I found out the hard way on the weekend how quickly mirror polished carbon steel patinas when using them. After a good day of speckle fishing, Dad and I came home to clean our specks, and I decided to use my recently finished knife. I brought the knife inside right after cleaning up our catch, and noticed it had very ugly brown spots. Of course it wouldn't clean up, so I decided to try forcing patina into mine and a little skinning knife I made for a buddy of mine made from same steel. The first pic is the skinning knife. I gave it another good polish and cleaned the blade with rubbing alcohol. I boiled 3 cups of water and mixed in 4 big tablespoons of instant coffee. I soaked it for about an hour and ended up with this. For mine I polished and cleaned the same and used a rubber bristled basting brush, and brushed on some yellow mustard. Let that sit for 45 minutes or so and cleaned off. I mixed up the coffee again but used 3 tablespoons of coffee. Bit of a glare in pics and made around bottom of blade look blotchy, but it's very even
if you want a patina quickly get a small container of Muriatic acid. Sold at hardware stores for cleaning concrete
