Before riveting the skin to the bottom of the frame I realized the rib flanges needed to be reprimed, which I did with spray primer. Since these have to dry before attaching the skin I also decided to go ahead brush prime the heads and blind sides of all the rivets in the frame - excluding the heads on the rear web which may get polished. This addded protection will provide piece of mind that these uninspectable joints will stay corrosion free for a long time.
