printer2 wrote:
"...try to shoot for the same stiffness and weight as a wood top."
The problem is that CF composite is much denser than wood, and has a much higher Young's modulus. A sheet of CF that has the same weight as a wood top will be too thin to be very stiff, and one that is thick enough to have the same stiffness will be too heavy.
Back in the '70s some folks at the Catgut Acoustical Society worked out a spruce substitute using CF. After some experimentation they found that thin layers (around .002" or less) of unidirectional pre-preg tape on a cardboard substrate about 1/16" thick made a good substitute. They ran into two problems:
1) with changes in humidity the cardboard would swell and shrink, but not the CF. Eventually (a few months) the CF would delaminate and come off in ribbons, and
2) Kaman (of Ovation guitars) was following along on their research, and took out a patent before they could publish. They consulted a lawyer, who said they had an excellent case if they decided to sue, but that it would cost them a lot of money. Since they only wanted to publish a paper they opted not to. By now the patent has expired, so I think you could go ahead and try to solve the delamination issue. Maybe Nomex?
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