Science and knife steel question about Patina and High Carbon steel blades.

[T. Erdelyi]

We all know how a Patina can protect a blade from rustin', my question is does a patina affect the edge of a blade, (hardness), does a full patina on a properly sharpened make the edge sharper or duller?

Or does it have no effect at all, is the layer of oxidation so thin that essentially it has no impact on the edge or it's sharpness?

 

[Planterz]

I'm no metallurgist, but I can't imagine that any sort of controlled corrosion or oxidation layer would be beneficial to the edge of a blade. No matter how hard it may (or may not) be, it would add either or both an amount of thickness and unevenness, and would thus be duller. And of course, any regular use and sharpening would remove the patina anyway.

 

[Joshua J.]

IMO. Yes, the patina will dull the edge (a little bit). However, the layer is thin enough that just a few strokes on a stone solves the problem.

When I soak my knives in Vinegar, they usually come out "feeling" just as sharp as before.

 

[carter13]

how do you get patina on an edge?

 

[J.Mattson]

how do you get patina on an edge?

There are a tone of ways to get a good patina on a high carbon blade and a tone of threads here talking about it.

Some of the favorites are soaking it in vinegar, mustard, sticking it in an apple, lemon or an onion. Basically anything acidic will have the effect your looking for.

I’ve forced a few patina’s but my favorite method is just to use it in food preparation. I personally like the look of the patina when it develops naturally.

 

[T. Erdelyi]

how do you get patina on an edge?

Actually it's on the bevel not the edge and ya can only only get a patina on a non stainless high carbon steel blade.

Any acidic medium, (oranges, ketchup, vinegar...) will accelerate the oxidation process and leave a patina on the blade.

 

[J_Curd]

We all know how a Patina can protect a blade from rustin', my question is does a patina affect the edge of a blade, (hardness), does a full patina on a properly sharpened make the edge sharper or duller?

Or does it have no effect at all, is the layer of oxidation so thin that essentially it has no impact on the edge or it's sharpness?

I know for a fact that the patina will need to be sharpened off the edge for the knife to be sharp again. I left a CB-JYD in vinegar over night accidentally, and it was mega dull until I knocked the patina from the edge.