Funky place to store your fuel?

Hi all...

Was doing a little web reading on part 103 Ultralights (both gyro's and more
conventional winged thingys).....

And it quickly becomes obvious that staying under that 250 pound or so limit
aint easy...

So, so the gas tanks (like everything else on an ultralight) doesn' t really
inspire confidence from a strength point of view.....and those extra pounds to
make the tank to hold the gas are just that many more pounds you have to give
up somewhere else.

And I've notice that some gyro's and other ultralights have relatively large
hollow metal tubes that form a "backbone" to which all the other important
parts are attached....

So, my question is......could you actually USE these tubes as your gas tank to
hold your precious 5 gallons of fuel (part 103 limit)?

Anybody anywhere tried that that you know of?

Could you prevent internal corrosion in aluminum (or even steel) tubing? With
perhaps some sacrificial internal metal ( like the zinc blocks they put on
boats). And maybe make sure there is NO place for water to seperate out and
settle, or if there is, its at a place of minimal stress on the structure, or
perhaps is even a little seperate offshoot "tube" that is not load bearing in
any fashion.

Flame away

take care

Blll