Today I completed the repair project I started yesterday. I drilled out the rivets holding the nut plates. I used a #30 drill bit to drill out the heads of the rivets. I then used a #40 drill bit in the drill press to drill the body of the rivet out of the holes in the ears of the nutplates. It was a fairly simple process. I was able to remove the nutplates without damaging or enlarging the holes in the ribs or the nutplates. Next I drilled the #19 holes where the nutplates will be attached to the correct ribs. Next I clecoed the nutplates to the ribs and proceeded to install the rivets. It was good to get that little correction made.
I also riveted the nutplates to the edge of the floor skins. There are a buzillion nutplates to be installed in this section.
I then riveted the floor skins to the floor ribs, using the LP4-3 and CS4-3 rivets called out in the instructions.
I used the 1/8" back-up washers on the ribs where I removed the nutplates. The fastener holes at each nutplate was previously drilled to #19 so it was too large for a LP4-3 rivet to work properly. With the back-up washers they worked fine.
