I now have an Aileron done and a flap done. They are internally primed where the ribs meet the skin. I followed the instructions and Evans instructions to not rivet the front three rows until after mounting them on the wing. And I’m glad I did because getting the aileron and flap and wing to line correctly on the back side took a little bit of work. My process was to mount them and then use a laser level to make sure that they were straight going across. I would hold the flap up and twist it slightly until it was straight with the laser level and then take some painter’s tape and put across the front edge to temporarily hold it in place. I had to use tape because cleco’s would stick out and not allow the flap to move. Then after I got the flap straight I did the same thing to the aileron. Using tape to hold the front down and in place. I found it necessary to use tape because I could only put the rivets in when the flap and aileron were hanging down and I can only tell if they are aligned if they are up or straight out. So had to find a way of temporarily holding them until I could rivet them. Then I riveted from the center working between left and right and outwards.
I took a picture of the laser level on aiming at the wing. Sorry I couldn’t take a picture of the holding the flap and the aileron up at the same time has taken a picture.
I’m very pleased with the results the trailing edge looks very level and uniform.