Inflatable filled with Helium

[PCUK]

What would be the result of inflating an inflatable with Helium. Would you be able to walk it up the pontoon like a balloon on a string. Would it perfrom better under way. WOuld it make any difference?

 

[David2452]

No, and if it sprung a leak you would be talking like a Chipmunk.

David

 

[totopalm]

I 'spect 2 Tons of ballast would help to keep it in the water

 

[Nick_H]

It takes 20 helium baloons to lift a wine glass, so filling your inflatable will make sod all difference.

 

[Strake]

Nice idea .. /forums/images/graemlins/smile.gif

Say: 3/4 man dinghy weighing 40Kilos. 1 cubic metre of Helium will lift 1Kg. If you tried hard, you could probably get 7/8 cubic metres into the dinghy...looking on the bright side, thats 8 kilos lighter but your cost/perfomance ratio at appx £10 per cubic metre might be a bit dubious. But you were only joking......
' course, you could always try Hydrogen..it's slightly more efficient and would work wonderfully with a nice sparky two-stroke.. /forums/images/graemlins/grin.gif

 

[PCUK]

So basically the tubes have got to be of much larger diameter.
I see.

 

[Bejasus]

also remembering that the 2 smallest atoms are Helium and Hydrogen, so you had better be sure that the tubes are absolutely airtight. Air on the other hand is huge in molecular comparison, so doesn't as readily leak through the fabric. It's why we use Helium to test gas lines in the oil industry. Hydrogen, although a smaller molecule would be a tad too risky. /forums/images/graemlins/laugh.gif

 

[Strake]

Nope. Larger tubes= even more weight. The tubes must be lighter. They would need to be some sort of woven Nylon reinforced with a material to stop leakage...almost like ripstop parachute fabric with a plastic liner. Nice and light..........with absolutely no damage resistance...
Best get the Admiral to carry the dinghy. Much cheaper in the long run.

 

[Dave_Snelson]

Use of Helium in sponsons is banned in ZapCat racing as it is deemed to give an unfair weight advantage over ordinary air. Samples are taken before races.

 

[PCUK]

Thanks Dave, so it does make a difference!!!

 

[Nick_H]

I'm not at all convinced. The volume of the tubes is "Pi x r squared x h". Lets say the inflatable has 40 cm dia tubes and the total length of the tube is 5 metres (on a 2,6 metre boat).

The volume is therefore 3.142 x 0.4 x 0.4 x 5 = 2.5 cubic metres of Helium. If a cubic metre of helium gives a kg of lift as someone stated above, that's 2.5 kg of lift on a boat / engine combo which must weigh something like 50 kgs.

So at cutting edge racing levels it may make a slight difference, but in general terms I stick with my scientific analysis of sod all.

 

[PCUK]

Surely sod-all is better than nothing?

 

[gtmoore]

This was on Mythbusters the other week - can you surf an aircraft raft filled with helium and just before that, do helium filled footballs travel further that air filled ones. The answer to both is pretty much 'nope'.

The previous series episodes are repeated everyday on Discovery at 6pm if anyone's interested...no, I didn't think so /forums/images/graemlins/blush.gif

Mythbusters

Gavin - (Mythbusters fan /forums/images/graemlins/grin.gif)

 

[michaelh]

Its 3.142 x 0.2 x 0.2 x 5 which =0.6285 (radius not diameter) which further confirms your scepticism.

 

[Strake]

I also think Mythbusters is an excellent program. All the things I'd love to do but can't.....including the rather "foxy chick" whose name I've forgotton.....

 

[Nick_H]

Correct, and well spotted. A lifetime subscription to all the IPC magazines on its way to you.

 

[michaelh]

Ooh! Ta

 

[Mr_Tumble]

This was on Mythbusters the other night and this thread gave me an idea.....

Cheers
/forums/images/graemlins/laugh.gif
Mr T