Bad bottle, again.

[toprecycler]

Originally Posted by Ironman

See this site.
If you cut or grind open a weld bead and you see worm holes in the bead, that's gas inclusion, and not from the shielding gas.

Just a quick screen shot in case the link goes dead sometime.




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[Oscar]

I see now. In most welding circles it is simply called porosity, which is why I did not recognize the terminology used here.

If only the gas cylinder was changed, it might be contaminated gas, assuming the conical sealing surface on the valve is not compromised, and assuming the regulator/flowmeter and/or it's hose was not damaged when removed from the old cylinder. There is also the torch. Maybe when it was set down, the sealing surfaces loosened up on the cup/insulator/back cap. Anything little thing that gets disturbed in TIG can also cause porosity. What I would do is check everything, even if it wasn't altered prior to the changing of the gas cylinder.

[Gadgeteer]

Originally Posted by Oscar

I see now. In most welding circles it is simply called porosity, which is why I did not recognize the terminology used here.

Sorry for the confusion of terms, Oscar. The term porosity didn't come to mind, because I'm not in most welding circles. In fact most of the time I'm out of the box, too.

[Shade Tree Welder]

Originally Posted by Gadgeteer

Hooked up when I got home and went back to railing project. Gas inclusion in beads, so I switched to aluminum. Hard to establish bead, carbon contamination, little to no etching along beads. When I attempt to introduce rod into the puddle the end of the rod, immediately, balls up, inside a glob of crud. Just junk. 2,000 psi, running at 10 to 20 CFH at torch. Only difference in setup was new bottle.

I've had several bottles with bad gas, but it didn't show up until pressure got to about 500 psi.

Does anyone have tips on a sure-fire way to test jugs for gas quality?

Originally Posted by arizonian

I'm confused. From steel to aluminum without changing anything but the bottle and filler mat'l?

I am really confused as well...

Same Tungsten, what tungsten are you using? Did you switch from DCEN on
steel to AC on aluminum?

What is your power source, air cooled or water cooled torch?

What does your tungsten look like?

Rarely are gasses bad, it is just a common excuse for other problems, when
you do have a bad cylinder, it is often water in the cylinder from hydrotesting
the cylinder. If the cylinder has been recently hydrotested you will see a
recent date stamp on the neck of the cylinder, they often get repainted at the
same time.

The other problem is sometimes they guys might refill a gas mixture like
90/10 into what is supposed to be pure Ar. Or something similar, this I have
heard of but again rare.

I use actual flow meters on my cylinders vs. gauges. Most of the cheaper
regulators use a high pressure gauge and a low pressure gauge that has been
calibrated for flow rate, based on flow through an orifice. The problem is if
you have a restriction in your torch you can show higher flow (in reality
pressure) but not have that actual flow at the torch.

If you are using an water cooled torch, you could have a small lead in your
torch head. I have a few times tore my torch down cleaned it really good,
reground my tungsten, made sure I had good laminar flow, etc. and without
seeing any obvious issues the problem was solved.

From what you have said, they 2 most likely issues you are dealing with
would be:

1. a contaminated tungsten, break off the end and regrind, especially if
you are switching back and forth between steel and aluminum.

2. shielding gas restriction between your supply and your torch.

[digger doug]

Originally Posted by Gadgeteer

Perhaps, you're easily confused.

Didn't think I'd have to draw a picture to help you understand my methods.

Originally Posted by Shade Tree Welder

I am really confused as well...

.

You too Shade ????
I was too, but seeing the OP' 'tude, I'm not wasting any more time trying to finger out what they are trying to explain, nor provide some help....

[mccutter]

Adding to what the others have said above:
You should have indicated you were using TIG, some were thinking MIG. That you mentioned using same gas for Al and Fe was the tip-off it was GTAW.
Knowing what your rig is would help. Power supply, torch, tungsten and size, etc.
Before I start an arc, I will tap the pedal to initiate gas flow and purge the line. I instinctively listen for the "hiss" of gas out of the torch. Lack of hiss will remind me I didn't turn the gas on. My meter is set at 20cfh, I use a gas lens on the torch and if a fan is blowing, I make sure it isn't blowing directly at me.

