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can u put propane in a Pneumatic cannon instead of air??
Posted: Mon Nov 03, 2008 6:16 pm
by cannon monkey
well umm like the subject name says it all
can u put propane in a Pneumatic cannon instead of air??
Posted: Mon Nov 03, 2008 6:22 pm
by Demon
You can, but it not a good idea.
You may explode with your house if you are shooting in a basement.
You will pay a lot compared to an bike pump or aircompressor.
Posted: Mon Nov 03, 2008 6:26 pm
by cannon monkey
wat about propane tank filled with air would that work if soo how would i do it
and how much psi can it hold
( them big tanks u see on the grills in a BBQ)
Posted: Mon Nov 03, 2008 6:29 pm
by Fnord
Obviously, (as demon stated), it's not a good idea for indoor use with a larger cannon. Propane is, however, a good idea for a small, portable bbmg that you don't need an air compressor for.
You'll be limited to about 120 psi at room temperature.
Oh, and if you're a tree hugger, propane isn't good for the ozone
wat about propane tank filled with air would that work if soo how would i do it
This, however, is a stupid and badly written question, so I'm not going to answer it. Propane tanks are safe to 150 psi under normal conditions.
Posted: Mon Nov 03, 2008 6:33 pm
by cannon monkey
i mean is it safe i never take it over 100 psi
it 3 inch chamber 2 feet long modified sprinkler valve 2 inch barrel is it safe to use propane instead of air
Posted: Mon Nov 03, 2008 7:17 pm
by Lentamentalisk
It has been done before:
http://www.spudfiles.com/forums/bolt-ac ... 15568.html
If you are not firing it indoors, or anywhere with bad ventilation, then you are completely fine. The only thing you have to be careful about is the tank freezing.
Pressurizing a propane tank with air is absolutely useless for your circumstances. The entire point of using propane is that it is stored as a liquid, so you can get a ton of shots off of it. Air does not liquefy until much higher than 3000psi, so you would be holding just a tinsy little bit of air.
edit:
also, on the comment about breaking the bank, not so much. A bottle of propane costs only $4 if you like being ripped off. If you already have a 20lb tank, than you can get it for less than a 1/4 that, at under $20 a fill, at least where I live.
Ok, edit again:
If you are concerned about explosions and the like, then all you really need to do is burn off the propane after each shot (which looks freaking awesome btw...) I would suggest doing this by attaching a glow plug to the end of your barrel, assuming you don't mind having some batteries. The other option, is to take a propane torch, dial it waaaaaaay down, and just have that sticking out by the end of the barrel to light the gases.
Posted: Mon Nov 03, 2008 7:38 pm
by benstern
I used propane in my pneumatic cannon back at the first las vegas spudgun ipla meet. Go ahead as long as you are outside.
Posted: Mon Nov 03, 2008 7:40 pm
by cannon monkey
ok how can i put it in i have a tire valve on the end of my cannon
and if i buy them small green cans for portable gills how many shots can i get out of one cannon ( 4 usd can)
and do i need a regulator if soo is there a special kind?
Posted: Mon Nov 03, 2008 7:51 pm
by Lentamentalisk
step 1 is use punctuation and capitalize ur "i"s and not use txting slange such as "ur" or "r"
Then we can move on to sophisticated talk, such as how to not blow your face off of the planet or asphyxiate yourself.
You will need to create your mounting system. The method that many people use it to take a propane torch, and unscrew the torch head, and thread that on to what ever. Look at propane meters for combustion cannons for inspiration (just ignore the actual meter part of it, and focus on the attaching to the tank portion.)
One last note: it is only called green gas when it is used in airsoft, so the canisters that you are referring to would be called "1lb propane canisters".
edit:
as to the regulator question, look at the link that I gave you before. On page 2 there is a graph of vapor pressure vs. temperature. If you want to use it at any pressure other than the pressure the graph says at your given temperature, then you will either need a pressure gauge and a deft hand on a needle valve (or if your propane torch has one, that will work too,) or you could go with a cheap regulator from
harbor freight.
Posted: Mon Nov 03, 2008 10:54 pm
by DYI
This is a FORUM, not a chat room. Your grammar and spelling are appalling, and your queries are nonsensical. It's obvious by the style of your "writing", if it could be so called, that you're capable of mangling the language significantly less than you are currently, so why don't you? Is it disrespect, or just shear laziness?
If you have a series of inane questions to ask, you could at least try to make them legible.
As to what seems to be your question: the "Coleman Stove" type cans (the short, fat green ones) hold about a pound (454g) of propane. Propane has a molar mass of 44.11g/mol, and you can find the approximate molar density of any gas by using pv=nrt, where r is the universal gas constant (about 8.31 kPa*L*mol<sup>-1</sup>*K<sup>-1</sup>.
Posted: Tue Nov 04, 2008 1:43 am
by i-will
they way i do it is saw off the top half of the brass torch fitting that comes with it. sand the rough, sharp edges to a smooth surface. push one end of some plastic tubing over it and secure it with a hose clamp. secure the other end (also with a hose clamp) to what ever u want to pressurize. i usually get the tall blue cylinder but the torch fitting should still fit perfectly on the short green one.
<a href="
http://s90.photobucket.com/albums/k273/ ... ankmod.jpg" target="_blank"><img src="
http://i90.photobucket.com/albums/k273/ ... ankmod.jpg" border="0" alt="Photobucket"></a> if u want more flow from the flow regulator i can find some old pic of mine to show u how. i hope this was helpful.
Posted: Wed Nov 05, 2008 9:44 am
by benstern
I'll take a picture of my propane fueling system and add it to this post when I get home.
It's a propane torch with the long piece unscrewed (need a vise for that) and a female quick connect attached with the help of a male compression fitting to regular NPT thread adapter.
Posted: Wed Nov 05, 2008 2:12 pm
by starman
i-will wrote:they way i do it is saw off the top half of the brass torch fitting that comes with it. sand the rough, sharp edges to a smooth surface. push one end of some plastic tubing over it and secure it with a hose clamp. secure the other end (also with a hose clamp) to what ever u want to pressurize. i usually get the tall blue cylinder but the torch fitting should still fit perfectly on the short green one.
You don't have to saw it off. You can use 2 pipe wrenches and unscrew that pipe out of valve unit. It will be stuck in there really well so be prepared to grip hard and muscle the wrenches...you here the adhesive "snap". Use a 1/4" male tube compression to 1/4" male NPT brass adapter to screw into the valve (with teflon tape of course). Works great!!
Posted: Wed Nov 05, 2008 5:06 pm
by cannon monkey
and it wont mess up my cannon? if I am using propane?
Posted: Wed Nov 05, 2008 5:12 pm
by benstern
No, it will not.