Once the rudder leading edges had been formed with a radius, I bent the edge of one of the skins slightly using a flanging tool. The purpose of the slight edge on one of the skins is to improve the joint at the leading edge where both skins overlap. Using the flanging tool took a bit of practice to get the edge "just right". If the flanging tool slips off the edge of the aluminum, it will bend unevenly. This happened and I had to work the edge to get it with a consistent amount of bend. After I was satisfied with the flanged edge, I clecoed the rudder skins into place on the rudder frame.