Aluminum water bottle air tank

[hyperspaz]

I want to use an aluminum water bottle as an air chamber, but i dont know what kind of pressures one can handle. They're pretty cheap and look fairly strong. Do you think one could safely handle 250 psi? I'd test it, but i don't have the right equipment.

If someone else were to test it, use a coleman water bottle--they have actual threads, and are only $6 on amazon.

http://www.amazon.com/Coleman-Aluminum- ... 738&sr=1-1


Let me know your thoughts on this.
thanks!

[saefroch]

Not an advisable air chamber. They are so thin that they can be dented just by falling off a table. I also doubt their threads are compatible with anything. I'd just go the route most of us do and use sch 40 pipe fittings or a fire extinguisher (or other vessel designed for very high pressures).

[Lockednloaded]

I've used a similar bottle, it hade female 3/4" GHT threads. It was easily adapted, and it held the 160 psi I regularly put in it just fine, but it got a small dent after barely being hit, so it was decommissioned. I'd recommend some sort of rigid conduit sleeve to protect it from dents

[jackssmirkingrevenge]

Not recommended for higher pressures - that flat bottom really doesn't bode well - but similar bottles have been used in the past, some examples:

"bud gun"



"bud gun 2"



"snipalux"



"onslaught"

[hyperspaz]

Thanks for your input! I found a bottle at my house that has perfect 3/4" threads. I think I'll put a couple of layers of fiberglass around it (especially the flat bottom), and only take it up to 160 psi or so.

[jackssmirkingrevenge]

It's where the bottom meets the sides that you should be concerned with.

and only take it up to 160 psi or so

Assuming the bottle is around 3 inches diameter, that gives the bottom an area of around 7 in², meaning that at 160 psi there's a force of 1120lbs trying to rip it off.

[hyperspaz]

My bottle looks to be exactly the same as the one used in the "snipalux" which was pumped up to 220 psi, so if i wrap mine in fiberglass, or even filament tape (180lb tensile str/in) I should be fine getting away with 160 psi, right? I'll pump it up from a distance the first few times before getting near it.

[ilovefire]

I'll pump it up from a distance the first few times before getting near it.

its not the first few times you should be worried about, repeated flexing of that joint will slowly weaken it, thus taking it to breaking point, im not saying it wont be able to take the 160psi im just saying you have to think about repeated stress