The rudder skin is very thin compared to the skins on the horizontal and vertical stabilizers. So care needs to be taken when deburring the holes, below I have enlarged the holes for the stiffeners to #40 and in the process of deburring both sides, top and bottom, left and right skins.
After the holes have been deburred, I took some red Scotch-Brite and went over the row where the stiffeners will go.
Below is a close-up of the rudder skin after dimpling using the DRDT-2. The holes closest to the leading edge, I used the low profile dies that used the hand pulled rivet. I think everything has turned out well.
