Back rivet for the win! I really was not found of back riveting so many AN4 rivets but after this section I consider myself to be quite the expert.

I ended up using every bucking bar I could to get to all the heads of the rivets including my tiny tungsten bucking bar which is my main bar. I used it for the 70 degree angle that allowed me to get into the center section perfectly without having any high rivets.

I ended up drilling out about 15 rivets total but I managed to do this without messing up any holes. Many of them probably did not need to be drilled out but once you established perfection on the flush head it's difficult to allow any high set rivets to stick around no matter how close to flush it may be.

A few nut plates (k1000-4) are on b/o so I wasn't able to get this completely done. But I will be able to get those done later when they come in.

For thes center section I ended up using a piece of woof between the two angles to apply pressure in the backplate. I even talked my wife into climbing up onto the workbench and placing her foot on the wood to allow me to use two hands on the rivet set.

There's actually a handful of rivets at the bottom that I was not really able to back rivet without a long back rivet set. If I had that I could have done them all, but instead I will wait for a friend tomorrow and we will just buck them with the swivel head.

The final step was to ream the 6 holes for the engine mount. I used the drill press on the work bench and placed the fwd side face down on a plywood table while I matched the drill press to make it a right angle.

Onto section 28!