Propane Pneumatic

[FreakyShotGlass]

I went paintballing and now I'm addicted. I want to make my own marker and I have two ideas, either a combustion like the Tippmann C-3 or a little design of my own.
I found a nifty little chart on the vapour pressure of propane and at the temperatures we get here it wouldn't go below 100 psi in the day, so I thought why not use propane for a pneumatic.
I would cut off the torch part of a Bernz-O-Matic torch to back behind the regulator and then attach a tube leadind to a small expansion chamber and then a 3/4" sprinkler valve. Any ideas, do you think it is possible?

[meatballs]

That might work, i've had the idea myself...the problems i see are with the volatile nature of propane. you would have to be sure that there was no oxygen in the pressure chamber. otherwise you have a bomb. it would also be important that when you release that much propane into the air you don't have any ignition or inhale the propane. other than that it should work, but it would probably be fairly dangerous.

[FreakyShotGlass]

I would only use a very small chamber, not more than 15cm x 20mm so not much propane would be released.

[hi]

DR made one one time. he used a bottle of propane and a torch head. it was i think a tennis ball launcher. it looks really cool. It was on spud tech. ill see if i can get you a link. I think he also use a 1'' sprinkler valve.

[hi]

http://www.spudfiles.com/spudtech_archi ... hp?t=15564

there you go.

[FreakyShotGlass]

Thats just like what I want to make except I am going to use a much smaller chamber so that less propane is released each shot and I'll be moving around so it should disperse pretty quickly and not build up in one area.

[singularity]

well propane should only ignite in a 1 to 10% ratio with the air. so even if there was oxygen in the chamber it shouldn't be a problem because it would be over saturated with propane.

if you plan on using your gun on a real field they might get pissed off and not let you play because of safety reasons. thats what happened to me. the other thing is you should probably get your gun to at least fire semi auto if you want any chance of surviving. unless you plan on sniping from pretty far away with it

[VH_man]

I know that a poor-mans way to fill Gas airosft pistol mags is with a camping propane cylinder....... works fine....... ive seen it at airosft feilds before......

[rad14701]

Sounds more like a combustion than a pneumatic...

[hi]

ok people, lets get one thing strait. unless it is ablolutly in perfect conditions, the propane will NOT ignite. Ever wonder why the flame on a BBQ doesnt go into the tank and exlplode? its because there is to much propane. If you so much as get the tank to 2 psi it wont ignite. its simply to much. Thats also why if you cover the air holes on a torch it wont ignite. it wont explode, period

[VH_man]

It would be fun to dry-fire it at candles though...........

[hi]

It would be fun to dry-fire it at candles though...........

thats been done too with those tiki torches. it made a nice flame. i think it was on spud tech, but not sure.

[rad14701]

Thinking back over 25 years, during fire training, I seem to recall a figure of something like 6% propane or natural gas as being the optimal fuel/air mix required for combustion... And using a clear test chamber for demonstration purposes the instructor from the local gas company demonstrated that either too rich or too lean of a mixture simply won't ignite... Other gases are far more forgiving when it comes to mixture ratios than propane and natural gas...

[benstern]

I was the first to make a propane pneumatic. DR got the idea from me.
http://www.launchpotatoes.com/forums/viewtopic.php?t=21
And yes, that was me w/ the tiki torches!

Btw even if the propane ignited in the chamber it won't matter.. it's rated to over 100 psi right?

[hi]

@ ben stern, about how many shots did you get per tank with that? im just talking about the normal cans of propane that are at the hardware store for $3. i might just use it as a porable air source.