At 10:22 PM 2002-11-03 -0800, Thomas Miller wrote:
>Why go thru the fuss of weather balloons? Cheap plastic grabage bags tied
>together will lift a wire in light winds. You never knows what will work
>untill you have 3/4 tank of helium left over from a party.
>
>Tom AC5TM
I think that almost anything would work, how about a dozen condoms?
The main point is that the helium has to stay in the vessel. Some plastics
do not hold the helium which is a small size molecule. The only reason
that I know this is that we use to sell very high purity metals. To
package them so that they would not oxidize we had to have a special
plastice bag, usually with a thin metal film on the outside, then place the
metal therein, fill with hydrogen, evacuate (purge air out) then fill
again. Once we had bags that didnot hold the H to long. Boy did we have
complaints.
I like the bag with propane in. Another that was done around here was a
hot air ballon, a paper bag upside down with string holding a a lite
candle. Alright in the winter but not a good idea in the summer with dry
forests. Real sight to see. Add some flamable to the bag and a fuse then
it just might be the same as the ballon with propane.
Chris opr VE7HCB
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