I continued working on the empennage by adding C75F6-6 (stiffener) to the vertical Side Channels and then riveted the top channel and doublers together. I did make a mistake and riveted the top doubler to the top channel with A5s. I had to drill them out and swap them with the correct A6 Riviets. between all mating parts I continued to prime the metal parts. I swapped to Krylon Self Etching.