Isn't H2 better because better lift and being a molecule of two hydrogen atoms it is not quite as slippery as helium and quite easy to make? From wikipedia "lifting gas" "Helium is the second lightest gas (0.1786 g/L, 14% the density of air, at STP). For that reason, it is an attractive gas for lifting as well. A major advantage is that this gas is noncombustible. But the use of helium has some disadvantages, too: Th…
The diffusion is the main advantage of using helium, it takes ~3x longer to leak out, which directly affects flight time. Hydrogen is actually harder to buy in my experience, helium is sold everywhere for cheap in small canisters for parties, whereas the second requires like, industrial welding suppliers that will want to sell you a large tank for a few thousand or making your own electrolyser and compressor. There's…
Re: High-Altitude Adventure with a DIY Pico Balloon
#61'Balloon Gas' for inflating party balloons is a mixture of Helium and Oxygen, at least in the UK, to stop Tweety Pie asphyxiating him/herself breathing the gas. So although it still is lighter than air, it's not as good as pure He.