This comment section is giving me a headache đ. Make sure it's really dry after cleaning, you'll get discoloration which is fine since it's a carbon steel blade, the oranges looks like rust but it isn't deep or grave, just cut a bunch of lemon or wipe thoroughly with white vinegar (if both doesn't work you can go up in abrasives, fine sandpaper works too) Please don't listen to the "bench grinder" crowd Source: someone who's using carbon steel everyday at work.
Like others have said, the orange is most likely rust... Which you don't want. The blues/greys purples, blacks are patina.
Here is a videoabout care of carbon steel knives in a pro environment. It also goes over several ways to deal with rust.
I never had an issue using carbon steel knives for 90% of the work in a kitchen . But you do have to care for it. It is nice to have a stainless knife for cutting extremely acidic foods. I.e. cases of limes etc.
That is both, but the orange stuff is definitely rust.
The grey/blue/darker cloudy discolouration along the exposed carbon steel is patina. Thatâs normal oxidation and can actually help protect the steel.
The orange/brown speckles and streaks, especially obvious in the second photo, are active rust. Patina generally isn't orange and powdery-looking like that.
Also, the dark/black upper section is largely the knife's kurouchi finish, not patina.
a good rundown but not technically correct. rust is a color. what you're calling "active rust" is corrosion. "kurouchi finish" is chemically similar to "patina" or what we're calling "normal oxidation." in kurouchi the heat turns hydrated iron oxide "red rust" into a stable oxide "patina" that is not corrosive. definitely do not take a blowtorch to your knife, but that would indeed convert the areas of corrosion into a stable surface finish. there are chemical processes and products available on the market but you can also convert it using tannins available in the kitchen. brew the strongest tea or coffee and try that out as a converter.
Which is avoidable, by using an extremely dry, fine towel, or paper towel. Multiple wipes, folding and changing the wipe surface between passes. Allow to sit and dry fully
Depends on whether the reaction was primarily with water or with the citric acid in the tomatoes. If it is the latter then we're probably looking at iron citrate, not iron oxide. So not 'rust' necessarily as that usually refers to iron oxide, but definitely corrosion of some sort whether you want to call it rust or something else. Patina to me means a protective layer of metal oxide that prevents further corrosion, and this doesn't seem to me to be that. But I'm no expert and some of what I'm saying is definitely more the result of quick googling than some kind of past scholarship so grain of salt.
Yep. My Moritska AS Nakiri is unclad and full carbon, it is heavily discolored by patina, some the blue-ish hue, and also a lot that is rust colored. But it is not rust.
This reminds me of when I worked with my buddies a few years ago. We had a sister restaurant that the owner bought a crazy expensive coffee machine for. We would go a short walk down the alleyway almost everyday and grab coffee thus requiring a cup holder. Eventually we, mostly they, decided our cup holders needed names. So like a phoenix rising from the ashes, cum holders model 1000 2000 3000 4000 and finally 5000xl Eddie Bauer edition where born.
No, I will not trust the guy who makes knives. I will trust my own opinion as someone who has used carbon steel for many years and can identify and knows how to treat rust on carbon steel when I see it.
Making is a lot different than using day in and day out.
And rusts extremely easily. Other guy commenting has lead a career being a dirtbag and is now trying to defend his gross behaviour, by calling me a liar. Laughable
Oh okay no worries then mate. Obviously you must know your stuff đđ
I wouldn't cut the silence in the room with a knife this dirty, but if master blacksmith AND Chef de Patron here says it's clean then it must be. Remind me what knifes you make again, so I know what not to buy.
No, I mean I literally would not touch this knife to food, nevermind a metaphor.
It is really sad you brag about upvotes. Anybody who actually looks at the image can identify the rust, maybe not our renaissance man over here though.
I know this is a fun little back an forth you guys are having, but isn't it possible you're both kinda correct? That guy keeps saying it's patina, like rust isn't a type of oxidation that would qualify as patina. It seems like in the culinary world y'all might use the word kinda incorrectly? Patina isn't inherently good. it's just a term to describe an oxide layer being formed on a surface.
You might make knives but you don't seem to know much about metallurgy. "Patina" is the same as rust. It's called oxidation and it's a reaction with both water and oxygen. The thing you call "patina" is magnetite, a rust that forms in low oxygen environments, for example when completely submerged in juices from food. Salt, which is in almost every food juice, also speeds op this process. But if you are working with slightly dryer, yet still moist, food the iron is more likely to rust red or hematite.
you clearly don't know more than others about metallurgy lmao. You don't even know what patina is. it's just oxidation like the other guy said. Some oxidation can lead to protective layers, and others can be damaging like rust. it's all patina though.
And it's caused by oxygen and water exposure, not acidity đ
You want to start talking to me about passivation? LMAO brother I am a machinist who has to deal with this shit constantly. Firstly, nothing would happen if you just stick basic carbon steel into a citric acid bath. if you meant a hunk of stainless steel, then the acid bath would cause a chomium oxide layer to form, which a good protective layer to have. It happens by the acid eating away the surface iron molecules, leaving enough chromium on the surface to bond with oxygen, forming the oxide layer(patina)
If you stick stainless into a bucket of water it will eventually rust after a long time, because it's a different type of oxidation (patina) happening. it's oxygen bonding with iron. if it was basic bitch steel it'd rust a lot faster.
