SpudFiles

I was thinking about using a 12gram co2 bike pump to fill one of my mini pnuematics. My question is, is there any danger that using co2 directly into pvc will cause the pvc to get cold? I heard that chilling pvc greatly increases the chances of it shattering.

I am in the process of writing this exact question lol. Thanks for posting and saving me sometime. I want to know too!!

-shadow

Yes when pvc get very cold it also get very, very brittle i wouldnt use co2 if i where you just stick with an air compressor or a regular bike pump and you should be ok.

use steel for pvc, even a 6" piece.

what do u mean, kvinceo? Do you mean put steel between where you fill and the pvc parts?

How brittle? I am going to be filling to 60 psi, maybe less. I dont want to push my cannon to far. I was going to use this pump in an airsoft shotgun/grenade launcher.

Cold will also make rubber brittle (as in bicycle tires), but since it’s must be safe to use Co2 in bicycle tires, which are exposed to a lot more stress than most pressure chambers, I would conclude that it should be safe.

I did it with my cannon to 30psi. It filled it right quick to in about half a sec. I got afraid of it rupturing and stopped. So would it be safe to go to 60 psi?

If you can, put a thermometer into your chamber before you charge it. I have the same little pump thing, and when I spray it on my hands it's not that cold. Not cold enough to make pvc prone to shattering unless you're above its psi rating. If you look on the pipe you're using for your chamber it says X psi rated at X degrees. Mine is rated at 40deg. farenheit, which is pretty cold. Just check the temp of the outflow of co2 from the thing and you should be okay. My guess is that you can use it safely.

I all so found that out. I found out last night. I buy crappy little bike tubes for there valves and before I had cut it up, I put a ton of air into itwith my CO2bike pump. The tire felt like it was before. It was not cold, just room temp. Its a good thing to find out, now I can fill my chamber to 60psi No problem.

Or an easy way to fill safely:
Buy an air hose, put a barbed fitting on each end. Put one fitting into the PVC chamber. Put reducers onto the other side and screw in a schrader. Put the PVC chamber behind a concrete wall or something like that.

I don't know about you guys, but my co2 bike filler sometimes shoots out little ice balls that have vapor stuff coming off them. It may not feel cold, but that shows that it is cold, so just use metal for your chamber. That way you won't have to worry about putting in too much. Another thing too, I read here on spudfiles that sprinkler valves aren't designed to withstand high pressures with cold temperature.

Ive been researching this topic for two weeks because I made this really sweet gun out of PVC and I didnt know at the time that CO2 had hazards but I didnt want my gun to go to waste. I'v found that there is a reletively safe way to do it.

If you connect a Remote Coil from the CO2 canister to a metal pipe and connect the other end of the metal pipe to a high pressure ball valve (for regulation) and finally connect that to the PVC chamber then it should be ok to use. HOWEVER I was told that you need to let the CO2 sit in the metal pipe for a short period of time before you slowly release it into the PVC because it needs time to heat up and become a gas since it was in a liquid form. Were probably talking 30- 60 sec. But that's all I've got after two weeks.

By the way, not to be off topic, but I just like to show off my gun that's not quite done. This is what I'm hooking the CO2 tank up to. 8)

A co-axle auto?

Red/black paint looks nice

I'm wondering if thats really crazy pvc pipe, some kind of hose or overbent copper at the back...

its semi auto, auto if you hold the trigger (that's not there yet) down.

And no that pvc is just crazy!!! ...