I dimpled and deburred all the stiffener holes in the rudder skins and took my file to the edges of the rudder skins to knock the burrs off the factory cut edge.
The back riveting technique was used to rivet the stiffeners to the skin. After the skins and stiffeners were all prepped i placed an AN426AD3-3 rivet in each dimpled hole in the skin. Next I used riveter tape and placed over the flush side of the rivets, this holds the rivets to the skin for the next step when flipped the skin - exterior side down on the table. This leaves the rivet posts sticking straight up and the stiffeners are then layed in their respective location. I then placed a large back riveting plate under one row of rivets and worked the shop heads from the top with a back rivet set.
This produces the fastest and best possible looking rivets. I verified the shop head of each rivet was the correct size. There was no marring on the surface either.
The rudder skin and stiffeners was a rather simple and enjoyable task however, it took quite a long time for what actually gets done.
It took an entire 8 hour day to fabricate the two skins with the stiffeners secured to the back. (this includes removing all blue plastic, deburring all parts, priming, etc.)
