We spent several hours test dimpling, countersinking and riveting to get the depth of these countersinks just right. Armed with some calipers, we were able to measure the depth of the 3/32″ countersinks, and aimed for .005″ below flush (as measured with a rivet in the hole). There’s a lot of variation just from pressure on the drill, and settled for .0050″-.0065″ below flush. There are hundreds and hundreds of holes to countersink. We also riveted in the nutplates and started countersinking the #8 holes using Van’s recommended method of centering the bit in the nutplate. It started out looking absolutely terrible, but once we got the depth right it was fine.
Berck: 9 hours, Randy: 6 hours, Jonah: 3 hours