Thread: Forced patina on carbon steel

I have never done a razor, but carbon knife blades patina nicely with warm vinegar or most any fruit juice. The process mentioned above will give nice results

I've used the vinegar technique on a few knife blades and it doesn't seem to affect the sharpness, but I do a 12k hone and CrOx afterwards because I like a shiny bevel.

Back in the early 80's when I was young and dumb I used "Limeaway" cleaner on one of my straight razors. It was etched it black and the surface felt like it was galvanized. No longer smooth, it took a lot of buffing and cleaning to get it off. Be sure what ever pattern you want on your blade that it will be very hard to get off if you don't like it, like a tattoo.

Mustard is in the "etc" category!

How about downfalls of a forcing a patina? I see one user stated a brittle edge. Lets just not talk about the "Limeaway" cons! hahaha

Originally Posted by dghardyjr

How about downfalls of a forcing a patina? I see one user stated a brittle edge. Lets just not talk about the "Limeaway" cons! hahaha

Mike Blue put that one to bed. As there are very few people with his level of experience and knowledge of blades and metallurgy, I'm pretty happy to believe anything he says on the issue.

I used yellow mustard on my Gotta 120. The blade was all scratched up so I decided to polish it out and darken it. After a few tries on a test razor, I really like how it came out. I kept rubbing the mustard onto the blade with my fingers for about 5 min, rinsed in hot water then dried it off.

Originally Posted by RezDog

Mike Blue put that one to bed. As there are very few people with his level of experience and knowledge of blades and metallurgy, I'm pretty happy to believe anything he says on the issue.

All I know is that some people experience problems with different staining chemicals. But they all seem to disappear after the first sharpening.
My own theory is that the carbon steels actually rust at the very edge and the first use after the staining removes that rust and now its not that sharp anymore. I have also read reports of brittleness at the edge (can't remember forum (but it was a kitchen knife forum I think) or steel or chemical but the steel became chippy until a new 1k bevel was put on there, and then the regular progression iirc).

Sure some chemicals are more aggressive than others. What I've picked up from the kitchen forums is that mustard, blood, onions makes nice colors. nicest patina I've ever seen was made by splashing blood and then mustard on the blade iirc, turned out light brown and blue/purple (probably only visible in some specific angle and in some specific light situation, I'm guessning the colors are a result of destructive/constructive interference, like anodizing Ti), but it was cool looking.

Onions seems to be a favorite since after a few passes through an onion (and left soaking for 5 mins) the blade seems to "passivate" (but this is probably not completely true). It is what it is.