Sigg bottle questions.

[POLAND_SPUD]

@freddy
so you're saying that it's a hose barb (or whatever you call that thing) ?
if so then it's hammered into it... it isn't the way things should be done - that's a ticking time bomb

sure it won't blow up with a regular combustion but I wouldn't risk using it with anything else

[Freddy4130]

There isn't a "right fitting".

It's a drink bottle, not a pressure vessel. It's not designed to be compatible with airlines or pressure water systems. It wasn't made with the intention f holding pressure.

To think that the fitting is the right one and they are a perfect pressure vessel is the wrong fitting. The bottle is made to hold a few " of H2O of pressure, not 120 psi. The aluminum is thin, and it will be made from an alloy that is cheap and easy for them to work.

If you want to test it, great. If your happy with it and want to use it, great. Don't assume it was intended for this though.

I think you guys are missing the boat. I never used the word perfect at all. And Sigg bottles are clearly not created to serve the purpose of launching a potato. But then again neither is ANY other material used in ANY potato cannon that ANY person on this forum has ever built. Soooo, o think it's safe to say that sometimes we can and often do use things for purposes other than those which the product was created.

[Heimo]

@freddy
so you're saying that it's a hose barb (or whatever you call that thing) ?
if so then it's hammered into it... it isn't the way things should be done - that's a ticking time bomb

sure it won't blow up with a regular combustion but I wouldn't risk using it with anything else

It is screwed in not hammered in

[john bunsenburner]

I think you guys are missing the boat. I never used the word perfect at all. And Sigg bottles are clearly not created to serve the purpose of launching a potato. But then again neither is ANY other material used in ANY potato cannon that ANY person on this forum has ever built. Soooo, o think it's safe to say that sometimes we can and often do use things for purposes other than those which the product was created.

Think again mate, how many people here use machined parts made only for the purpose? Or a variety of fittings, valves and so on, comecially availavle, all made for the purpose they are used for here. Don't say something before thinking it through, it'll spare you a lot of dismay in life!

As for the bottel, unless you re-inforce it with molten metal, and then re make threads and the like i wouldn't trust it past the 100psi mark. But hell if you are so convinced it works, fill her up with water and pump some air in, leave it that way and if it is still full and in one piece the next day you can go ahead and assume it will not burst or deform at that pressure. Or just use it for low pressure stuff.

[Freddy4130]

Slow down turbo. You telling me there is a PVC manufacturer that suggests exploding gas inside their products? Or a propane tank manufacturer that makes products specifically made to launch projectiles from makeshift cannons? Dont be silly.

And no. I never hammered a hose adapter into a water bottle. It has threads. The correct ones. Clearly the part was made for a garden hose but it fits the bottle just like it fits the garden hose. And just like the garden hose, you need a gasket of sorts to make it seal perfectly.

I thought it was clear I was using this thing for a combustion chamber on a small cannon so I'm not sure where all the psi and "airtight" hate is coming from. If the adapter blow. Out befor the projectile then I've done something way more wrong than choosing an aluminum bottle.

[POLAND_SPUD]

well quite a lot of things were designed to hold pressure... pipes & fittings both PVC and metal, fire extinguishers etc. but this thing probably wasn't

so yeah it might be good enough for combustions but I wouldn't feel safe using it... even at 80 psi
try to emphasise that in your post... so it would be clear to anyone reading it that it might not be the best idea to use it with pneumatics

I've been looking for something similar myslef (compact large volume chamber that's rated high) but that clearly doesn't fit that criteria

empty 88g CO2 capsules are almost ideal but their internal volume is a bit too small (~110 ccm IIRC)

[Freddy4130]

I think we should reserve judgement on pressure ratings until it's been tested. Like I said before, a shaken soda (12 oz can) can produce 100 psi at temps above 90. There is no way in heck that this bottle can't withstand pressures from a hot shaken soda. Their website clearly states that soda is safe to use in the bottle.

[john bunsenburner]

Have you ever dropped a bear can on a rock or something? Well if not it shreds open, and thats with a fraction of the power in it(as liquids don't compress). Now if i can tell you one thing about you bottle for sure its that if it blows while in your hand it won't be a pretty sight, do you REALLY want to take that risk because the guy who made it says it'll hold warm coke? I wouldn't, test it and don't argue with us until you did, and until you documented it.

