If you are around any oil rigs you may be able to find some old pump rod.
This rod is fiberglass, one inch in diameter with a large metal connector on
each end. Just hack saw the ends off and you have about 20 feet of very
rigid fiberglass rod. It is easy to make booms of 6 to 8 feet with no droop
at all so a shorter boom would be even better. If you find some after you
have cut it to length give it a good coat of paint just to keep the
fiberglass slivers down.

K7SAM