I have a few steel parts for my plane (hinges, eyebolts, controls, etc...), how do you recommend preparing them before install? Should the aircraft spruce eyebolts with cadmium coating be cleaned, primed, and painted? Or just the sheet metal that I create parts out of? What specific chemicals and where can I find them (including type of paint that is appropriate). What about my aluminum gas tank? Does it need to be treated in anyway? The aluminum cowling?