Fiber orientation on hull?

[bntii]

I am laying up some 1708 biax on a sailboat hull. Long story but for a repair the hull will get 100% coverage of one layer.
I want to buy all the hull stiffening I can out of the fabric & am guessing that 45 degree fiber orientation from sheer is about right. This sound correct?

Thanks

[JR-Shine]

If you want all the stiffness you can get from equal weight, then drop the 1708 and use 2 layers of 12 oz biax. Same total weight in glass, but its 100% directional glass. the mat does very little for stiffness and will only waste resin. I am assuming your using epoxy, otherwise mat may be necessary.

This would also allow you to go one layer 0/90 then the other 45/45 - now you have bias and double-bias :)

[adamfocht]

Vectorply offers some very nice quad ax materials. They aren't like the tri-ax of old that were like wetting out carpet, they wet out very well and they offer them in different weights in each of the sewn directions.