Gas Lenses

[AAA]

Guys,

Posted this on another forum but didn't get a lot of response.

tell me all you know about gas lenses! I've never used one, but lots of others sware by them. Seems to be one of those mystical things.
If I need to stick the tungsten out I'd usually just turn up the argon flow. I see lots of folks doing titanium and stainless using them.
For titanium and such I use a small container with a separate argon supply to weld inside of if it's a small part. What's the advantage of using a gas lense in a purge tank?
They reduce the amount of argon used, right? Heard it mention that I could cut the gas flow in half. This sounds good to me, argon ain't cheap, so if I can save a few $ it sounds good to me.
Should I get the small sized ones or large sized ones?
Any advantage to a pirex cup over a standard one?
Is there any advantage to using them on Aluminum?
Any other reason for using a gas lens over a standard cup.

Any info appreciated.

Thanks

Mike

[tigman]

I use one at work on aluminum,I find it gives me cleaner welds.The gas lense allows me to run lower pressure by straightening out the gas flow and it will allow you to stick out the tungsten up to 6 times the dia in a draft free work area.Scott