I spent an hour or so sanding the blade of the yuloh. Where it had been reinforced with fibreglass there were irregularities. The surface was pitted and uneven. I shall not be able to remove these flaws entirely, but when I’ve finished, the yuloh will look better and it may function better because of being smoother and more correctly shaped for hydrodynamic lift. The curved surface has to be on the forward side of the blade, and the flat or slightly concave surface has to be on the aft, upper facing surface.