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Gas lens no good?

Posted: Sat Mar 03, 2018 2:23 am
by DAMINK
Hey all.
I purchased a "cheap" online gas lens kit as below.

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Seems like an ok unit? Well every time i try weld with it i get horrible welds.
Green flame, sparks and a wandering arc.

Here is an example. Please dont hate me for i can not weld worth a shit!! :lol: But i do enjoy trying.

First off a few details im sure are going to be asked. Im Aussie so aussie measurements :)

Material is 1.5mm box section.
Tungsten is 2.4mm Thoriated.
Gas flow rate is around 6 LPM.
Filler rod is 1.6mm SS ER 347 (Yea i know, its the only filler i had at the time)
Amps started at 40 and raised to 50.
Beers had.... 4 but very nice beers so its ok.

First off im doing a weld with a standard setup, no gas lens. Again dont hate me for my welds are shit.

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Weld on left was 40 amps, one on right was 48 amps.

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Welds look grey as ALWAYS! Dunno whats up there sorry...... No shoes DAMN thats obvious!

Next setup is the gas lens.

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Cleaned up the other welds and tried to put down a couple with this damn lens.
Got porosity and all sorts of weird goings on.
Gas lens no good or operator no good?

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Here it is all cleaned up.........

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So all the other welds apart from the first 2 are with the gas lens.
I know all welds are bad, but i think you will notice the gas ones are worse.
I did try increase the flow rate to about 15 lpm which is a HUGE amount. Thats the top weld and come out better than others but still sparked a lot and green.

Any advice for this novice appreciated.

Re: Gas lens no good?

Posted: Sat Mar 03, 2018 2:33 am
by tweake
what tig torch do you have ?

Re: Gas lens no good?

Posted: Sat Mar 03, 2018 3:34 am
by DAMINK
tweake wrote:what tig torch do you have ?
I am running an air cooled #17 No pedal, just the switch.

Re: Gas lens no good?

Posted: Sat Mar 03, 2018 4:23 am
by noddybrian
I don't think it's you ! - your welds may not be god level yet but you got the idea fine so just more seat time will improve this - the difference between gas lens & regular certainly looks gas coverage issue - I don't use pyrex myself but what stands out is the low cost pyrex cup is parallel so the opening is noticeably larger than the diameter of diffuser screen - with ceramic cups that does'nt work well which is the main reason to switch up to a large lens instead of regular if going above around a N0.8 cup - I'm guessing that is around a #10 - I cannot explain the effect but I think it's just too big a cup for the screen size - the expensive pyrex cups tend to have a step in them ( or a secondary screen part way down )- as the gas lens is still threaded try screwing on a regular alumina cup no bigger than the screen - say a 7 or 8 & try welding - my guess it will work fine as unless the mesh is blocked badly from splatter gas should come out where it should - provided there are no air leak paths causing gas contamination.

Re: Gas lens no good?

Posted: Sat Mar 03, 2018 4:36 am
by tweake
not sure on the cup thing.
i think its more likely one of the o rings is in the wrong place and you either have a leak or its obstructing the inlet holes.

Re: Gas lens no good?

Posted: Sat Mar 03, 2018 8:04 am
by cj737
tweake wrote:not sure on the cup thing.
i think its more likely one of the o rings is in the wrong place and you either have a leak or its obstructing the inlet holes.
I am leaning this way too...

What all your welds show is too little amps, or too much filler. The "grey" in the first picture is because you're hovering too long to get the volume of filler to weld in, because you're adding too much filler for the heat you're using. Also, the ceramic cup you used, yields crap for gas coverage. Use a quality gas lens.

The double O-ring on your pyrex cup looks odd to me. The picture is out of focus, so its hard to be certain. Screw the lens in tightly to the torch first, then wet and slip an O-ring on the lens. Then press and twist the pyrex on. You should not need 2 O-rings :shock: I would install the pyrex on from the bottom to help keep the O-ring below threads. But make sure the O-ring is rather wet.

The other element is the material thickness. Such thin material only cleaned on 1 side, will suck goop through and from the back. Stainless wire doesn't appreciate that, nor does mild steel wire.

Lastly, arc length. You should be "almost" touching the puddle to get good welds. If the gap is more than the filler rod diameter, you're too far away.

Re: Gas lens no good?

Posted: Sat Mar 03, 2018 5:52 pm
by DAMINK
Thankyou for your help guys.
I decided to do a couple of tests last night. First i simply blew air through my normal setup then the gas lens.
Gas lens felt very restricted compared to the standard setup i had.
So i decided to cut one open and see whats up with them. Rough cutting has made it a little hard to see sorry.

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It appears the gas runs from the torch into the top of the gas lens then out of 4 little holes and through the screen.
Those 4 holes are very tight and close to the outer body, which is why i assume i had restriction.
The screen is very tiny also. Far smaller than the cup as mentioned above. Seems very problematic right off the bat.

I think the correct thing to do now is first of all practice my welds..(heat, travel speed and arc length)
But secondly and more importantly i need to bite the bullet and buy a "Good" gas lens setup.
Any suggestions for a supplier over this side of the world?

Re: Gas lens no good?

Posted: Sat Mar 03, 2018 7:02 pm
by tweake
DAMINK wrote: Any suggestions for a supplier over this side of the world?
either
https://weldmongerstore.com/collections/kits ;)
or BOC

Re: Gas lens no good?

Posted: Sat Mar 03, 2018 7:17 pm
by DAMINK
Its a little hard to justify shipping unfortunately, however i may just bite the bullet. I trust Jodies products no question.
He is a legend and i expect he would never put his name to something apart from quality.

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Thats from BOC and looks very much the same as the ones i am using now.
Hmmmmm if BOC sells them they must work right? I mean BOC is a credible company.
Perhaps i am missing something here, will go into shed and lay down some beads and see if i cant get these damn things to work as they are supposed to.

Re: Gas lens no good?

Posted: Sat Mar 03, 2018 8:30 pm
by cj737
It is my opinion and experience that while the CK lenses are good, the Miller brand are actually better. The surface area of the lens is larger, the collet/tungsten hole has a smaller wall dimension, and they have a dedicated O-ring groove for using Pyrex cups.

Re: Gas lens no good?

Posted: Mon Mar 05, 2018 9:36 pm
by OzFlo
DAMINK wrote:Its a little hard to justify shipping unfortunately, however i may just bite the bullet. I trust Jodies products no question.
He is a legend and i expect he would never put his name to something apart from quality.

Image

Thats from BOC and looks very much the same as the ones i am using now.
Hmmmmm if BOC sells them they must work right? I mean BOC is a credible company.
Perhaps i am missing something here, will go into shed and lay down some beads and see if i cant get these damn things to work as they are supposed to.
G'day mate..

The BOC ones work just fine and I am using them currently. Where are you located?

Re: Gas lens no good?

Posted: Fri Mar 16, 2018 6:39 pm
by Troy Boy 72
Hey mate , Some of the gas lenses you see in BOC stores are CK gas lenses just rebranded with the BOC name . If you ring them and have trouble finding someone that knows anything about CK products which I'm guessing you will then ask to speak with a Jamie Natoli or email him on Jamie.Natoli@boc.com and ask him to ring you . Just sent you a PM as well.
Hope this helps
Cheers Troy

Re: Gas lens no good?

Posted: Sat Mar 24, 2018 12:12 pm
by Oscar
I wonder just how bad these are. Anyone care to send me one of these crappy ones so I could try out? I'll pay shipping.