Guys, Hi.
1. Carbon Fiber is conductive. Where was it said that "static issues" would be inherent to carbon fiber tanks? They are completely conductive.......just like aluminum! (some might argue that the resin finish could act as an insulator) edit: why would regular fiberglass be better? regular fiberglass IS NON_conductive.
2. weight of regular fiberglass vs. carbon: Carbon fiber cloth is often used in a layup EXACTLY like regular fiberglass cloth. If one uses the same weight carbon cloth substituted in place of regular glass.......you will get the same weight layup........but the carbon one will be much, much stiffer! (conversely, if you substitute a properly designed carbon structure for a regular fiberglass structure of the same strength.........the carbon structure will weigh less!!) (Also, it has been said that a properly-designed carbon structure will save roughly HALF the weight of an aluminum structure. But this does not translate or transfer to all kinds of structures)
3. The issue with LEAKS: leaks and pinholes in composite structures often show up in open, hand lay-ups. As SpainCub said, vacuum bagging the laminate will help, as the vacuum compresses the laminate and evacuates air bubbles............but one must not have a 'resin-starved' or 'dry' layup before the vaccuum process, or leaks could occur........which brings us to #4.
4. resin-starved layups: carbon fiber is black and opaque when dry and also when wetted-out with resin. Regular glass cloth changes from white when dry to transluscent or even perfectly clear(!) when wet-out with resin. It is easy to tell a perfectly wet-out regular glass cloth laminate. It is not so easy to know when carbon cloth is properly wet-out.
5. resin: Definitely use the right resin for fuel tanks.
6. Science: This is not rocket science! or is it???
I think it is cool that your kids are involved in this project and are pushing the envelope.