4 ms·

Case in point, helium filled balloons that deflate over a couple days.

by hanniabu 8y ago

yetihehe 8y ago
Air filled balloons also deflate over a couple days.
namibj 8y ago
Compare with aluminium coated foil. They don't deflate that fast.
- Keloo 8y ago
  Or intestines of cattle. https://en.wikipedia.org/wiki/Zeppelin https://en.wikipedia.org/wiki/Zeppelin Early Zeppelins used rubberised cotton for the gasbags, but most later craft used goldbeater's skin, made from the intestines of cattle
jammi 8y ago
That’s just because rubber balloons are extremely porous, especially when stretched. They don’t hold other gases well either.
- ricardobeat 8y ago
  Helium balloons are commonly made out of Mylar instead of rubber, and can keep inflated for weeks.
  - Cthulhu_ 8y ago
    The type intended for keeping around / in a shop for longer time are, but the children's party type often are inflated on the spot.
    - lb1lf 8y ago
      Completely irrelevant, yet amusing: At a former employer, we had access to what can only be described as unlimited supplies of hydrogen. This led - in addition to lots and lots of eardrum-splitting workshop pranks - the occasional kids' party balloons being inflated with hydrogen. (As it was free, which He definitely isn't. HS&E be damned.) A then colleague of mine claimed they'd cracked a window and caused instant panic at his son's birthday party when a bright spark decided to put a balloon to a lit candle to show the other kids it'd pop. I doubt the cracked window (given a standard party balloon is pretty small - and a cracked window would likely mean lots of -ahem- eardrum deficiency in the assembled crowd) - but I can imagine it got the kids' attention all right when the balloon more or less exploded. (We did crack a couple of windows in the workshop, though - you'd be amazed at the bang a litter bag filled with a hyd/ox mixture can produce if set alight.)
      - hazeii 8y ago
        Hydrogen alone just makes a soft pop; as you say, for a bang it needs to be mixed with oxygen prior to ignition. >you'd be amazed at the bang a litter bag filled with a hyd/ox mixture can produce if set alight. Try a large garbage bag with oxyacetylene mix (do not try this at home).
        Florin_Andrei 8y ago
        https://www.youtube.com/watch?v=YDls3_v_2oI https://www.youtube.com/watch?v=YDls3_v_2oI
        lb1lf 8y ago
        I guess - never having tried the party balloon trick myself - that such a small amount of hydrogen will mix well enough with the surrounding air as the balloon pops to create a (modest, at least) bang as the mix ignites, but this is just conjecture. Maybe I'll have to do some empi research one of these days - we do have a few bottles of oxygen and acetylene in the workshop at my current employer. Hey ho, time for an engineer to pay our welders a visit.
        8y ago

Case in point, helium filled balloons that deflate over a couple days.

yetihehe 8y ago

Air filled balloons also deflate over a couple days.

namibj 8y ago

Compare with aluminium coated foil. They don't deflate that fast.

Keloo 8y ago
Or intestines of cattle. https://en.wikipedia.org/wiki/Zeppelin https://en.wikipedia.org/wiki/Zeppelin Early Zeppelins used rubberised cotton for the gasbags, but most later craft used goldbeater's skin, made from the intestines of cattle

jammi 8y ago

That’s just because rubber balloons are extremely porous, especially when stretched. They don’t hold other gases well either.

ricardobeat 8y ago
Helium balloons are commonly made out of Mylar instead of rubber, and can keep inflated for weeks.
- Cthulhu_ 8y ago
  The type intended for keeping around / in a shop for longer time are, but the children's party type often are inflated on the spot.
  - lb1lf 8y ago
    Completely irrelevant, yet amusing: At a former employer, we had access to what can only be described as unlimited supplies of hydrogen. This led - in addition to lots and lots of eardrum-splitting workshop pranks - the occasional kids' party balloons being inflated with hydrogen. (As it was free, which He definitely isn't. HS&E be damned.) A then colleague of mine claimed they'd cracked a window and caused instant panic at his son's birthday party when a bright spark decided to put a balloon to a lit candle to show the other kids it'd pop. I doubt the cracked window (given a standard party balloon is pretty small - and a cracked window would likely mean lots of -ahem- eardrum deficiency in the assembled crowd) - but I can imagine it got the kids' attention all right when the balloon more or less exploded. (We did crack a couple of windows in the workshop, though - you'd be amazed at the bang a litter bag filled with a hyd/ox mixture can produce if set alight.)
    - hazeii 8y ago
      Hydrogen alone just makes a soft pop; as you say, for a bang it needs to be mixed with oxygen prior to ignition. >you'd be amazed at the bang a litter bag filled with a hyd/ox mixture can produce if set alight. Try a large garbage bag with oxyacetylene mix (do not try this at home).
      - Florin_Andrei 8y ago
        https://www.youtube.com/watch?v=YDls3_v_2oI https://www.youtube.com/watch?v=YDls3_v_2oI
      - lb1lf 8y ago
        I guess - never having tried the party balloon trick myself - that such a small amount of hydrogen will mix well enough with the surrounding air as the balloon pops to create a (modest, at least) bang as the mix ignites, but this is just conjecture. Maybe I'll have to do some empi research one of these days - we do have a few bottles of oxygen and acetylene in the workshop at my current employer. Hey ho, time for an engineer to pay our welders a visit.
        8y ago