Made a jig to hold the TE wedge for countersinking on the drill press. I have lots of hardwood flooring pieces (from doing our kitchen floor 2 years ago).When I assembled the rudder, the LE of many of the stiffeners interfered with the spar. So I got out the Dremel tool and trimmed them back. I slid a piece of aluminum (a flattened scrap stiffener piece) between the stiffener and skin (bent back the skin just enough to slip it in) to protect the skin.