Finished conversion coating the VS skin. Applied Sanchem Sealer #2 to the substructure except for the rear spar and top rib pieces. Decided to prime the rear spar and top rib with AKZO Epoxy primer as they will be externally exposed. I decided to leave the rear half of the top side of the top rib unprimed as I plan to bond a fiberglass filler piece to this to finish off the top rib. Not sure exactly how I will do this, could be fiberglass covered foam or an aluminum piece held in place with rivnuts. This will smooth the airflow in this area and keep water out of the vertical stabilizer too. In any case, I can always prime later if I want to.