Good evening /diy/
I have this old expired co2 tank, used for paintball, that I don't want to throw away. Have you ever done any kind of project with old tanks? Could it be strong enough to be used as a crucible, so I can melt some aluminium. I tried google, but nothing came up.
I don't intend to repressurize it, unless you tell me it would be safe to use as a mini air compressor. Not particularly useful, but why not.
well if you fill it up with CO2 again, and get a pressure regulator, you can use it to charge up a pneumatic cannon.
What do you mean by expired? Do these things only last a limited number of pressurization cycles? If so that's a horrible design and it's probably aluminum. So you won't be able to use it as a crucible for aluminum.
By expired, I mean that they don't allow tanks that are something like 2-3+years ( don't quote me on this) at my paintball field. I already have a fiber one, so I have no use for the metal tank. And just by the weight of it, it's probably not aluminium.
If it's not past it's last hydro date it can still be hydro tested and used.
Since it's a metal compressed air bottle it's very unlikely it's expired, they simply haven't been around too long in paintball.
Where I live the amount of steel tanks that don't pass because of rupturing is next to none. And tanks need to be inspected every 10 years! They always fail because of the visual inspection=rust. So basically whining about a 2 years old steel tank, if tested, is dickery. Just sayin'....
Weight alone isn't a very good indicator. Aluminum is about a third as dense as steel, but it's also about a third as strong as well. The result of this is that, for the same volume, pressure rating and safety factor, a pressure tank made of aluminum will have walls three times thicker and weigh about the same as an equivalent steel tank.
well if it is aluminum, you should be quite worried about it rupturing. Aluminum, unlike steel, has no fatigue limit. Which means no matter what repeated loading and unloading will cause it to break.
Now there is a simple test to determine if it's steel or aluminum. Just put a magnet up against it.
>And just by the weight of it, it's probably not aluminium.
Firstly, that's not a CO2 tank, that's straight compressed air.
Secondly, get it hydro-tested, and if it passes you're good to go (and make sure you get your fibre wrap tested every 5 years).
Thirdly, reg on those outputs about 800 psi, so whatever you have in mind has to be able to handle it if you're going to keep it intact.
A "mini air-compressor" won't work, it's a tank, and a tank that you'd need an expensive compressor to reach 3000 psi with. It is indeed steel though.
>Thirdly, reg on those outputs about 800 psi
You can get some that go lower, though they're harder to find. Inline regulators can be found that will get you below 100psi, but you'll likely need to also use two ASA adapters, a high pressure line, and a downstream pressure gauge (because the one included with the inline regulator doesn't have the right measurement range).