# High Carbon Steel care tips?



## mangofreak (Apr 8, 2014)

I recently bought a yoshihiro knife for school and work and while I'm happy with my purchase I'm paranoid about maintaining it since I've only used stainless before this. So a few questions

1. Is a simple water/soap/dry after each use routine good enough to prevent rust? How much of a window do I have before I need to clean it(as I am not yet very quick with prep)
2. Is it true that touching the blade can cause rust? Will washing immediately after prevent that?
3. What problems should I watch out for? I've heard discoloration is normal an inevitable but I want to avoid anything that may destroy the blade

Any other tips are greatly appreciated.


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## denverveggienut (Mar 8, 2012)

1- Yes.

2- It depends on the knife. With some san mai knives, the outer layer can rust very quickly, in a very few minutes. Whereas, I've got a solid white #2 carbon-steel cleaver that i use a bunch. With it, I'm pretty much OK as long as I rinse and dry it before we sit down to eat. The knife will tell you what it needs. See #3.

3- Orange, red, or yellow rust is bad. If you want to go with a patina for easier care, the other colors are OK. It is very hard to destroy a blade through rust. If you get the bad kind of rust and//or want to clean off the patina, use Bar Keeper's Friend to get rid of it, then rinse thoroughly and dry as usual.


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## galley swiller (May 29, 2013)

With a carbon steel blade, it's not a bad idea to develop a gray "patina".  ALL steel knives have some sort of oxidation - it's just that with stainless steel, the desired oxidation is with the chromium - and appears silvery-shiny to our eyes.

The advantage to a good oxidation ("patina") is that the oxidation on the surface of the blade prevents the exposed surface iron atoms in the steel from reacting with your foods.  For that reason, it's often a custom to induce a patina.  Some like to have a go at a mass chopping of onions.  Others like to apply a mixture of mustard and vinegar to the blade.

If you don't allow at least a light patina (but insist on scrubbing the blade down to shiny each time), then you risk a chemical reaction between the newly exposed (and chemically active iron) on the blade and any acidic foods you might cut with the knife.

Also consider that each time you sharpen the knife (as opposed to honing), you are exposing freshly virgin steel to all and sundry.  That's one reason that sushi chefs in Japan will keep two sets of knives, sharpen the knives just after the end of work and let the knives "rest" for a day.  It allows the edges of the knives to naturally oxidize, and after that more-than-a-day of rest, the edges of the knives will not be as reactive.

DenverVeggieNut is spot-on about your need to look at the color and attack rust as soon as it appears.  Buy some of the green nylon scouring pads (avoid the metal scouring pads), some baking soda and some Bar Keeper's Friend.  Do keep in mind that BKF is slightly acidic, so it's not a bad idea after using BKF to use some baking soda to neutralize the residual BKF.

Galley Swiller


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## mangofreak (Apr 8, 2014)

So wait I'm confused now, is it a bad idea to wash it after every use then? I'd rather let a patina develop naturally. Will cleaning it all the time prevent that?


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## michaelga (Jan 30, 2012)

Some forced patina's can be amazing - there is a thread here [thread="31929"]What Kind Of Knife Do You Have [/thread] with contributions from a short timer that made some amazing designs.

Kristopher was his name... haven't heard from him in a while but his pics are still here.

He even explained how he did them - but you'd need a bit of artistry. Cool thing is if you don't like it - you can start over... just not too many times.





  








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## michaelga (Jan 30, 2012)

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Apr 9, 2014


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## kevpenbanc (Jan 18, 2014)

Mangofreak, no, you will not wash off the patina with soap and water. Wash the knife after each use. 
The patina will develop and change over time, depending on what you use the knife on.
Or you can force a patina as described by previous posters.
You will only remove the patina by scrubbing, not with soap and water.


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## galley swiller (May 29, 2013)

Properly done, the patina is an oxidation of the outer surface of the blade, and minimizes the ability of the surface iron from further reacting to any strong acidic or basic foods or food juices.  It builds up over time and is perfectly acceptable and to an extent, desirable.

No, it will not wash off.  It can be scrubbed off, and if you want to minimize it, then baking soda, green nylon scrubbing pads and elbow grease will do that job (I would suggest you only use BKF when you really need to bring a knife back to bare metal).

Yes, you need to wash off the knife after you use it, IMMEDIATERLY.  Not "tomorrow, some time", not "after the meal", not even "ASAP".  IMMEDIATELY means IMMEDIATELY, .And after washing, the knife needs to be wiped dry, then left where it can air dry further to allow the final moisture film to evaporate.  Only after that can you safely put the knife away.

Please note that I used the word "minimizes" above about the patina as a protective layer.  Nothing is an absolute protection (even to "stainless" steel).  Given time, a dirty knife can end up with the food residues breaking down into acids and eating through the patina to begin a rust spot on the blade.  That rust spot will invariably have the end result of pitting the surface of the blade - definitely a bad thing.

Which bring up several more basics

Good knives should never be put into a dishwasher - hand washing (preferably with hot, soapy water and moderate scrubbing to remove food residues, followed by running water rinsing) only, with immediate towel drying, followed by air drying.

Never, never, NEVER leave your knife in standing water.

Just simple procedures, repeated until they are reflexive.

Galley Swiller


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## robertoo (Mar 4, 2014)

look at th



is video


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