I fastened the lower engine cowling attach hinges to the firewall this morning. The hinges were alumipreped, alodined and the primed before being riveted in place. I will attach the upper hinge with the installation of my avionics. I made a few tools to help me when I build the doors. Two of the tools are hole locaters... One #20 and one #30. Also made a hidden edge locator which will be needed to find the edge of the door. All three tools were made out of the steel bands that came from Vans.