## Re: [hobbicast] Re: Heavy Theory--gas pressure debate etc.

Expand Messages
• Critical limits as per BOC s manual say it will need atleast 4.1% hydrogen to air to combust. Above 75% it will not burn. John ...
Message 1 of 18 , Jul 2, 2001
Critical limits as per BOC's manual say it will need atleast 4.1% hydrogen
to air to combust. Above 75% it will not burn.

John

> aluminum foil into it into the lye. then put a balloon
> > over the end and watch it fill up with hydrogen which
> > is half the weight (twice the lifting force) of
> > helium.
> AND WILL EXPLODE ALSO where helium will not. Ask the Germans
> Larry Jackman
>
> http://budgetcastingsupply.com/
>
> The Home Foundrymen's Association website may be found here:
http://members.nbci.com/HWilkinson/
> It includes member project pages & links
>
> To unsubscribe from this group, send an email to:
> hobbicast-unsubscribe@egroups.com
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
• ... Half the weight but not twice the lifting force. You have to compair the density of hydrogen to air and the densety of helium to air. John Grant
Message 2 of 18 , Jul 2, 2001
LLandstrom wrote:

> Why mess around with helium. Get a glass bottle, fill
> it halfway up with lye, stuff some crumpled up
> aluminum foil into it into the lye. then put a balloon
> over the end and watch it fill up with hydrogen which
> is half the weight (twice the lifting force) of
> helium.

Half the weight but not twice the lifting force.
You have to compair the density of hydrogen to air and the densety of helium to air.

John Grant
• ... Yep. We used to do that when I was a kid - lye, aluminum foil, in a bottle - but we screwed the top on and waited for it to explode. We weren t very bright
Message 3 of 18 , Jul 2, 2001
> This might sound dumb but... lye?
>
> John

Yep. We used to do that when I was a kid - lye, aluminum foil, in a
bottle - but we screwed the top on and waited for it to explode. We
weren't very bright - weren't doing it for scientific reasons. None of
them exploded, though (I guess the cap leaked), except once when a
friend kicked the loaded jar in digust and was lucky not to get hurt.

Doc
• It s about 1/4th the atomic weight but it s a double molecule so it s really 1/2 the weight. LL __________________________________________________ Do You
Message 4 of 18 , Jul 2, 2001
It's about 1/4th the atomic weight but it's a double
molecule so it's really 1/2 the weight.

LL

__________________________________________________
Do You Yahoo!?
Get personalized email addresses from Yahoo! Mail
http://personal.mail.yahoo.com/
Your message has been successfully submitted and would be delivered to recipients shortly.