I bought a second hand foil and it had a minor crack around the rear wing, I sanded it down filled it with this mesh stuff and then use Araldite over it.

I sanded it down again to make it a bit smoother, my question is if I sand it down more it will remove some of the mesh. So should I leave it the way it is and if so do you this this will have an effect on the ride? Or how else should i repair it?