Now that the stiffeners were done on the left fuel tank, I decided to get them done on the right fuel tank too since I had the process figured out. This time I tried applying a little more sealant near the bent side of the stiffener so that there would be enough squeezed-out to avoid the need to add more sealant later. This worked better, but I still needed to a little more in a few spots. I did have to drill out and reinstall 4 rivets because they weren't flush enough--I guess I wasn't pressing down on the backriveting plate firmly enough the first time.