We then decided to brace the aileron with a framework to help alleviate and bending while riveting. We suspect that the forces placed on the aileron while trying to buck is bending/tipping the aileron enough to affect how straight the rivet is with the bucking bar.
The frame work certainly helps a lot, rivets went together nice and straight. However we found towards the middle of the aileron the there is a tendency again for the rivets to slump. So, we decided to back rivet these with a C-frame rivet set and mike on the bucking bar on the exposed side. We did a partial set of the rivet and then switched back to the bucking bar inside and rivet gun outside with the flush set to complete the rivet buck. Worked like a charm. I am very satisfied with the result. Very good rivets.
I am all ready for pre-close inspection