I match drilled the rudder stiffeners with a #41 reamer. I disassembled them and deburred the rivet holes on the stiffeners. I also deburred the edges with a edge deburring tool.
I wanted to get the rudder skin assembled, so I decided to rattle can prime the stiffeners. I scuffed with a red scotchbrite pad, washed off the part with dishwashing soap, rinsed, blew dry with air, then I dimpled the rivet holes and did a final cleaning with laquor thinner.
I was careful to do the left and right sets in two batches so I wouldn't get them mixed up.
