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Dave, did you ever get a response from Frederich? I'm curious to know why he is now using Nomex.

Also, if most of this is about weight. Couldn't you use a drill to hollow out ever so small circles on the bottom layer and glue the top layer over this thus negating the need for both Nomex and/or a middle sandwich?

Hi Darren,

I haven't found time to email Federich yet!! I'll get onto it soon, promise!

The asymtote of what you are proposing is just taking your standard spruce top and lightening it by drilling it out in places - that doesn't work, otherwise we'd all be doing it already, right? I'm sure that it's not just low weight that we're looking for here, but high structural stiffness WITH low weight.

The honeycomb (either Nomex or little laser-cut hexagon's in a layer of spruce like I'm doing) in the center of two thin sheets of spruce produces a very rigid structure. You can consider each wall of the hexagons to be a teeny-tiny I-beam, so when you add up all the hexagons and consider that every facet is joined at 60 degrees to another section, the net result is a VERY strong structure indeed. If you leave off the bottom layer of spruce, then the teeny-tiny I-beams become severely weakened - they become "T" structures which are nowhere near as strong as I-beams.

Cheers for now,
Dave F.

_________________
Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

I've been visualizing a top plate of normal thickness and upper bout bracing as normal but with a Nomex patch as the bracing. Or even fan braces made of spruce-Nomex-spruce.