When it comes to marine metals, appearances can be deceiving. The shiny surface on that brand new stainless steel cleat could really be concealing cheap, highly ferrous metal, while that green crusty silicone bronze seacock could be as structurally sound as the day it was fabricated. As part of a series of articles focusing on problems that plague older boats (as well as poorly built new ones), Technical Editor Ralph Naranjo helps pinpoint potential trouble spots for metal parts and hardware.