I deburred the upper and lower cowling hinges and prepped the cowlings to receive the #426 rivets. Before riveting on the hinges, I sanded and painted the area where the hinges attach to get rid of the nasty pink color. The edges are painted Lycoming Gray. Next I squeezed the rivets to fasten the hinges and made the lower cowling guide pins out of stainless steel. The bottom cowling fit in easy. Tomorrow I will make the upper cowling guide pins and attach the upper cowling.