John Harries and Phyllis Nickel's excellent website, Attainable Adventure Cruising, has a series of posts discussing the design for the "perfect" voyaging boat. John and Phyllis call the design the Adventure 40 and through the design process, John examines various elements of a voyaging boat and how they could be improved. In his latest post, John considers stainless steel and why it might not be the best material for building chain plates.
"Stainless steel chain plates, particularly if they are set inboard and poke up through a slot cut in the deck, will, if the boat is sailed hard offshore, eventually leak, usually within a few years of launching, sometimes much sooner.
"And once water gets in, the chain plate itself starts to corrode—a problem that is serious enough that any boat so built that is more than ten years old should have its chain plates carefully checked, and after 20 years replacement is often the only safe alternative."
