I scuffed all of the stiffners in preparation for priming along with the associated inside of the skins (just along the rivet lines). I do this before I dimple as the dimples destroy the scotchbrite pads. Next I dimpled all of the skins and stiffners. Then I cleaned with acetone and then primed. I didn't prime the entire skin as there is more work to be done on it before that occurs.
