[WJH]

I've been enjoying my stock size 17 torch, able to do what I needed with it. Recently I purchased a stubby gas lens kit for it, and discovered that I need to re-learn how to tig weld. First thing I noticed was that the same regulator setting was causing the arc to be "blown" for a lack of a better term, my Tungsten no longer staying as clean, and the weld puddle to be much wider, along with the arc. The cup size is a #8 on the stubby kit, much wider than the stock cup with the stock 17 style setup.
I turned down the gas regulator, and fixed the arc issue, but now my work piece is covered in brown oxidation. I suppose I need to turn up the post flow to fix that? Also, how much electrode stickout should there be? I am tempted to go back to the stock setup

[Welder kurt]

I very seldom use anything but a gas lense unless I'm working on aluminum then I go back to a regular cup. On my my 280DX I normally switch between a number 6 and 7 gas cup depending on what material I'm working with, and my stick out is always just enough to see and get into what ever joint. I usually run my argon around 12 to 15 cfh, if your getting oxidation after you complete your weld I would say turn up your post flow a bit

[MosquitoMoto]

Very odd, WJH.

as a noob (still am) I welded with a conventional collet body for a couple weeks, then switched to a gas lens. Overall, better, smoother arc, and eventually I turned my gas flow down just a tad, too. Is your lens good and clean?


Kym

[WJH]

Very odd, WJH.

as a noob (still am) I welded with a conventional collet body for a couple weeks, then switched to a gas lens. Overall, better, smoother arc, and eventually I turned my gas flow down just a tad, too. Is your lens good and clean?


Kym

Brand new, USA made. I only had a few minutes to play with it before I had to travel back to work. Will admit the test piece was not cleaned. Will try again when I get home, next time prepping the material properly, and regrinding the tungsten. Using the red tipped tungsten. Want to try some 2% Lanthanated at some point.

[MosquitoMoto]

Okay.

Hope the experience improves with use. My gas lens just improved everything by, oh, 10 percent or so, it seemed to me. I'll admit that I'm so new to this that maybe some of it is psychosomatic, but the one thing I'm sure of is that those odd times when I used to get a brief flare up or pop, even holding great angle and arc length, have gone with the lens. I am confident that the better and more stable gas coverage has helped.

Let us know how you go...very interested to hear how things unfold with more seat time.



Kym

[Otto Nobedder]

Typical stick-out on a gas lens should not exceed 6X the tungsten diameter (3/4" for a 1/8" tungsten, or 9/16" for a 3/32), though it often has to. Pay attention to your torch angle, as well. The laminar flow from a gas lens can actually increase the air draw behind the weld if you get too steep and aren't moving fast enough.

I have more I can say on this, torch angle in particular, but let's get you making clean, well-colored welds first to rule out other issues.

Steve S

[zank]

Sometimes you do whatcha gotta do

[Welder2008]

Make sure you're using the proper neoprene "washer" behind the ceramic cup. Sounds like you're getting atmospheric gases pulled in.

[WJH]

None of my welds with cold rolled 1018 ever have had the pretty colors. Always a dull gray. I am on the road right now, won't be until Tuesday that I get to try to play with it again. My tig cup has no Neoprene washer, just that white plastic heat sheild

[Markus]

Make sure you're using the proper neoprene "washer" behind the ceramic cup. Sounds like you're getting atmospheric gases pulled in.

Yup thought so too. Check leaks from your torch. With gas lens you should not have any problems at all, specially if you have setted the amount of argon flow right.

I recommend to do a little test with clean stainless steel. Steel can be used also.

9-mnZ2oyCxM

[WJH]

Clearly something is leaking. I know for a fact that my feed line has a very slow leak, but I doubt it would cause my discolor.
In the mean time however, here is my build log for the locomotive I am building. The pictures show some fusion tack welds I did with my stock 17 setup, and also some crappy bead laying to fix a machining error. You can see the color I get.
http://www.ge44.org/index.php/2015/09/0 ... izer-bars/
The locomotive is going to have a lot of tig welding done to it.

[Welder2008]

If your line has a small leak, depending on what you consider small, it could leak when the system has pressure built up in it but when you are welding and the gas is flowing, you could be creating a draft sucking in outside air.... The neoprene washer I spoke of is exactly that, the white insulator between the back of the ceramic cup and the head of the torch. With a 17 style torch, depending on cup size, there could be 2 insulators rather than just one.

[Oscar]

I'm pretty sure most insulators are Teflon, not neoprene, unless that's a different name for the same thing.

[AndersK]

Youre right Oscar. Neoprene is synthethic rubber, CR. Teflon is PTFE.

