Gas leak

[Dessieb2022]

Hey everyone, just hooked my blackline mig up to gas bottle and I was checking for leaks. Regulator and all is fine but I heard a leak from inside the welder. I took the case of the welder and have found a leak at a brass fitting which was tight and had plumbers tape on it. I removed the fitting and redone the tape and sweetened it up again but still no better. Any ideas?
Only thing I can think of is that the pressure was too high for the fitting, showing 80 psi when it leaks? Mind you I'm a novice at this type of thing lol

 

[waddycall]

How many wraps of tape did you put on? Needs about 10 or 12 for that sort of size. You will get numerous suggestions to use other compounds etc which may well work but PTFE tape should do fine.

 

[Dessieb2022]

I didn't count but guessing probably about 3 or 4. I didn't realize it needed so much. I will try that now, thank you. Didn't expect to have to take apart a new welder so soon to fix problems lol

 

[Dessieb2022]

Still leaking like a bar steward...

 

[eddie49]

Only thing I can think of is that the pressure was too high for the fitting, showing 80 psi when it leaks?

Where/how are you measuring this? The regulator output is normally scaled in flow - litres per minute, not pressure. The actual pressure should be a tenth of what you are seeing - 3 to 8 psi.

 

[Dessieb2022]

I have a disposable regulator with a gauge showing up to 100 psi or so. I opened the valve a bit and tried welding but was getting porosity until I had it opened near max and reading around 75 to 80 psi.

 

[octo0072000]

I have a disposable regulator with a gauge showing up to 100 psi or so. I opened the valve a bit and tried welding but was getting porosity until I had it opened near max and reading around 75 to 80 psi.

you sure that's not lpm (litres per minute)

 

[Dessieb2022]

Just looked again, max of 85 psi.

 

[500e]

There is a ptfe tape for gas usually on a yellow spool, Calor gas shop should have it seems to be a thicker material

Gas PTFE tape vs.water PTFE tape

Is there any difference between gas PTFE tap and normal water plumbing PTFE tape? They look identical, to the naked eye. Is it OK to use water PTFE for gas, or vice versa? Mike

www.diynot.com

 

[waddycall]

Are you able to remove the solenoid? Might be worth checking for a split.

 

[waddycall]

Also might be worth posting a picture of the fitting disassembled from the solenoid so we can see what you’re dealing with.

 

[eddie49]

I'm not familiar with that regulator for disposable bottles, but I don't think you should be getting gas out of it at 80 psi.
Are you sure it is the correct regulator, new, working, and with the right gauge fitted to it?
As you can see, this one is calibrated in litres per minute ( L/m ) and cubic feet per hour ( CFH ):

 

[octo0072000]

Just looked again, max of 85 psi.

View attachment 359600

gauge is cylinder content the black knob is line pressure should have a scale on the side

 

[Dessieb2022]

gauge is cylinder content the black knob is line pressure should have a scale on the side

I'm not sure I get what you mean, the black knob has a plus and minus on it. The more I open the valve knob the more the gauge rises. I don't hear a leak from the solenoid fitting till the pressure on the gauge is about 80 psi. That being said it may be leaking at low pressure too, I'll have to spray it and check.

 

[Dessieb2022]

I'm not familiar with that regulator for disposable bottles, but I don't think you should be getting gas out of it at 80 psi.
Are you sure it is the correct regulator, new, working, and with the right gauge fitted to it?
As you can see, this one is calibrated in litres per minute ( L/m ) and cubic feet per hour ( CFH ):
View attachment 359613

Yes it's new, bought it from static arc. Was sold for Co2/argon disposable bottles. See photo

 

[octo0072000]

that's not how a mig regulator should work try about 10psi should be plenty as long as you can just here a slight hiss at the torch should be ok
try ordering a pea shooter for the gas
one of these

Pardon our interruption...

 

[eddie49]

gauge is cylinder content the black knob is line pressure should have a scale on the side

There are twin-gauge regulators for sale to fit disposable cylinders, but the bottle content gauge is typically calibrated to 200 or 250 bar, which is 3000 psi.

 

[Dessieb2022]

Also might be worth posting a picture of the fitting disassembled from the solenoid so we can see what you’re dealing with.

I will do this the next chance I get, it is pretty much brand new so shouldn't be any damage from the factory but you never know I suppose.

 

[Dessieb2022]

that's not how a mig regulator should work try about 10psi should be plenty as long as you can just here a slight hiss at the torch should be ok
try ordering a pea shooter for the gas
one of these

Pardon our interruption...

I will order one of those. I'll try 10psi but the reason I had the pressure up around 80 was because anything under that I was getting porosity.

 

[eddie49]

This is the eBay listing for the regulator & gauge that StaticArc have sold to you:

Pardon our interruption...

I think it is rubbish - and possibly you got a faulty one too.
The maximum output pressure is quoted at 4 bar = 58 psi, and input 130 bar = 1885 psi.
It says "complete with gauge to measure gas remaining in bottle". That gauge marked 85 psi would not last long if you ran the input pressure up to the maximum of 1885 psi.

So what is the pressure of a disposable Argon/CO2 cylinder? According to this website:

Disposable Gas Cylinder- COLLECTION ONLY – Bridgwater Welding Supplies Ltd

it is 60 bar, which is 870 psi. On a standard disposable cylinder, that "85 psi" contents gauge is going to be way overloaded. Apparently you have run it up to an indicated 80psi and it has not exploded, so maybe the scale markings are just wrong.
I would send it back to them, saying that a gauge marked 85 psi cannot be right for a cylinder that starts at 870 psi when full.
Get a proper twin-gauge regulator for disposable cylinders. Or better still, ditch these money-pit disposables and go full-size!

As for the porosity - remember that in this thread

Blackline 200 gasless welding set up

Hi everyone, new member here. I have searched through previous posts but didn't really get a definite answer to my query so here goes lol. I recently bought a Blackline mig 200 and I am wanting to weld flux core to start with. Now I know it's supposed to have an auto sensing plug or something so...

www.mig-welding.co.uk

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