Match drilled all the holes in the front spar, rear spar and stiffeners up to #30, deburred all the holes and countersunk the rear spar stiffener for the flush rivets, dimpled the marked holes to match countersink 120 degree s/s rivets. Used Stewart Systems Eco-prime by dipping rivet stem prior to pulling the rivet to protect the dis-similar materials from causing corrosion - this will be the only corrosion protection to keep the weight to a minimum. Match drilled the rudder horn onto the rudder bottom rib as per plans.