I deburred the holes in the F-6111 ribs and skin. I used scotchbrite and emory cloth to edge finish and scuff the F-6111 ribs. I dimpled them with the squeezer. I scuffed the skin and dimpled it on the C-frame.
While I had the skins off I noticed the holes in the F-707 bulkhead where the skin didn't fit well had become elongated due to the force I was using to try and get the skin on. The flange is 1/2 inch wide which provides sufficient edge distance, so I decided to drill the holes up to #30 and install -4 rivet in this bulkhead. I cleco'd on both skins and drilled the holes up. I removed the skins and deburred the skins and bulkhead. Most of the holes rounded up nicely, but a couple at the bottom (near the longeron) were still ragged at #30. I plan to add a doubler here to provide a good base for these rivets.