There were a few holes in locations not ideal for dimpling. If you have a hole that is close to the edge of the flange, dimpling can make matters worse by not allowing the joint to come together all the way or stress cracking flange. In those locations, I choose to machine counter sink the holes in the skin with a micro-stop instead of dimpling. I covered those holes with these orange dots so I would not accidently dimple them in the heat of the moment. This was five holes total. Two on each side of the root rib, (they were fine, the bend of the airfoil was not I deal for a dimpled joint) and one a rib where I had an elongated hole in the flange. It was just one, so….. I did a wet install with Pro-seal and slightly over drove the rivet to fill the hole. (then tried to forget about it!)
I also found that a cold skin did not dimple as well as a warm one. So before dimpling, I apply a little heat with the gun. Not too hot, just cozy! A little above room temp is all it takes. The dimple seems to be just a little crisper, with less collateral concaving on the skin around the dimple in between holes.
Maybe I am just going crazy, but the dimples seemed to look better.
