Anyone using a gas lens?

[HemiRod23]

Noob here. Just got my PowerPro 256, and this is my first post.

I've been reading about gas lenses for TIG torch, and how they supposedly reduce Argon usage and improve shielding. Does anyone here use one? They're a little pricey, but it would seem you would save your money back in gas savings if they work. Just curious.

[Rambozo]

Depending on the size and the kind of welding you are doing, they can use a little more or less than a standard collet body setup. What they really do best is to provide better shielding out farther from the cup. So you can use more stickout with your tungsten. Also they can provide a larger shielded area for materials that need more shielding when cooling. This often comes at the expense of greater gas consumption. One downside is that they are larger in diameter so they can make the torch a little more bulky in very tight areas. They have their place along with a lot of other options. For some materials they are a must, while others not so big a deal. I tend to use them with mostly larger cup sizes, but not so much with smaller ones.

[undercut]

I'm mostly curious about the effect of the lens with smaller cups. I can see the laminar flow being conserved when the cup neither widens nor narrows the entire distance to the bottom of the cup but would the lens help at all for cup sizes smaller than 6?

[Rambozo]

I'm never running much stickout with small cups and have never had much of a shielding issue with small cups on steel. That's about the only use for real small cups anyway and I want the reduced bulk of a standard setup. Same with silicone bronze, another place for a small cup. With more reactive metals like stainless or aluminum you need more gas coverage anyway, so bigger cups are the rule. CK makes a gas saver system that is sort of a cross between a gas lens and a regular setup, but everything is different, the cups are push on instead of threaded, and I have never used them. Some people like them, but a lot of people say they don't work well. If you keep everything close and keep the breezes away, you can get away with pretty low flowrates for argon anyway. Every job is different, and more flow is not always the answer to shielding issues. Too much flow can cause the stream to suck in air from irregularities at the cup edge, too. If I did the same kind of welding all the time, I might be able to reduce gas consumption with the exact torch setup best suited to that job. For production welding I'm sure there are savings to be had. But it seems like I am always changing things, so I just try to do the best I can with the least gas required. I usually make a pretty good estimation and if things are going ok, I don't go back and try reducing the gas flow until I see problems. One thing that does make a difference is to dial in enough preflow or manually purge the line so that you don't try to start an arc with a big blast of argon going. I know there are small diameter line kits to overcome that issue and again they are said to save gas in production environments. From using welders without preflow, I sorta have the habit to tap the pedal so that the postflow is going before moving the torch into position and starting the arc.

[undercut]

Thanks, Rambozo. Super informative and relevant post for what I want to do. I'm living a bit vicariously at the moment but hope to have some argon soon and putting what I've read to practice - not that I'll be doing a lot of TIG'ing. I'll be doing the majority of my work with mild steel so I'll try using a standard small cup and work hard to minimize any breezes to start. The standard small cup should reduce my need for stickout too.