cup #12. The results may vary depending on which gas lens collet body you are using. But generally, the OD of the "mesh" diffuser screen matches the ID of the #8 cup. If you use a "stubby" #12 cup, the gas flow coming out through the mesh diffuser seems to (with some different gas lens collet bodies more than others...) encounter turbulence and screw up the gas coverage. You may find you have no better gas coverage, or even worse gas coverage with the "stubby" #12 cup than with the #8, despite the fact that the #12 is much larger ID. Getting good coverage is about more than just the cup ID... you want to keep the gas flow from going turbulent as well.

CK Worldwide's proprietary brand of the "gas saver" diffusers are a little different, however, because they extend all the way to the inside diameter of the cup at the cup's widest portion. So you could use a "straight walled" cup on one of those, potentially also very short in length if desired, without the gasflow going turbulent.

But just as a general rule I would say, with a gas lens collet body, if you want the widest gas coverage, go with a cup with an ID that matches the OD of the mesh diffuser. Just my 2c.

PS - there are definitely situations where I would avoid using a gas lens. Any welding on "dirty" materials, such as rusty panels, zinc, etc that could "split" or spatter out junk like molten metal back at the torch when welding it, can quickly ruin a gas lens diffuser. I install a standard collet body (non-gas lens) for that type of welding, which are pretty much spatter resistant.

---

The screen on the large collet body (.7540) is almost as large as a #12 cup (.76) and is smaller than a #short. The ID of the large gas lens is (.8180). The #8 cup is only (.5).

The large flood cups will not really save any on gas, but will give a lot better gas coverage. I use them on titanium (#short cup) and they do work good.