SpudFiles

Has anyone seen and/or used these to power a cannon? From one page I read that it is a propane/butane/lp gas combination in a nice small package. What would be the ideal ratio of air/fuel for this stuff? I can't seem to find any answers anywhere, so I thought I would ask it here. It seems like it may be a decent alternative to a heavier 14.1 or 16 oz propane bottle for smaller cannons (rifles or guns to those of you who might take offense to a 'little cannon' )

Figure it contains pure propane and use propane's ratio of 4.2% for additive loading, or 4% for displasive loading. That may well be close enough.

Or...

Search for the MSDS sheet for the Paslode cartridge. It must be out there somewhere. MSDS often have more info on exactly what is in a container. Once you know the proportion of the various gases you can calculate the correct volume as the weighted average of the values for the gases. If the cartridge contains 80% propane and 20% butane then the correct percentage is (0.8 )(4.2) + (0.2)(3.2) = 4% Check the spud wiki page on fuels for the percentage for other fuels.

Or...

Drop the paslode cartridge idea and use a cheaper pure butane source like the cartridge used to refill butane lighters.

I believe the paslode cartridge and the butane refills have the same valve setup. How are you going to control that valve?

Jimmy,

Drop the paslode cartridge idea and use a cheaper pure butane source like the cartridge used to refill butane lighters.

Well, I want to get away from the butane pressure/temp rise and closer to propane which will give me a higher pressure (normally) at STP.

The valve will be pretty much open all the time, like plugging in a CO2 cartridge on a BB gun. It will be regulated and metered for a 2.9" x 8" chamber with an automatic meter. The higher pressure is desired to cut down on the meter size.

I'm in the process of designing another rifle, without the rifling If all else fails, I'll have someone fabricate a refillable bottle for propane that will hold about 4-6 oz. Hmmm, has anyone else done that?

Edit: Never thought about an MSDS, but I've found one. Flammability limits are ~2 to 10, according to the MSDS. I'm assuming that is %.

It lists the ingredients as Propylene(60-90%), Butylenes(10-40%), and Propane(<3%), by weight. Pressure at 70 deg F is ~ 100psia, slightly lower than propane, but much higher than butane. A look up of propylene isn't much help, except that its a byproduct of petroleum refining.

None the less, if it can drive a nail into wood, its worth a try.

I have considered building a small propane tank. I decided to just use black iron pipe fittings, a schrader, and a needle valve (this was for a small torch) Then I found out the needle valve leaked, and gave up.

leaking propane=bad.

also, only fill to about 34% of the volume, otherwise, it will build enormous pressure.

http://www.warpig.com/paintball/technic ... mics.shtml

I sell the stuff at work.
It would be a nightmare to create a fitting for it and it is probably not that much more powerful than well mixed propane to make up for the extra cost and trouble.

You will still need a fan and meter.
Paslode tackers have them as well.
You can hear them vent after each shot.

We had a representative of the company over at work some time ago, but he knew nothing about the content mix, quantity used, chamber size and fuel to air mixture...
Neither did he know where the air for combustion came from.
He figured it was in the fuelcell...dumb bastard...

He must have thought I was a geek...or felt stupid for not knowing much about it...either way he avoided me after that...

Sales people are the worst when it comes to actually knowing anything technical about the products they represent. The place where I work, these guys try to offer the customers help with troubleshooting and repairing small problems. They end up turning them into big problems and then call me at production to get it fixed. I stopped traveling and make them send stuff back for replacement. I took this job to keep from traveling all over the world!

Anyway, I'm thinking of an aluminum canister, welded. I can buy the stuff at McMaster and have a local weld it for me (I'm not good enough at aluminum, yet). I was thinking more like the valve on a paintball 20oz tank instead of a schrader. I'll have to check about the gaskets and Orings and see if I'll have to change them out. I'll put a vent valve on it as well with a straw at about 75% full to keep from overfilling it. I think 1.5" pipe will work.

ramses wrote:also, only fill to about 34% of the volume, otherwise, it will build enormous pressure.

That's based on CO2, not LPG. You can't apply numbers for one to the other.