What does a Patina do on a carbon steel blade? I

[simko]

Whats the benefites/down points of having a patina on a carbnon steel blade?

and....

if theress a patina on my knife, can i still cut and eat my food with it?

 

[Don Luis]

Like blueing does to a gun (blueing is a patina), it forms a coating that gives some protection, preventing rust.

Yes, it can be used for food, as it was with all knives before there were stainless steels, just make sure you clean and dry the knife after use.

 

[El Lobo]

Various foods,(eg potatoes, lemons, limes, tomatoes), which are acidic are actually used to put a patina on a high carbon content blade. Vinegars are another way to put a protective patina on a blade.It is really a form of oxidation, but it helps retard rust, except for right on the cutting edge, where you would steel or sharpen. So as Don Luis said, just wash and wipe them off so they are sanitary, and cut away!


Bill

 

[Eager]

What it does is called "passivation". The patina is an iron oxide layer that has formed on the surface. Once this patina layer has formed it "uses up" the iron atoms on the surface and doesn't let them easily form the bad kind of rust, which is also another form of iron oxide. The patina is a "pasive" layer of iron oxide, meaning that it doesn't keep eating into the steel and slows down the formation of the steel eating reactions. Source: I'm a chemical engineer and had a course in corrosion in college, but I'm far from being an expert on this, and hereby disclaim all that I've said. Any part of this that's actually right would be pure coincedense.

 

[berettaman12000]

I love patina's on carbon steel blades as they make it much more difficult to rust/corrode. Yes, you can cut food with them. I think they look cool and does away with the "shine" of a blade while hunting.

 

[rev_jch]

It creates a thin coating of corrosion that acts as a protective coating (such as blueing, plating, etc.).