....continued the riveting of the right wing skin .....spent some time in research of a strange phenomenon I was observing where the skin was hollowing at each rivet, I had straightened all the rib flanges in prep for riveting and had the gun and pressure set at it's lowest with the correct rivets but still got occasional hollowing.
I found this to be a symptom of a hole that was over dimpled which is understandable since I drilled for size 4 (using 'oops' rivets with the smaller head) and dimpled accordingly, I should have left it at a #3 dimple. It is confirmed as not being serious and at worst would be visiible only at extreme close scrutinizing post paint and filling. Even some rubbing with 3m pads seem,ed to remedy the look quite a bit.
I then used a very light tapping of the gun on a backplate at each hole affected to lessen the dimple slightly which seem,s to have worked.
