The elevator trailing edge skins are supported by a set of pvc foam ribs that are glued to the structure. The kit provides several blocks of foam that must be shaped into the final rib shapes using templates printed in the instruction manual. I used a light mist of 3M Super 77 spray adhesive to attach the paper templates to the foam blocks. Then I used the band saw to rough cut the shapes and the stacked the ribs and used the belt sander, several sanding blocks and files to achieve the final shapes.
I trial assembled and match drilled the elevator ribs, spars and skins. I also fitted and match drilled the trim tab hinge to the rear spar.