Partially filled the tank with E-85 and sloshed around. Left overnight to dissolve most of the skin printing inside the tank. Drained tank and filled with straight gasoline for leak test. No leakage detected, but will test again once in bay with SkyTec fuel lines attached. Riveted the flaperon brackets after Cortec application. Started corking the fuel bay, but ran out of cork. Measured for fuel return line, but did not drill yet.