Cleaning

Hand-wash in cold water, with or without soap, and dry straight away. Don't soak the blade or the handle, and never use a dishwasher.

Storage

Keep the edge from touching other objects: a drawer insert, a sheath, a cloth wrap or a towel. Magnetic strips are fine, but bare metal can scratch etched blades and damage an edge if the knife is pulled off carelessly.

Sharpening

Use Japanese whetstones. For a heavily used or damaged edge, start below 600 grit; for upkeep, 1000 grit and up. Finish on a leather strop. Stropping regularly keeps a fine edge for a long time. Protect the handle with plastic film and tape while sharpening. Avoid Tormek-style machines and other powered systems: they can easily ruin the finish and the carefully tuned profile of an HMK blade.

Patina (carbon steel)

Carbon steel reacts with food and moisture. Managed well, that reaction forms a patina that protects the blade from further rust. Keep the blade dry and rinse it in cold water to stop the reaction, and the colour will build evenly over the weeks. To speed it up, dry the knife only once, at the end of the job.

To remove patina or light rust, sharpen through it on a stone, or use a mild abrasive with a sponge, rubbing lengthwise with the other side of the blade resting flat. Note that abrasives also remove the satin finish underneath. Or bring it to HMK and Thomas will sort it out.

A Rönnberg Bowie in 115CrV3 (equivalent to Hitachi white steel) after months of daily use for cooking, hunting and fire-making.

Why carbon steel? It takes a much finer edge than stainless. The large chromium carbides in stainless steel limit how thin an edge can be; even M390, famous for edge retention, won't hold an edge much below 15°. That's why a true yanagiba is made from carbon steel.

Questions about looking after your knife? Email hotmetalknives@gmail.com.