Brief Description: Flap - Drill rib to rear spar part 2.
The rib trailing edge does not make it all the way to the rear spar rolled in the bottom skin. The plans say to make shims. They don't specify the thickness or size. Just do you one thing here.
I made all my shims out of 0.040 stock. All the shims are 5/8" by 1/2". This 1/2" length makes them a bit long but it helps to have something to hold on to when you drill.
