Deburred all holes in "U" channels,filed edges & primed all components. Put adhesive cork on fuel tank & "U" channels to protect from contact with metal. Riveted 4-"U" channels in place on spar & rib # 1. Riveted 7-nutplates (MS21047-8/32) to the 2-"U" channels for rib #2 with AN426AD 3-3 rivets.
