Foam Core Experiment
When you're working on reducing weight, it's hard to find a lighter
core material than foam. For this experiment I'm using Rohacell 51,
a polymethacrylamide (PMI) foam that weighs in at 3.2 pounds per
cubic foot.
2.9 oz/yd udcf over foam core, no microballoons.
Finished product weighs in at 9.3 grams. Good stiffness, torsional rigidity adequate.