I confess that initially I was stuck for something to write on a nautical theme that started with ‘I’. ‘Island’ was just too easy and not necessarily nautical, so I settled on Inox. Inox, from the French acier inoxydable, is the term used in Europe for stainless steel. ‘Stainless steel’, by the way, is bit of a misnomer. Steel is purified and heat treated iron with a bit of carbon added to it to harden it. Inox, or stainless, is a true alloy with up to 20% chrome and 37% nickel. Like Bronze is a combination of copper and tin or brass is a combination of copper and zinc, stainless steels are a true amalgam, not simply a treated form of iron. Most Inox alloys are not even magnetic. Inox is of course, widely used in the marine industry because of its resistance to rusting and corrosion. But this is not a perfect world, and neither is Inox. Pardon my delving into engineering here, but Inox, paradoxically, depends upon oxygen to maintain its stainless quality. It’s the chromium that does it, because when the chromium in Inox is exposed to oxygen it forms an inert layer of oxidation that protects the underlying metal. So on deck or underwater where there is a good supply of oxygen, there is no problem. However, if it’s a propeller shaft enclosed in a stern tube, a keel bolt surrounded by wood or other part simply covered with marine growth, thus deprived of oxygen and in sea water, the oxidized layer of chromium breaks down, leaving it to rust and corrode like ordinary steel. That’s one reason your propeller shaft gland (on inboard engines) should drip a bit, to feed oxygen to the propeller shaft.
One little tidbit that’s’ not really really nautical, but the name Victorinox, the company that makes Swiss Army Knives, comes from the two words Victoria and Inox shoved together. The founder of the company Karl Elsener was supported greatly by his mother Victoria in his business endeavours, so when she passed away he named the company after her and the name of the material he used for his famous knives. This was in 1891 that he first started supplying knives to the Swiss army, that’s the one on the left above. Thanks, Mom.
All right, enough engineering. Tomorrow will be simpler, I swear.