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TopBand: Re: Edmund balloons; questions

To: <topband@contesting.com>
Subject: TopBand: Re: Edmund balloons; questions
From: dfi@cyberhighway.net (Scott Cowling)
Date: Fri, 27 Dec 1996 12:15:00 -0700 (MST)
Bill,

Hydrogen has approximately twice the lifting power of He.  Hydrogen has an
atomic weight of approximately 1, while He has an atomic weight of about 4.
However, hydrogen forms diatomic bonds to become H2 molecules with a
molecular weight of about 2.

The rule of thumb I use for He is one cu ft lifts approx 1 oz.  H2 would
lift approx 2 oz per cu ft.  I priced Hydrogen in 250 cu ft cylinders in
Mesa, AZ and the price is comparable.  I was concerned with 4 possible problems:

Storage:  How will a cylinder of H2 store in my shop at 120 deg F?

Handling: VERY explosive.  If the balloon blows up after launch, not much
chance of injury, just nuisance.  But what if it blows up while you are
filling it?

Affinity for rubber:  I have heard that H2 reacts with some kinds of rubber,
requiring special valves, seals, etc.  Since I wanted my balloon to stay up
for several days and it is a rubber material, I wanted to be sure.

Leakage:  Since the H2 molecule is smaller than He, I figured I would get
more leakage through the balloon membrane.

Hope this helps some.  

73,
Scotty WA2DFI


At 12:41 12/27/96 EST, you wrote:
>Anyone out there have information on the lifting power of Hydrogen. vs
>Helium,?  Anyone out there using it?  I see no problem with the antenna
>coming down, other than the labor of putting it back up again. Out here,
>there is nothing but jack rabbits, coyotes and rattle snakes.
>
>72's
>Bill  W7KXB
>near Mesa, Az.


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