SpudFiles

I'm sure many of you have seen these aluminum water bottles around.



I was wondering what your thoughts are on the use of one of these as an air chamber in a pneumatic. What kind of pressure do you think it could hold? I looked around a bit and tried to find some more technical information on them, but couldn't really find much at all. The few relevant things I found were on wikipedia.

Bottlecans are made from 100 percent recyclable aluminium through either an extrusion or Coil to Can (C2C) process to a wide range of shapes and sizes. Impact extruded bottles are produced with three times the aluminium of a traditional beer can, which provides for increased insulation. C2C bottles use 30%-40% to less aluminium than impact extruded aluminium bottles.

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Other than that, they are about about the same size as a 20floz sports drink bottle (~7in tall, ~3in diameter) and have what looks like to me may be 3/4" NPT threads for the screw IN (not ON) top.

I understand these would be very unsafe to use for high pressures (and understand that "high pressure" may be relative, it may not be "completely safe" at all, and that these were not designed for anything like this so there may be no pressure rating/safety factor) but it seems like they would at least be a better option than the PET soda bottles I've seen people use.

I dont know exact pressure but if you look around the forums youll see some guns using alulminum bottles as tanks, I think they came from spray bottles

some one should pressure test one... see when it fails....

.. TO THE LABORATORY!

EDIT:

Plastic soda bottles pop at around 200-300 psi.

Now i just need to figure out how to test an aluminum bottle.....

Some soda bottles burst at as low as 150 PSI and Id rather have a soda bottle blow up on me than a aluminum bottle with metal shrapnal

some one should pressure test one... see when it fails....

.. TO THE LABORATORY!

good thinking but there are different types of them so their burst pressure can probably vary a lot

I wouldn't use them. They're not designed to hold pressure. The threads aren't designed correctly, the bottle itself isn't designed correctly, and the metal used is cheap.

My suggestion is aluminum tanks designed to hold pressure. I posted a thread about making an order of these a while ago: http://www.spudfiles.com/forums/light-a ... 20352.html

clemsonguy1125, aluminum, especially in a bottle, is far more likely to tear and leak out the tear than create shrapnel. Aluminum is a ductile material. PVC is relatively brittle. The two are not comparable.

Any links clemsonguy? I've seen some that use aluminum tanks or other repurposed aluminum, but not any like this. Somebody even posted a link to a "light air tank" I think they called it that someone had constructed out of aluminum soda cans and some sort of epoxy. If I recall correctly he took it up to a decent pressure. These bottles seem to be a good bit thicker than soda cans.

I wish I had the time or the resources to do some significant testing on these things.(I'm actually an engineering student as Clemson University :thumbleft: )

Id rather have a soda bottle blow up on me than a aluminum bottle with metal shrapnal

That's one thing I was wondering about, I'm not so sure it would fail in the same way as those bottles. And it seems to me most definitely not in the same way as PVC would.

EDIT: I type too slow, you guys are ahead of me.

I wouldn't use them. They're not designed to hold pressure. The threads aren't designed correctly, the bottle itself isn't designed correctly, and the metal used is cheap.

My suggestion is aluminum tanks designed to hold pressure. I posted a thread about making an order of these a while ago: http://www.spudfiles.com/forums/light-a ... 20352.html

True, all the one's I've seen have only had like 2 wraps of the threading on the female bottle thread. Would it be too hard to reinforce it with something though? Maybe a bulkhead fitting and some o-rings or something?

I once pressure tested one of those super thick soda cans that all the new energy drinks are coming in. It was a "Venom" (I didn't drink it, it was a friend of mine. I can't stand the taste)
I got up to at least 130psi (I don't remember exactly) before the cap blew off. I couldn't see if there was any deformation under pressure, because I was hiding behind a refrigerator, in case it went boom. Still, the super thin aluminum cap held it to 130+psi, and the bottle is many many times thicker than the cap.

Just my slightly unrelated 2c.

well there are good bottles only they dint and scratch really easy your far better of stealing or buying a fire extinguisher like $20-40