Summary: Two new Argon/CO2 disposable cylinders seem to be nearly empty. Are they?
Details: I purchased (online) two of the small disposable cylinders of welding gas (boron/co2 mix 110l) and put one in my old Clarke 100E Mk 2 mig welder the day they arrived. I turned the regulator up to about 3 which is usually not far out and tried to weld - no gas. I had to turn the regulator up to the maximum (6) to get a low hiss.
A part used pure CO2 cylinder I've had for several years works fine at position 3 on the regulator.
By way of investigation, I weighed both new cylinders and they were a good bit lighter than the part used CO2 one. I screwed the regulator onto the other new one and also had to turn it up to almost 6 to get an audible hiss (direct from regulator - ie not connected to plastic tube).
I told the retailer that I suspected they'd been leaking or not filled properly and they promptly sent me two replacements FOC. Those two are both exactly the same - ie lighter in weight than the old CO2 cylinder and much lower pressure - would require the regulator at max to weld.
Weights:
Old part used cylinder of CO2:
1518 gramsNew Argon/CO2 cylinders:
1) 1393 grams 2) 1367 grams 3) 1364 grams 4) 1388 gramsCan I expect CO2/Argon mix to be at a similar pressure to pure CO2 and am I right in assuming faulty goods or is there another explanation I haven't thought of?