SpudFiles

Hello, I was thinking about acetylene as the propellant for qev airgun. Will it be safe to shoot with this? I have some carbide so I can produce acetylene from these.

Welcome to spudfiles! Why would you need a combustible propellant for a QEV airgun?

jackssmirkingrevenge wrote:Welcome to spudfiles! Why would you need a combustible propellant for a QEV airgun?

Compressed air may not be a option in this case. Just a guess.

I can only pump 7 bar of air pressure, I was thinking about acetylene because he have high pressure

Thinking you may want to do some research into acetylene, how it's stored and used...and maybe "why".

To get you started;

"Dissolved Gases
Acetylene is the only common dissolved gas. Acetylene is chemically very unstable. Even at atmospheric pressure, acetylene gas can explode. Nevertheless, acetylene is routinely stored and used safely in cylinders at high pressures (up to 250 psig at 21°C).

This is possible because acetylene cylinders are fully packed with an inert, porous filler. The filler is saturated with acetone or other suitable solvent. When acetylene gas is added to the cylinder, the gas dissolves in the acetone. Acetylene in solution is stable."

https://www.google.com/search?q=acetyle ... e&ie=UTF-8

How about dry ice and water, can I just use 0,6 liters fire extinguisher fill it with water and add some dry ice, how much pressure of co2 will it be able to produce?

In case Gipetto's comment doesn't sink in, don't do it. Acetylene makes holes. Acetylene is extremely good at making holes. I'm not talking about the little holes it makes when you light the torch, add some oxygen, and point it at some metal, or the little holes you're hoping to make with your spudgun. I'm talking about the large, house-sized holes it makes when something goes wrong. Plumbers fairly regularly manage to vaporise themselves, usually when transporting acetylene tanks in vehicles. Forget to close the valve, slight leak in a hose, enclosed space, the tiniest spark, and *blammo* - one less acetylene tank, one less white van crowding the roads, one less plumber.

When this happens, folklore tells us that the last thing to go through your mind is liable to be "your arse".

I'd make the 100psi compressed air work, and have in the past.

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Beautiful!

Acetylene Van Explosion "Research", for which read an excuse to blow up a panel van at work

so they are a thing

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That's nothing compared to what they get up to in the Netherlands

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Hectmarr giving classes in the school of weapons to combustion, spud and other variations, that someday I will found, (when I learn something about these topics). That's how I imagine ...
[youtube][/youtube]

One thing that's worth nothing with acetylene... It's actually very difficult to get it to burn. Torches do a great job, but that's what they're meant to do. What acetylene does exceedingly well, however, is *detonate*. Yes, those booms you hear with acetylene cannons are such are actually detonations.

farcticox1 wrote:so they are a thing

[youtube][/youtube]

I don't like this at all. These guys have beautiful cannons and they appear to know what they are doing. I thought we were special. I thought I was special. Seeing those guys with those beautiful cannons feels like I just saw someone with my wife or something. I need to start a therapy thread or something.
These guys in the video are badasses. They tame dangerous fire and make it do stuff they want. They are true human. There is hope for me in this hobby in my older years (as long as I don't die young from taking an aluminum end cap to the face).
I see the appeal of acetylene. It's easy to fuel the cannon with a basic atmospheric mixture while still getting good power from it. However, I can't see myself moving away from hybrid cannons. Propane and air mixtures can practically deliver as much power as you can build for and manage to compress in the chamber. My heart is with the propane powered hybrid cannons. I can't wait to build another one.
Seriously, I bet a decent volume 4X piston cannon would out perform those acetylene cannons. You'd need to bring a big air tank with you though, but that would just replace their acetylene tank. The propane tank is so small it doesn't even count.