I've long been curious about this idle question about fillets, and a recent post got me thinking about fillets, so I'll ask. (It is of no practical importance to me, as I don't care about extreme light weight, and all my fillets are finished, anyway.)
It is simply this: could fillets be made smaller radius, and thus lighter, if one used glass cut on a bias?
If my facts are right about why fillets are there to begin with, and why they musn't be made too small of a radius, you will understand why I ask this question. The minimum radius of curvature for the glass fibers would be greater for a given fillet radius, and thus the minimum acceptable fillet radius would be smaller, as all of the threads would be traversing the fillet on the diagonal, instead of the tranverse threads being normal to the length of the fillet.
If the logic is correct, then the question is, would the improvement be big enough--say a few ounces or more--that an extreme builder (racing kayak) would care?
Just something to noodle on. Also, maybe there's a concept in there that would apply to some more practical application.