What gas is everybody using?

[KI9L]

I use hydrogen, what do you use?

[EA5HAV]

Not trying to blow myself up just yet. Helium!

Err... is methane lighter than air??

[KI9L]

http://www.chem.hawaii.edu/uham/lift.html

[SpaceBalloon]

We're still flying He for the moment. Hydrogen is twice the lift and a lot less money - but legal transport of large amounts becomes a bit of an issue. And in high-static prone regions (like high deserts), ESD ignition becomes a concern. Until our static detectors prove-out, we'll run with He for the moment.

[K0BR]

Helium right now but I do have a Nomex suit and head gear for the switch to Hydrogen.

[KI9L]

We're still flying He for the moment. Hydrogen is twice the lift and a lot less money - but legal transport of large amounts becomes a bit of an issue. And in high-static prone regions (like high deserts), ESD ignition becomes a concern. Until our static detectors prove-out, we'll run with He for the moment.

Wuss

[KI9L]

Helium right now but I do have a Nomex suit and head gear for the switch to Hydrogen.

That's the spirit!

[SpaceBalloon]

Although it IS plentiful, I think I'd avoid Methane.

0.717 kg/m^3 versus 0.0899 for Hydrogen and 0.1785 for Helium. Air is 1.293kg/m^3 (all assuming 0C and 1atm - aka STP rather than NTP)


Methane is heavier than air when refrigerated. Which leads one to wonder if it wouldn't make be a [dangerous] choice for long-distance floating.

[tstowe]

Ok, let's say I use helium now. If I want to switch ot hydrogen, what do I need to know? What do I have to do differently?

[KI9L]

Well...

This is from a discussion I had earlier...
This is just the start of the discussion on using this gas. I would consider it the place to start your research to see if you feel safe with your set up.

I like Hydrogen however there are many things to consider before making use of this gas.
It is Flammable and potentially Explosive
It is Flammable and potentially Explosive
It is Flammable and potentially Explosive
It is Flammable and potentially Explosive

Now... There are really only two main conditions to worry about:
The region of the border between hydrogen and air - Fire
And a almost 50/50 mix of hydrogen and air - Explosion

Fire is mostly a concern around the nozzle and and filling hose. Also if a filled balloon catches fire it will burn not explode.
The explosion part is only a concern if there is air in the balloon before filling and it is allowed to mix.
All of these conditions require a source of ignition like a spark or flame.

For absolute safety I would go with helium.