Large Diameter Gas Lens (CK 3 Series)

[jakeru]

I was at my local welding supply, swapping out an empty argon bottle and took a few minutes to look all around the place for anything else I may need. (Surprisingly... there is actually very little there anymore that I find myself still needing.)

Anyhow, digging through their TIG torch parts bins, I found a 3/32" large diameter gas lens collet body and #12 cup. They also had some "unknown part number" teflon insulator that looks like it went with it. The price was right on everything (the guy didn't even know what to charge for the teflon insulator; pictured below at upper-left), so I brought them all home. Here are all the parts pictured along with a "wedge" collet and some other teflon insulators I had kicking around, that might be able to make it work. (And I have accumulated one other style of large diameter gas lens teflon insulator before this as well; that one is shown pictured second from the left.)


Here is a close-up of the gas lens collet body. Interesting that it looks like the screen could be changed out (by removing the internal and external circlips).


The teflon insulator actually looks like it was designed for a "stubby" large diameter gas lens setup? (Tec Torch / Speedway sells these.) To be honest, it kind of has my scratching my head. Anyhow, I managed to cobble together some teflon insulators together and make it work, but it doesn't seem quite right. Maybe good enough at get going with.

.750" inside diameter should be able to keep the most finicky, oxidation prone materials well shielded, should the need arise.


By the way, here is a comparison with a #4 cup (.25" ID) to the #12 cup (.75" ID). As you can see from looking at the area of the cups, you can see the #12 cup is many more times larger in cross-section area than 4 ("12 divided by 4") times. Actually it is 9 times the cross sectional diameter. Therefore the #12 cup, to have the same average gas outlet velocity, needs 9 times the inert gas flowrate (cfh / lpm / etc.) You can't just scale up the flowrate linearly with the cup number, as the cross sectional area of the cup outlet increases exponentially with the cup size number / diameter. That's why you hear of people running HUGE flowrates on big cups (like 30-50 cfh).


Here is what the overall torch setup looks like with the large diameter gas lens, "ready to weld". I look forward to my next excuse to try it out!

(This is a "Trimline 210" 200 amp @ AC 100% duty cycle aircooled torch setup, with flexible neck, superflex hose, retrofitted torch switch, and custom cable sheath.)

[jdt1986]

I like it looks like you can get alot of gas coverage with that. Were are you located at? Wish my lws had a tig torch parts section; you have to ask them to get you what you want.

[jakeru]

I'm in the greater Seattle area. I guess as far as TIG welding specializations are concerned, we have some aerospace influences in the area (former Boeing headquarters, still manufacture some things here) as well as some Marine influences (having Puget Sound and other freshwater lakes and rivers, which means plenty of boats.)

You might ask at your local welding supply if it would be OK to browse the TIG torch parts bins; you never know what gems you might find (and the guy working the counter might not even know either!) When I found these parts I was interested in, the guy working the counter mentioned some of those TIG torch parts were older than ten years old, and he just seemed happy to get rid of some old inventory. Of course, it helps to build a relationship with the counter guy of sorts, so you can be trusted to browse through their parts bins. Also as a repeat customer, you can establish an "account" there and usually get some level of price reduction.