In this series of pictures I got some advice from my EAA Tech Rep to place some aluminum foil in between the belly skin and the reinforcement plates AND between the reinforcement plates and the backer plates; then rivet the reinforcement plates to the belly. Apparently, the reinforcement plate won't provide adequate reinforcement if it's not riveted. Then I dimpled the belly and riveted using flush pop-rivets. The first picture is comm 2 antenna reinforcement and backer plates. Picture #2 shows the riveted renforcement plate completed. The last picture shows comm 1 & 2 antenna's mounted.