I finished deburring the left rudder stiffeners.
I primed the parts. The skins are not shown in this picture.
I started back riveting the stiffeners to the skin.
While I was back riveting, I mistakenly tried to set a rivet that was not supported by my backing plate. My rivet set deformed the skin in a nasty way. The root of the problem was the backing plate I was using–it was way too small. This was caused by riveting against a back plate that was too small. I tried to fix the problem, but the material looked progressively worse. I’m going to have to buy a new left skin and stiffeners. 