Converting a Propane Cylinder

[nathanhd123]

Ok so here is the cylinder I have got. Its rated to 30 bar, or at least it says 30 bar on the side. How to I convert this to use as an air tank? I would like to keep the threads on the top as they fit my gun I am making.

[Crna Legija]

If the threads on the top fit then all you need to do is remove the valve inside drill the hole as big as you can get it and your done. If the tank can rust and your going to be filling it with air not co2 or another gas i would suggest covering the inside with anti rust paint.


looks like it has a safety valve on the side it will probs pop at roughly 30ish bar so id keep it at -25 bar

[nathanhd123]

How can I make sure its empty as I do not have a torch attachment

[POLAND_SPUD]

pull the core of the pressure relief valve (that's that off centre thingy on top of the tank)

[nathanhd123]

Heres the gun. However I am rather nervous about drilling through a ropane tank. Any tips?

[Gaderelguitarist]

Do what poland said and try to release all of the gas through the popoff. You could also go buy the torch attachment and just run it outside. Don't work with it unless you're confident in your safety.

[Gun Freak]

Just go buy a propane cylinder, they are 3 dollars and the same thing as a MAPP cylinder. A new one will be safer than this old beat up one.

[warhead052]

I have a tip for you. If you don't want to drill through the MAPP cylinder, use a tee with a schrader in it instead. I know its a pretty old way of doing it, but it works right? Its better then spending 30 minutes drilling through the side of it to installed a schrader... I did that with my fire extinguisher vortex cap... Took 30 minutes and I broke 2 drill bits!


Nice job with your set up, but seriously. Just use needle nose pliers and pull (or push) on the safety pin to let the gas out. Thats all.

[Gun Freak]

Warhead, he wasn't drilling into the side, he was drilling through the neck to get better flow.

[Goats spudz]

release the gas first???

[nathanhd123]

When I pushed the pin in the main valve some gas came out. It wont let me pull on the safty valve( the side one). It seems the gas is out but when I shake it it sounds like there is a tiny bit of somerthing left in.

[warhead052]

Warhead, he wasn't drilling into the side, he was drilling through the neck to get better flow.

Ok, thanks for the clarification.

[velocity3x]

Submerge the tank in water and hold a valve open until the tank eventually fills with water. It would then be safe to drill.

[al-xg]

Yep fill the tank with water, even when there is no pressure left there is still quite an amount of gas in there.

I use this technique to empty a butane tank.

[mattyzip77]

go buy the valve, do what you need to do, and then just return it, and say it doesnt work!!! always works for me, just save your receipt!!