I final drilled the left stiffeners and deburred the holes and skin edges. Then dimpled all the holes. It's very important to pay close attention to the orientation of the stiffeners on the skins as the stiffener flanges on the right skin sit opposite the flanges on the left. I layed the skins down bottom to bottom so the stiffeners would all go on the same direction but would be offset when the skins are put together ( see first pic ) . In the first picture the stiffener flanges ( the part that sticks up frome the skin ) on the right are on the bottom while the ones on the left are on the top.
