[Shondave]

Hi to all Tig passionates and experts!

I tig weld on mild steel for hobby at home, trying to be more accurate than with the mig.

I usually tig with wp9f torch and stubby gas lens alumina cups with good results.

After watching tons of utub clips of Pyrex gas lenses, I recently purchased a jumbo champagne gas saver (on eBay from China).

I had the time to try it just once on mild steel and the results really disappointed me, even with a huge amount of argon (20lt/min. Approx 40cfh). The weld is nothing special, no real matters like dark tungsten or sparks but less performance than a pink gas lens.

Probably mild steel is not the best material to have nice colors, I will try with stainless as soon as I can.

Attached a picture of the part I am talking about.

Any suggestion or experience will be appreciated, thanks to everyone.

[Poland308]

From the looks of the pictures the gas screen in your lense only has one layer. That changes gas flow dynamics and by buying a cheaper cup you have likely sacrificed any benefit of the gas lense.

[Oscar]

I have the CK Worldwide version of that jumbo cup, and the 1 time I used it it worked great. Assuming everything is assembled correctly none of the parts are compromised (we don't know because we're not there to see you assemble the torch, nor did you show your actual parts in a picture), then it all boils down to technique and application to the specific joint geometry. Some joint geometries are complete opposites when it comes to gas coverage. You've said a lot, but really, you haven't told us anything about what you're doing and our guesses are as good as yours until you start disclosing actual information, IMO. For example, you did know that in the main picture you posted, the parts are assembled incorrectly (with the exception of the small pic in the middle towards the top), right?? If you assembled it like in the main larger picture, you have it wrong, but since we can't see because we don't have pictures, no one knows.

[Shondave]

The screen is made of two very thin and thick net mesh compressed between two perforated disks of metal (the one you see n pic) actually is accurately made with no gaps.

On web videos someone is using this part with nice results but they don't specify settings.

[tweake]

the pic shows it incorrectly assembles wit the spacer inside the cup. pic top centre has it right.

but frankly theres always threads on issues with cheap gear.
imho its not worth cheeping out on. especially for us hobby guys we simply do not go through enough gear to worry about cost.

[LtBadd]

Probably mild steel is not the best material to have nice colors, I will try with stainless as soon as I can.

I think your right, can you post a pic of what you welded?

Also how did you prep the steel for welding?

[Poland308]

If your gas diffuser looks like the one in the photo, then it’s not a screen. It’s just a single layer of perforated metal. That’s not a gas lense. The purpose of multiple layers of screens in a gas lense cup is to break up the laminar flow of gas. By Causing turbulence with multiple screens you get an even flow of gas coverage. Laminar flow like you get with the holes in perforated metal has a tendency to draw air in (edit) Air in a ) siphon fashion along each gas stream.

I digress. Stuff a thin layer of steel wool on the leaving side of the perforated metal disk. This should get rid of your gas issues. Don’t believe just try the .50 cent fix.

[Oscar]

If your gas diffuser looks like the one in the photo, then it’s not a screen. It’s just a single layer of perforated metal. That’s not a gas lense. The purpose of multiple layers of screens in a gas lense cup is to break up the laminar flow of gas. By Causing turbulence with multiple screens you get an even flow of gas coverage. Laminar flow like you get with the holes in perforated metal has a tendency to draw air in (edit) Air in a ) siphon fashion along each gas stream.

I digress. Stuff a thin layer of steel wool on the leaving side of the perforated metal disk. This should get rid of your gas issues. Don’t believe just try the .50 cent fix.

It has a very fine mesh between the layers of perforated sheet, at least the CK worldwide version does.

[Poland308]

If your gas diffuser looks like the one in the photo, then it’s not a screen. It’s just a single layer of perforated metal. That’s not a gas lense. The purpose of multiple layers of screens in a gas lense cup is to break up the laminar flow of gas. By Causing turbulence with multiple screens you get an even flow of gas coverage. Laminar flow like you get with the holes in perforated metal has a tendency to draw air in (edit) Air in a ) siphon fashion along each gas stream.

I digress. Stuff a thin layer of steel wool on the leaving side of the perforated metal disk. This should get rid of your gas issues. Don’t believe just try the .50 cent fix.

It has a very fine mesh between the layers of perforated sheet, at least the CK worldwide version does.

Correct
The one in the picture does not!

[Shondave]

Thanks for the replies,

Today I couldn't weld but I gave a better look at the part.

The picture I posted is from one of the eBay sellers and it is of course wrong, that is the way they put everything together in the package.

I mounted properly, don't worry, and between the two perforated metal there are two compressed layers of fine mesh.

The problem in my opinion is that the perforated sheets are not specular and are also pinched in a way that a lot of holes become closed, so the gas has very little space to flow, I will try to disassemble it and try to let the holes match as much as possible.

[Oscar]

Thanks for the replies,

Today I couldn't weld but I gave a better look at the part.

The picture I posted is from one of the eBay sellers and it is of course wrong, that is the way they put everything together in the package.

I mounted properly, don't worry, and between the two perforated metal there are two compressed layers of fine mesh.

The problem in my opinion is that the perforated sheets are not specular and are also pinched in a way that a lot of holes become closed, so the gas has very little space to flow, I will try to disassemble it and try to let the holes match as much as possible.

Gas molecules are smaller than any mis-alignments. So long as there are no gaping holes on the perimeter, gas will still flow, and the mesh will still cause it to flow laminar, more so than if they were not there. Regular gas lens collet bodies are the same way. There are multiple screens stacked right on top of each other with no consideration for orientation of the holes, and they typically work just fine (excellent, actually).

[Poland308]

Thanks for the replies,

Gas molecules are smaller than any mis-alignments. So long as there are no gaping holes on the perimeter, gas will still flow, and the mesh will still cause it to flow laminar, more so than if they were not there. Regular gas lens collet bodies are the same way. There are multiple screens stacked right on top of each other with no consideration for orientation of the holes, and they typically work just fine (excellent, actually).

Yup!