Machine c-sink previously drilled holes to accept dimples from gap seal.
The plans call for tapping the longerons for the 6-32 screws that secure the gap seal. I tapped one of the holes and am not satisfied with the potential longevity of the threads, as there are not many of them in the aluminum and the attachment screws are steel. I am going to use the click bond nut plate that I have left over from the wing tips. These should provide a much better solution.
