Terribley STINKY CO2?

I have been kegging since I have been brewing, have filled lots of tanks, lots of times, many different tanks for that matter. I recently filled a 20oz paintball tank that I use for my portable setup and I don’t know why, but I sniffed the co2 while it was on the way out of the QD, it was terrible smelling. Hard to even describe the smell; rank, musty, funky, maybe slightly metallic. I know what co2 smells like, at least what its supposed to smell like. Anyone have any ideas what may be the problem. The tank itself has been filled 3 times before, never had this issue, its less than a year old. I filled it at a used sports equipment store? It smells so bad that I wouldn’t even think of hooking it up to dispense beer with. I am going to double check that it is not eminating from the reg/hose/QD itself, but I sort of already did this by removing these items and then releasing a bit of co2 straight from the paintball tank, at which point I picked up the funk in the air. I am going to hook the reg/hose/QD up to another tank just to be sure. Any other suggestion, other than draining and refilling and hoping that it goes away?

When in doubt, I follow my gut.

My gut, and your’s probably, too, is saying give it one more check and then if it still smells wrong, then:

  • conclude the used sports store guys filled it with junk,
  • you need to dump the tank and get it refilled somewhere else from now on.

DT

I have heard that paintball tanks can have oil added to them for the guns, and what your description sounds like old, rancid oil to me.