You pics look like you are running out of gas and/or torch is getting hot.

[Shade Tree Welder]

Originally Posted by mccutter

You pics look like you are running out of gas and/or torch is getting hot.

The cylinder is full, but like you said looks like gas flow issue (or electrode
contamination). External air movement contamination, aka fan or breeze;
turbulent gas flow; or gas restriction in the lines or torch after the regulator.

[randydupree]

I worked at a welding supply for 10 years,granted i worked on trucks and equipment but i did walk through the filling room almost daily.
we hydrostated our own cylinders but i don't remember water being put into the cylinder,the cylinder was dropped into a "well'' in the floor which was filled with water and sealed (like a pressure cooker) and then the cylinder was pumped up with i assume nitrogen.
if the cylinder expanded it would displace the water in the well and up a pipe to a gauge with needle thing,it was an old machine and possibly the newer machines fill the cylinder with water?
I worked for Strate welding,an airco dist.
They had 3 men in the filling room and it would be hard to screw up a fill.
Remember,the same filling rooms are filling Oxegen for medical and breathing air for air fed welding masks and paint shops.

One welding gas that was i think a tri mix had to be rolled after filling,to mix the gas.
It may have been a helium-argon-?something mix?
They filled and then laid the cylinder on its side in a roller thing that gently rolled the cylinder,i guess for a certain amount of time?
I quit there in 1990,so its been a few years.

That tri mix could get screwed up if the cylinder was not rotated i guess,but your using straight argon?

[Oscar]

Originally Posted by randydupree

One welding gas that was i think a tri mix had to be rolled after filling,to mix the gas.
It may have been a helium-argon-?something mix?
They filled and then laid the cylinder on its side in a roller thing that gently rolled the cylinder,i guess for a certain amount of time?

This is not correct, nor applicable to welding gases. Gases that are indeed still in gaseous form will not settle, even while under enormous pressures, UNLESS the temperatures fall to a point where they will start to liquefy (which is really really cold, usually). Air in our atmosphere is a mixture of Nitrogen, oxygen, argon, helium, and a few other trace gases as well. The air in my air-compressor tank does not separate the argon (which is denser than air as a whole) to the bottom of the tank, with the helium gas sitting on top. It just doesn't work that way. In most university level physics classes on thermodynamics/thermal physics such topics are covered and many aspects such as mean-free-path and mean-free-velocity that pertain to gaseous systems are calculated/studied.

[randydupree]

Originally Posted by Oscar

This is not correct, nor applicable to welding gases. Gases that are indeed still in gaseous form will not settle, even while under enormous pressures, UNLESS the temperatures fall to a point where they will start to liquefy (which is really really cold, usually). Air in our atmosphere is a mixture of Nitrogen, oxygen, argon, helium, and a few other trace gases as well. The air in my air-compressor tank does not separate the argon (which is denser than air as a whole) to the bottom of the tank, with the helium gas sitting on top. It just doesn't work that way. In most university level physics classes on thermodynamics/thermal physics such topics are covered and many aspects such as mean-free-path and mean-free-velocity that pertain to gaseous systems are calculated/studied.

wow,i guess the folks at Airco don't know what they are doing?

In your case,onyour home air compressor your compressing air,air already has been mixed by mother nature.

In Aircos case they were pumping pure (kinda pure i guess) argon,and then helium and then maybe Co2 into a cylinder.
So if they pumped in say,argon first it would settle to the bottom of the cylinder,its the heavy gas,so it settles.
Then if they pumped helium its lighter,so would sit on top of the argon (maybe)?
Hell,i never pumped a cylinder in my life,but for 10 years i got to see guys do it,and they used rollers to mix tri gas together.
How many cylinders have you pumped?