[quote name='Dad3353' timestamp='1457644217' post='3000656']
Ah..! Innovation time..! Just before sealing up the cab, how about leaving inside it a cubic centimetre of solidified helium (very low temperature required, I know, but read on...). Once hermetically sealed, the ambient temperature would cause the block of helium to melt, then evaporate, thus filling the cab with helium gas..! For a lighter still build, just double up on the helium blocks..! Then the cabs would truly become lighter, no..? No, no, don't thank me; it's enough reward to think that I've helped so many deserving folks. Well, OK then, but only small monetary donations, please; by Paypal 'gift'. Cheers.
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But if it's hermetically sealed won't the helium turning to gas blow the cone out? Mid you I guess that would still make it lighter. Attaching helium balloons (available from all good street vendors) might be a better alternative. Just remember not to tie the balloons to the handles!