fire extinguisher CO2

[wavestarved]

Hey all, new to this welding lark but have read heaps on here and learned much. I've just bought a Clarke 151en mig and had a go gasless as that's how it comes, and quickly decided that a reglator and some gas was needed. Today I sourced a CO2 reg made by Parweld and all the gubbins to get it on my mig. I also sourced a 2kg CO2 fire extinguisher which was sealed and was told it was full. When I put the reg on (direct fit where the horn pipe should go) the dial reads barely above empty. Is this cos its only a wee bottle or is it in fact nearly empty???
The other thing I noticed is that when disconnected from the mig and I turn the reg on it kind of spits a bit and comes out as a fine cloud; is that normal?
I haven't had a go welding with it yey but everything went together easilly and the gas comes out of the torch when I press the trigger so I'm guessing its working.
Missed the shop for some wire so the real test will have to wait til tomorrow.
Thanks for any help or answers
Jase

 

[Robotstar5]

Is this cos its only a wee bottle or is it in fact nearly empty???

The cylinder should have the weights stamped on the neck, when we get ours checked at work the engineer weighs them to confirm they are full.

 

[wavestarved]

Good tip, thanks for the quick response. I'll check it tomorrow.

 

[ford34/2]

weights

If the yearly test sticker is still on you might well find the engineer logged the weight , also check the stamps on the bottle, they are punched into the metal, they equate to empty and to filled.

not too sure if a gauge reads pressure on a C02, just the way the gas contents are it reads full till the very last dregs come out and its---yes empty. weighing it is the secret. I think the gauge might well be reading what it is allowing out of the bottle to the welding machine/gun and not what the contents of the bottle are.

any friendly fire extinguisher service company just might refill it for you, there is a thread on here with nation wide outlets who will service various bottles.

Stan

 

[shenion]

Fire extinguishers have a dip tube so they dispense liquid. Some here use them upside down.

You may have issues with the reg freezing or becoming unstable.

CO2 is usually around 950PSI regardless of the size of the bottle. That is the vapor pressure of the liquid at room temp. My reg has been sitting at that pressure for 3 years (does change with temperature.)

 

[wavestarved]

Well, tried a few practice welds with some fire extinguisher Co2 and I'm really pleased with how much cleaner the weld is, virtually no spatter at all, and you can see what's going on much better. Still need more practice getting decent penetration, but the stuff I was practicing on was about 6mm thick today so I wasn't expecting miracles.
The problem I'm having is with the regulator getting all iced up. I've tried turning it upside down as suggested (cheers Shenion) but it makes no difference. Think I'll have to get a proper bottle and keep the extinguisher for, well emergencies.
If Co2 always welds this clean though I won't bother with argon. I'll post some pics when I have a practice on more suitable material. Cheers all.

PS, cool fish!

 

[shenion]

When you turn the tank over, it maytake a considerable amount of use to empty the dip tube.

CO2 can be done with not much spatter if your wire feeder is consistent.

 

[wavestarved]

Cheers again Shenion
I'll try reattaching the extinguisher nozzle and giving it a couple of blasts with it upside down see if I can clear the dip tube then give it another go.
Just realised why I might not be getting the penetration I expected...forgot to swap the leads over from the gasless set up; Rookie error, DUH!

 

[bigrab]

Hi.

I've been using fire extinguisher co2 for about two months now, costs £10 a bottle and is not too bad for welding. A 5K bottle of gas has a nett weight of about 8K. The pressure stays at the same till the bottle is totally empty! And the vapour is because co2 is a liquid. I had an old 2.5K extinguisher laying around so set that up first and it is still the same pressure after about two or more hours of welding at 10Lpm, but lighter.
I laid it on its side for a while but now have it set upside down by using two shelving angle brackets to rest the bottle on and a belt to hold it at the top. The Extinguisher handle has holes through which you can push a pin (usually attached to the bottle) to keep it open.
I would try the Argon/co2 bottles but the expense here is murder!

Bigrab.

 

[wavestarved]

Cheers Rab
I think I need to knock something up to hold the bottle upside down if I use it again, the shelf brackets sound a good idea. My extinguisher is only reading just above empty on my regulator guage despite it being sealed and sold as full. Who knows though eh? I think I might try to rig up a coupling for the regulator so I can mount it somewhere other than on the top (or bottom when inverted) of the extinguisher.