A Review/Reference on CO2 Tire Inflators

[Xamllew]

I was frustrated with the lack of information on co2 tire inflators for airgun use so this thread is more of a reference for that subject than it is an actual review. Perhaps other spudders who are looking for info on these as an energy source will search and find this and not be as frustrated with the lack of information as I was.

I bought a cheap Genuine Innovations brand inflator which came with a 16 gram and a 20 gram co2 cartridge, a good deal when you consider the cost of 20 gram cartridges (5-10 bucks a pop). The inflator is a very small valve that easily screws onto a cartridge. Before you purchase one of these you should take your air chamber into consideration, these cartridges are designed to give a single bike tire a fill at about 120 psi before being thrown out so if your chamber has the same or larger volume as a bike tire you're not going to get many charges. My airgun's chamber is 2 cubic inches, a 16 gram CO2 gives me roughly 15 charges at above 300 PSI. I think that the cost of the CO2 outweighs the time and energy required to pump your chamber with a shock pump.

I think these are a great alternative to shock pumps for the budget airgun setup, especially if you value portability, it's simply amazing to be able to carry your entire days source of air in your pocket beside your phone. There is one thing I really dislike about these however and that is YOUR CHAMBER CAN EXPLODE. CO2 is extremely high pressure and without a pressure gauge you have to be your own pressure gauge which is not only conducive to terrible consistency but also very hazardous if you don't trust the quality of your air chamber. If you don't have a built in gauge and you don't know what pressures your gun can handle, DO NOT USE CO2, UNLESS YOU LIKE COPPER SHRAPNEL EMBEDDED IN YOUR STOMACH THEN GO FOR IT MY MAN.

A final note, keep in mind these do not work with your average airgun co2s as they are not threaded. ou can find co2 inflators that use non-threaded cartridges but I've been told that these leak after the first charge.

One more final note, you may want to discharge your gun within a few hours of charging as CO2 molecules are capable of slipping through some porous materials such as rubber.

[Zeus]

I've found them fairly reasonable, just a cheap needle valve type. Painfully low flow of course, not much value in semi auto designs. Performance wise, I'd save my money and buy a decent shock pump. Nothing wrong with getting more upper body strength.

[jackssmirkingrevenge]

Nothing wrong with getting more upper body strength.

Careful though, apparently it will make you lean to the right!

One more final note, you'll want to discharge your gun within a few hours of charging as CO2 molecules are capable of slipping through some porous materials such as rubber. Within 24 hours of charging, your chamber may be completely empty.

If your chamber empties in 24 hours, you might have a leak...

One thing to be aware of with CO2 is that filling orientation makes a difference. Specifically, since it is a liquid at high pressure, allowing the liquid to flow from the inflator to the chamber by gravity will give you a lot more energy than simply filling with gas.

[Xamllew]

One thing to be aware of with CO2 is that filling orientation makes a difference. Specifically, since it is a liquid at high pressure, allowing the liquid to flow from the inflator to the chamber by gravity will give you a lot more energy than simply filling with gas.

Hmm, I will have to try this, it's a tradeoff though as you're using more CO2, so fewer charges per cartridge.

If your chamber empties in 24 hours, you might have a leak...

The reason I mention the leak thing is because people in the biking community suggest that you re-inflate your tire with normal air after using a co2 inflator because CO2 will slowly escape the innertube. I figure since most (or all?) airgun valves use rubber somewhere it's probably a similar occurrence.

[jackssmirkingrevenge]

The reason I mention the leak thing is because people in the biking community suggest that you re-inflate your tire with normal air after using a co2 inflator because CO2 will slowly escape the innertube. I figure since most (or all?) airgun valves use rubber somewhere it's probably a similar occurrence.

This might have something to do with CO2's temperature sensitivity. As it cools, it will lose a lot of pressure, giving the impression of a leak. Air on the other hand is a lot more stable at ambient temperatures.

[Xamllew]

Testing the 20gram cratridge now, this thing puts out a lot of PSI very fast, like over 400PSI in .25 seconds, scary fast.

The reason I mention the leak thing is because people in the biking community suggest that you re-inflate your tire with normal air after using a co2 inflator because CO2 will slowly escape the innertube. I figure since most (or all?) airgun valves use rubber somewhere it's probably a similar occurrence.

This might have something to do with CO2's temperature sensitivity. As it cools, it will lose a lot of pressure, giving the impression of a leak. Air on the other hand is a lot more stable at ambient temperatures.

Wouldn't the temperature of CO2 be at it's lowest upon release? I mean, unless you live in Siberia or something.

Since I've got a bike, a CO2 inflator, and a normal floor pump, I may just do a simple test to see if this is true.

I've found them fairly reasonable, just a cheap needle valve type. Painfully low flow of course, not much value in semi auto designs. Performance wise, I'd save my money and buy a decent shock pump. Nothing wrong with getting more upper body strength.

I agree that for a semi-auto you might want to go with a normal pump, for me though, I'm using a single shot ball valve gun so the chamber dumps completely each shot, my shock pump would leave my arm so sore after only a few hours of shooting.

[Anatine Duo]

I read over on thenakedscientist that co2 is soluble in butyl rubber. The rubber becomes saturated with co2, then is lost to atmosphere on the outside surface of the rubber.

[jackssmirkingrevenge]

Huh. TIL!

[Xamllew]

Hmm, got me thinking about starting to use natural rubber in my seals.

[jrrdw]

Hmm, got me thinking about starting to use natural rubber in my seals.

Only problem with natural rubber is it dry's out and wont hold form and start to leak. You can treat them with oil/s but that will eventually deteariate them causing leaks. Use PTFE O-rings so they will hold up over time.