This was a quick work session to prime the internal rudder parts since the next steps in the instructions would start to require parts to be riveted together. As usual, I started by roughing up all of the surfaces with scotch-brite pads and then wiping down with some acetone. After a quick spray with some self-etching primer on both sides of the parts, they were all ready for the next steps.
What's next? Start final assembly and riveting of the rudder parts to its spar.