About fiberglass splices.
Payson and Carnell miss an important point. They use plain woven glass
in which half of the fibers run paralell to the seam: a complete waste
of glass and resin.
The proper way to build such a seam is with biaxial 45/45. With that
type of glass, all the fibers work and it also adds a little torsional
strength.
I don't know why that point is not understood. I mentioned it for the
1st time here 12 years ago and designers still specify the wrong type
of glass for splices and stitch and glue seams.

Jacques from bateau.com