I should have taken care of riveting the platenuts for the access plate before back riveting the reinforcement plate on. I ended up cutting a small strip of 1/8 inch aluminum and clecoed it to the back of the reinforcement plate. I did this so that the countersink would have a sufficient pilot hole to properly countersink the thin reinforcement plate. This worked very well. Once all of the rivet holes were countersunk for the platenuts, I riveted all of the platenuts on and then realized I had used the wrong platenuts. I used the one called for in the plans but the pictures of the platenuts in the plans were different. As it turned out, I should have used the platenuts with large dimples for the screw in them. These are a different part number than what is on the plans. If you look at the second picture, the platenut on the left is what I should have used while the platenut on the right is what is actually riveted in place.
Countersinking the access plate
Oops,,,I riveted on the wrong platenuts!!! Bummer.
