:p *TIP* Most of you have an old inner tube lying around, or can get a non-repairable one, at no cost, from a bicycle repair shop. I can list several several hobby uses of these old tubes.
1. Punch a hole and make custom washers to be used under machine screws to waterproof screw holes made in your WTC. end cap or lid.
2. Cut 1/4-1/2" cross sections and make sturdy rubber bands, useful for holding AA batteries in battery cases.
3. Cut off the valve and modify for use as a vent valve, operated by a servo wheel cam. Or use in end cap to act as pressure relief valve.
How many other uses can you think of? Does this remind you of practical uses for other easily obtainable or surplus items?
RCABS- It's easy to control your own bladder!