Chambers from propane cylinders

[dinsdale]

I'm thinking of making an air chamber for a pellet gun out of a used propane cylinder (one of those disposable green stubby ones).
I figure that if I screw on a fitting to hold the valve open, i should be fine drilling a hole in the base for a schrader valve, and then tapping a new fitting into the top.
Does anyone have any experience doing this?
If so is there anything special I should know?

[benstern]

Be sure to fill it with water first! This will remove any and all propabne left in it!

[dinsdale]

How do i fill it with water before i rip it apart?
It has a pin valve deep in its nozzle, and one on the shoulder, no where i can pour or pump water into

[boilingleadbath]

Why would you want to put the shraeder through the back?
Personaly, I'd use the back as a stock, although I admit it's not terribly good for that job as far as ergeromics go.

I'd put the shraeder through the "top", next to the outlet. (you'll need to use one of the clamp-style ones, as the walls are only an estimated .02" thick (too thin to tap into).

Water is a needless percaution. I've drilled holes in plenty 'o propane tanks... heck, I've TRIED to ignight propane [torches] with the sparks inside cutting tools and with sparks generated by cutting.
I say that, so long as you keep the tools of the cutting (as opposed to grinding) methology, you are quite safe.

[dinsdale]

Thanks, I figured it would be fine, but just wanted another opinion

[SpudStuff]

90 psi max though.

[frankrede]

I'm sure it can go higher.
As a metetr of fact I would feel safe at 130.

[frankrede]

Why would you want to put the shraeder through the back?
Personaly, I'd use the back as a stock, although I admit it's not terribly good for that job as far as ergeromics go.

I'd put the shraeder through the "top", next to the outlet. (you'll need to use one of the clamp-style ones, as the walls are only an estimated .02" thick (too thin to tap into).

Water is a needless percaution. I've drilled holes in plenty 'o propane tanks... heck, I've TRIED to ignight propane [torches] with the sparks inside cutting tools and with sparks generated by cutting.
I say that, so long as you keep the tools of the cutting (as opposed to grinding) methology, you are quite safe.

The clamp ins are the best way to go. I have a question, Wouldnt the vave on the head of the propane tank constrict flow?

[sgort87]

90 psi max though.

And what is your reasoning behind that?

And now why are we putting a shrader on the top? What good will that do? I say put a propan cyllinder to npt adapter on there and go to a blowgun.

[killagorrila99]

I'm pretty sure that I have seen this done before. Exept the propane cylinder was an air tank for a pneumatic. Looked awsome.

[MrCrowley]

90psi wtf?my blow gun says 90psi max yet i take it higher;
it should easily hold 130, At a temperature of 70° F, propane's vapor pressure is 124 PSI.It would seem that propane tanks are built to withstand at least 250 PSI. I think it logical to assume that any propane cylinder you are likely to encounter can withstand at least 200 PSI virtually indefinitely. and propane tanks have to be witdthstand pressure twice their recomendation and one in every 500 can widthstand four times more or about 800-900psi.but i doubt you would want to buy 500bottles and test them all