How To use a fire extinguisher as a chamber

[Killjoy]

I agree with you pete, but its seems like new people never take the time to research or look through the forums for what they need or just half read a post and ask a question which would have been anwsered if they had read the post throughly.
Usually its nothing real irritating, its just that in this case there was a lot of stuff that should have made Biker question wether his question was appropriate (which it wasn't).

[MrCrowley]

Its not even a pneumatic, its not even a gun, its a how to on making a custom fitting.
I don;t give him answers because he doesn't deserve them.

I totally agree, Judgement arms and Biker983493 read the topic before you post. Judgement you thought it was a pneumatic meaning you havn't read or mis-understoof the topic. Same with you biker its not a gun either. Asking what I use for ignition on a modified part is beyond stupidity. Its like asking "What is the source of power for that lamp shade?"

You don't power a lamp shade, you power the light bulb.

[frankrede]

Judgment arms, seriously stop defending that guy. Theres no point in it.


Edit:well put crowley.

[potter]

That is a good idea if i might just say good job

[BIKER180360]

man im not even in highschool yet so lighten up i mean how many 14 year olds even know what a spud gun is. i think i'm doing pretty good for my age 8) atleast i'm trying

[frankrede]

Just keep trying, thats the only advice I'll give to right now.

[judgment_arms]

MrCrowley, nobody on this earth is perfect; at the very least I tried to help Biker.

Frankrede, you and MrCrowley both need to learn some respect, how can you remove the speck from your neighbor’s eye, when you have a plank in yours? Put your selves in Biker’s shoes…

Now Biker, you need to learn, I agree with them on that, we all do.
14 years old, well I’m 15 and I’ve been in to air cannons for about a year, we all start somewhere, I browsed this website, read TONS of topics, spent countless hours researching, before I even made my first cannon, it was a few months later before I joined and made my first post, which, for the record, was retarded... my point is, we all need to learn, don’t ask people questions that could be answered by five minuets of searching, I.E. “how do you modd a sprinkler valve”, or “what should I use for ignition”, if you do your research before hand, then you don’t seem as retarded later. I hope you haven’t made you first cannon yet…

No we are quite off topic, let’s drop it, get back on subject, and STOP FLAMING NEWBIES!!!

[Wombat]

Sorry for posting in such an old thread, but I actually do have a relevant question.

I have this empty fire extinguisher that I'd like to use in a pneumatic cannon. The thing is, it's one of those dry chemical extinguishers, and I'm not sure if its designed to hold air pressure. If I remember correctly, I believe that fire extinguishers work by actuating a valve containing a small amount of high-pressure gas, which then blows the chemicals out through the nozzle. I wasn't so sure if the actual contents of the extinguisher are under and pressure.

So my question is, would any kind of fire extinguisher be able to hold a reasonable amount of pressure?

[thespeedycicada]

if its metal well what do you think? yes it will be able to hold a "reasonable" amount of pressure at least 1000 psi.

[Wombat]

Please do not post if you don't know what you are talking about.

[windshrike]

Wombat: The extinguisher uses the venturi effect to 'suck' the chemicals out as the high pressure gas moves out very quickly, at negative pressures(see the Bernoulli effct as to why). They can handle very high pressures, the CO2 ones at least 1250 psi, and the one you have should take at least a 1000 psi. Oh, and thespeedycicada DOES know what he is talking about.

[Wombat]

Alright, well I guess that settles it, but I do remember reading that extinguishers only held around 200psi. Here is a link where I read it-
http://hypertextbook.com/facts/2005/VictoriaPoon.shtml

(Although, in that table the highest pressure listed was 5861kPa, or about 850psi)

[DYI]

Dry chemical fire extinguishers have a rated pressure, and a test pressure. Generally, they are rated to about 195 psi, and are tested to 585 psi (3x the rating, which isn't a coincidence). Using them at anything over 500 or so is a very, very bad idea, and I wouldn't recommend using them at any more than 300 psi.

As far as I know, CO2 FEs use liquid CO2, which means around 800 psi, so they are rated for at least that, and would burst well over 1000.

[battlemonkey]

ah but co2 fire extinguishers have a co2 chamber inside them wich makes them much harder to modify. the tank that holds the co2 is peirced and then flows through the powder.
and to what was said earlyer. i'm only 14 and I perfectly know what a potato cannon is.

[MrCrowley]

Thin aluminium extinguishers are rated to 300psi usually, they could blow at around 800psi I would say. Keep under 300psi you should be fine.