[Markus]

Clearly something is leaking. I know for a fact that my feed line has a very slow leak, but I doubt it would cause my discolor.
In the mean time however, here is my build log for the locomotive I am building. The pictures show some fusion tack welds I did with my stock 17 setup, and also some crappy bead laying to fix a machining error. You can see the color I get.
http://www.ge44.org/index.php/2015/09/0 ... izer-bars/
The locomotive is going to have a lot of tig welding done to it.

You don't want to have any leaks in your system. Oxygen will slowly go trough any hose due to diffusion. No matter if there is pressure or not. So that in mind you have to have leak free connections.

I suppose you have cleaned the parts before welding. Mill scale and cutting oils will affect to welding a lot.

Your welds really look like there is oxygen or dirt in the puddle. Remember that cutting oils etc contains oxygen and also moisture.

Also did you weld agains the table. From the picture it seems that table's coating (zink or whatever) have been burned off and it went right in the weld!!

[WJH]

I did not clean the pieces before welding. The zinc coating on the table, that was from when I first got the table and welder, and discovered quickly my error. I welded the pieces on top of a 1" thick aluminum block. In the photo, they were placed for a quick photo after the fact.

[Otto Nobedder]

While this does not make sense to most people at first, a leak in your gas line anywhere between the flow-meter and the torch (actually, anywhere before the arc, like a broken o-ring on the back-cap or the Teflon gasket already mentioned, will draw air in when welding, rather than leak gas out.

You have a very slight positive STATIC pressure in the line, because of drag/resistance to gas movement. However, you have a fairly strong negative DYNAMIC pressure due to the flowing gas. Dynamic pressure is powerful enough to lift a 747 off the ground, and will definitely suck air in to your gas line.

The gas lens will magnify this problem a bit, because it flows gas better than the standard collet, further reducing that slight positive static pressure in the line.

I'd fix the known leak, then check the back-cap o-ring on the torch, and make sure the Teflon gasket(s) are in the right orientation and tight between the cup and torch. Take the tungsten out, put your thumb over the cup, pressure up the line a bit, and soap-bubble test everything from the flow-meter to the head of the torch, and I'm guessing you're going to find something leaking in the circuit. If you have the machine controlling the gas (rather than a valved torch), there can even be a leak inside the machine in the solenoid path.

Steve S

[Otto Nobedder]

I'll add one other thing, though it's quite unlikely.

I once chased a "leak" for an hour over bad color and odd behavior (bubbling in the weld on SS) only to discover my tungsten had been contaminated... Apparently three sharpened tungstens caught overspray from WD-40 while sitting in queue on top of my machine. I put in a fresh one right from the pack, and it welded fine. I later cleaned the contaminated ones with MEK, if I recall.

Steve S

[WJH]

Hello, I went home after the last trip and did a couple of things. First thing I did was install a higher quality potentiometer in the foot pedal, and tweaked it so the lowest point it turns on, gas is flowing, to protect the tungsten, and I stopped using the stubby cap on my torch. Turns out, the collet couldn't be engaged by the stubby cap because the brass threaded portion was machined too short, keeping the collet from tightening properly. I had the collet in backwards before to make it work, sort of.
I will machine a little spacer that will fix the issue, but the standard length cap has no such problem.
After making these two tweaks, the gas lens works MUCH nicer, keeping the electrode nice and clean, and my welds looking cleaner. Still haven't tracked down any more leaks.
I will say this however... My welder uses the barbs and hose clamps, would rather have a better setup than that.

[rick9345]

I like this style of clamp.
http://www.sealfast.com/f_oetiker_1ear.html

lots of OEMs use this motorcycles/cars

[kiwi2wheels]

To add to Rick's post, with the amounted of imported hoses and barbed fittings ( at least in Europe ) , the sizes of which don't seem to conform to any known norm..... I've found this version of the single ear also works well .

http://normapacific.com/Listing/Product ... ert+Clamps

[rick9345]

good
http://www.sealfast.com/f_oetiker_1ear.html



"Better"

To add to Rick's post, with the amounted of imported hoses and barbed fittings ( at least in Europe ) , the sizes of which don't seem to conform to any known norm..... I've found this version of the single ear also works well .

http://normapacific.com/Listing/Product ... ert+Clamps

[WJH]

Gentleman, I am happy with my gas lens and welder, thanks for the help. I just did this fusion weld, no real prep has been done other than a fresh bandsaw cut. My electrode is staying shiny, and now I am getting colors!

fusionWeld.jpg (70.03 KiB) Viewed 1857 times

[rick9345]

getting there

[WJH]

getting there

What should I look for to improve upon? Straighter beads, better taper off at the end?