: What is the most structural fiber orientation?

: When I glassed my North Star I made sure the fibers ran straight down the
: keel and deck centerline. But I questioned if it would be better to run
: the fibers at a 45 degree angle to the longtitudinal axis thus providing
: more torsional strength. It seems there is more strength longtitudinally
: inherent to the design. I am not an engineer though. Maybe two layers of
: glass, one at a 45 degree angle to the other?

: I am starting to strip a Guillemot Expedition.

: Doug K.

There isn't any significant torsional loading on a kayak, the biggest loads are longitudinal from waves or loads from either riding on or being secured on a roof rack, and the transverse loads from when you put your weight on the back of the coaming when you climb in. There can be an advantage in orienting the fibers on a bias to fore and aft in getting the cloth to lie well, but in order to get 45 degrees, you'd need some very wide cloth. I just finished cutting the cloth for 8 layers out of a 60" roll on as much bias as I could manage for a 17 foot hull, and it was more than sufficient for the outside. I haven't done the inside yet but I think it will be fine. This is satin glass, which I had not worked with before so I wasn't sure how it would behave. For standard weave, the bias you get from a 38" roll is enough.