I put the final rivets in the aileron skin to rib at the trailing edge. The clearance there is about 1/4 inch. I used the custom 1/4 inch bucking bar I made earlier (see tools) and was able to get two flush rivets in on top. But there was not enough clearance to get the two bottom rivets in. I forced them and cracked the shop heads. In future if I see this situation again I will use a flush pulled rivet. Trying to smash a flush rivet only dented up my skin.
