Living with carbon steel

Carbon steel is not high-maintenance. It is low-maintenance with one rule: do not leave it wet.

After use, wipe the blade dry. That is the entire daily practice. If it has been in something acidic — citrus, tomato, onion, blood — wipe it sooner rather than later, because acid accelerates everything.

Before it goes away for a while, put a thin film of oil on it. Mineral oil is food-safe and cheap. Camellia oil if you want to be traditional about it. Motor oil if you are out in the field and that is what you have; it will not hurt the steel.

Let the patina come. Within a few weeks of use the blade will go from bright to grey-blue, and that layer is a stable oxide that physically occupies the ground red rust would otherwise take. People who scrub their patina off every week are working harder and getting a knife that rusts more.

What actually causes damage: sitting wet in a sheath, going through a dishwasher, being left in a sink, and being put away damp. Kydex holds no moisture the way leather does, so the knife can live in its sheath — as long as it goes in dry.