There seems to be as many opinions on primer as there are builders. Given that 6061-T6 is inherently corrosion resistant I reason that any primer made for aluminum and properly applied will add an extra margin of useful life. In my quest to keep my project simple without compromising integrity I chose Rust-Oleum Professional Alumium Primer for my rudder. When I get an in-line air dryer for my compressor I'm going to try Rustoleum Clean Metal Primer that was recommended by Dave Clay who claims it adheres very well.
In the event I decide to polish my plane I masked off the surfaces that will be exposed and primed all the other surfaces.
I pulled my first A4 rivets by joining the doublers to the spar. If only the rest of the scatch building could be this simple, fast and fun!
