I finally received the tool I needed to create the stiffener ring around the lightening hole in my custom-made F-810A aft fuselage bulkhead. (It's a Hole Flanging Tool, sold by Avery.)
In no time, I'd created the stiffener ring in the bulkhead, which removed all the oil-canning I'd experienced before. I'm going to call this particular project complete -- and a complete success!
