Hi, I just purchased a Tweco Black Gold WP 17 torch and it came with regular 1/16 and 3/32" colletts, not the gas lens style. I will mainly be welding aluminum, possibly some light gauge steel and maybe some stainless if it comes my way. What is the story with gas lens colletts? I see that Jody says they are required for stainless, but what's the theory behind using them? Will it help for aluminum? When using the gas lens, is a different cup required?
Any help is appreciated.
Thanks
Dave
Polaris_Dave
- Polaris_Dave
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you will be perfectly fine without one.
i use a #8 non-gas lens cup when welding aluminum at 15cfh flow and i have no issues at all
gas lens are used for greater coverage of argon. good if you need to extend your tungsten out an inch+ (you need a very big cup obviously) like what i do for exhaust manifolds.
once you get more practice you will see why you need to extend your tungsten sometimes etc... also a gas lense cools the puddle for aluminum which makes it more tricky to weld aluminum with a lense...less efficient power wise
i use a #8 non-gas lens cup when welding aluminum at 15cfh flow and i have no issues at all
gas lens are used for greater coverage of argon. good if you need to extend your tungsten out an inch+ (you need a very big cup obviously) like what i do for exhaust manifolds.
once you get more practice you will see why you need to extend your tungsten sometimes etc... also a gas lense cools the puddle for aluminum which makes it more tricky to weld aluminum with a lense...less efficient power wise
Polaris_Dave
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Thanks gurew!
Hey gurew... I was wondering how you figured that the gas lens cools the work more? In my experience, for the same cup size, I've found a gas lens needs a lower flow rate of shielding gas than a regular collet body. For example, through a #5 cup I might need 12 cfh with a regular collet body, but only 10 cfh with a gas lens collet body. I figured that the higher the cfh gas flow rate, the quicker the rate of work cooling. Would you agree with that or no?gurew wrote:a gas lense cools the puddle for aluminum which makes it more tricky to weld aluminum with a lense...less efficient power wise
I suppose if you are assuming that when switching to the gas lens you are increasing your cup width, and your cfh then I could see how it would cool the work more in that case.
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To the OP: for aluminum, I like a gas lens for those occasions where I need to stick out the electrode out by more than 1/2 the cup ID. With the gas lens, in a still-air environment, I try to keep the stickout to no more than 1 cup diameter. Most common aluminum weld joint I encounter where I need more than 1/2 cup width stickout (and so, need the gas lens...) is in a Tee joint type of fillet weld, where the work pieces obstruct the cup from getting in there close enough to the weld bead to shield the work with a standard collet body.
The fix is switching to the gas lens collet body, or alternately, I've been known to just reach for one of my funky, custom ground cups and "make do" with the standard collet body also. (especially this one: http://forum.weldingtipsandtricks.com/v ... 1296#p1296 ) I don't know if anyone else is doing that, but it does allow me to get the cup in there a lot closer, and get better shielding with less stick-out and maintain better gas coverage sometimes. It can be a hassle on some joints to have the rotation of the cup as another variable you need to control though.
But generally the thing I *don't* like the most about the gas lens #17 torch setup is how wide the diameter of the base of the cup is. The 1" thickness at the base of the gas lens cup (around the collet body) can get in the way with vision and reaching with filler rod on some cramped joints.