[Freddy4130]

Awesome. "liquids don't compress." so what about the gases inside the beer can? Does it not count in "I'm always right" world? Relax. I'm not using the thing under constant pressure. Still. And since when does a pressure rating not count just because it is a soda can or beer can? If the soda can is rated at higher than 100 psi then who cares if it's soda or compressed air? It's still rated at over 100 psi.

[john bunsenburner]

Look mate, in a soda can with beer the amount of compressed gas(=stored energy) is far smaller than in a can with only compressed gas. Now if the first one bursts then you get wet, if the second one does you can pull shrapnel out of your hand. Say you drop it, or the metal simply fatigues. You might forget to discharge it one night, ect. ect. 99 times in 100 nothing will happen, but that one time is enough to seriously hurt you. We'v had broken jaws from mal functioning pump check valves here, and an eye that was repositioned, becuase someone looked down the barrel. Carelessness can get you into deep trouble, and if spending a few more bucks on a pressure rated piece of pipe is what it takes to be on the safe side then its worth it, atleast to me.

[Freddy4130]

I'm not sure why you're so into this about psi and disharging pneumatic cannons. I believe that reading comprehension has dealt a devestatinv blow tou your dome. Nobody but you is talking about this for pneumatic purposes. Like I said, if the bottle fails before the 1/2 piece of frozen carrot is forced out of the barrel ghennive done something terribly wrong.

I currently have calls in to sigg and a local can mnufacturer here in Birmingham called Rexam. I'm sure I'll put an end to all this before the end of the day. I do appreciate your concern though. BTW, 100 psi is 100 psi regardless if the bottle is half full with liquid or all the way full of gas. Just lke a pound of feathers weighs the same as a pound of lead.

[POLAND_SPUD]

Just like a pound of feathers weighs the same as a pound of lead

lol so what would you like to have dropped on your foot ? a pound of lead or a pound of feathers?

lol I know.... smartass answer but it pretty much explains that

100 psi is 100 psi regardless if the bottle is half full with liquid

is just one of those things that are not as simple as they seem

I'm sure I'll put an end to all this before the end of the day

their answer will probably something along the lines of 'no it can't be pressurised' they might tell you you can use it for soda drinks but I doubt they'll tell you 'yeah it's pressure rated to 70 psi'

I really don't know why you take it personally...
nice find BTW and yeah I know you've said it's for combustions

[Freddy4130]

So, a quality control guy from Rexam said the tops of the soda cans are rated for 90 psi. So the weakest part of a soda can is rated for 90 psi. I think the Sigg bottle is safe for a combustion cannon.

[MrCrowley]

Apparently IIRC Aluminum got this property that it becomes more ductile at cryogenic temps instead of brittle like lots of other things.


Ooh just checked, seems I am correct

Below zero, most aluminum alloys show little change in properties; yield and tensile strengths may increase; elongation may decrease slightly; impact strength remains approximately constant. Consequently, aluminum is useful material for many low-temperature applications.

from http://www.keytometals.com/Article23.htm

PS. I am not implying that using one of these containers would be safe at high pressure

Perhaps you're not correct in this case...

Ice Cubes?:Yes, you can put ice, crushed ice and ice cubes in your SIGG - BUT DO NOT PUT THE SIGG IN THE FREEZER AND DO NOT ALLOW any beverage inside the SIGG bottle to FREEZE. The beverage will expand and crack open the SIGG bottle (much like a can of soda in a freezer). Do not leave it in your car out in the cold if it will freeze. Do not put it in your refrigerator if your refrigerator has been known to freeze items. We cannot replace bottles that have been damaged due to freezing no matter the circumstances. This is the only way a SIGG will crack open

You mix cold temperatures with pressure and it will crack.

edit:

Ok to sort this mess out...

Fill the bottle with water, hook it up to a compressor or a footpump, cover it in some heavy clothing and items, make sure you will be safe if the bottle fails, pump to 100PSI, leave it over night and yeah...

[POLAND_SPUD]

BUT DO NOT PUT THE SIGG IN THE FREEZER AND DO NOT ALLOW any beverage inside the SIGG bottle to FREEZE. The beverage will expand and crack open the SIGG bottle (much like a can of soda in a freezer)

I don't think it's exactly the same as what he meant... that effect can crack open much stronger vessels