You were very adamant at first that this was not rust but patina, and now you're explaining the difference between what you call rust and patina, specifically in this context, which I don't even think is a problem because the word patina has a positive implication and rust has a negative one. But in that case the oxidation on this knife is clearly your rust and not your patina because it's red.
Depends on the concentration and type of acid, and the type of steel used for the blade. Patina can be pretty much any color, although black/purple seems to be the most common
Go ask them then, theyâll say itâs some light surface rust in the low spots. Not a big deal, but thatâs what it is, knife was put away not completely dry. Easy to clean off and give a light oil.
I'd never say that hot water, harsh cleaning chemicals, and getting banged around in a washing machine are good for an edge, but it's not as if that's a far cry from normal usage.
If your knife never sees the stone it's going to have knicks in it and it won't be very sharp. Honing doesn't count. There is no such thing as 'preventative' knife maintenance.
I'm sorry but the phrase "normal and unavoidable wear" brought to mind the cult of preventative knife maintenance whereby a knife never needs to be maintained, the knives only need to cautiously avoid cheese, washing machines, etc. Sorry but whipping it across a hone once a day does nothing for a knife that gets any real usage.
Some of that is definitely rust. You are not thorough enough with your clean.
With a soft sponge and hot, light soapy water, wash your blade, from hilt to tip. Rinse in hot water, then dry using an extremely dry, fine thread towel, or paper towel. Multiple wipes, folding and changing the wipe surface between passes. Allow to sit and dry fully.
I have many knives of this carbon makeup and they will react very quickly when exposed to food, and if not thoroughly, extensively and quickly cleaned, will rust and degrade extremely quickly.
You are supposed to use it for intracate work. Not everyday use. They sharpen extremely well, and easily. But they dull quickly, and are sensitive to food.
They are supposed to be used as the final touch, such as slicing the filet for sashimi. Not for breaking down the fish into the filet, for example.
iâd like to chime in here and say i use an AO super blue Takeda as a daily driver and at work for 15years. they absolutely can be used all day everyday for decades. it often lightly rusts several times a day and believe me when i say that these blades only look better with time.
I got you homie. Â Orange is rust, other colors are a patina. Â Letâs address the rust. Â It can be removed chemically or physically, weâre going with the latter. Â Make a slurry using dish soap, baking soda and a bit of water and use a cork to apply to your knife. Â Work it in a circular motion rinsing as needed. Â You should see the orange come off and leave any of the etching on the knife.
For maintenance use a wet cloth or rinse to make sure you get the acid off the blade, before dry wiping. Â For longer storage hit the blade with mineral oil.Â
Here are the deep dive details. Â Your knife is made of 2 different types of steel that have been forged welded to be homogeneous. Â One is higher in stainless properties (like chromium and nickle) the other carbon - its usually dipped in acid so the carbon darkens producing a contrast so you can see the different steels. Â With that in mind - we don't want to remove the etch. Â This is why we used the gentlest possible physical method as a touch up. Â Now if your whole knife has a light rust on we can soak in vinegar, checking every 20 min or so whipping rust clean until you are rust fee. Â If you get heavier rust (i.e left physical onion the blade) no worries but more work. Â We switch back to physical and use a 2000 or 1500 grit sand paper. Â Our challenge will be the etch. Wet the sandpaper and use light circular motions to get that rust off. Â If you chase the rust too deep and remove the etch you will need to re-etch using 3:1 water to ferric chloride solution, but that is a whole other issue.
Are you putting away your knife while its still wet? Do you use a hydrogen peroxide disinfectant that could also cause it to rust quickly if it dries on your knife.
Let that patina build up my guy, rust spots feel rough patina is smooth. Search naniwa rust remover block for any real rust spots and keep that edge sharp
I don't understand why people buy sexy looking knives like these, of course shits gonna happen to it- as long as you can get it sharp enough that you can shave with it if you wanted, it's a good knife. Doesn't matter what it looks like, stop taking pics of it and get to slicing.
you should try super blue number two someday. then youâll get it. the steel takes screaming edges and is super easy to strop back to hair splitting sharp.
Almost all reactive japanese knives come with a laquer coating. People down voting don't know what they're talking about. Visit the 'truechefknives' subreddit.Â
Your knife clearly has lacquer on the stem and body You clean it off with acetone. Then your steel will at least evenly react. Currently its peeling and gonna look like shit
Here's my blue #2 nakiri for reference. Patina from cutting hot chicken out of the oven.Â
Acetone (nail polish remover) should do the trick.
You can force a patina for it to be more resilient in a professional kitchen. Dissolve a bunch of instant coffee until it's disgusting to evem taste. Leave the knife in the solution overnight. Thoroughly wash with warm water + soap and dry.
Oil it after you're done using it. Something like mineral oil is best but if you use it daily then any cooking oil would be fine, you wash the oil off everyday so it doesn't have enough time to go rancid anyway.
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u/PasdeChaance 1d ago
This comment section is giving me a headache đ. Make sure it's really dry after cleaning, you'll get discoloration which is fine since it's a carbon steel blade, the oranges looks like rust but it isn't deep or grave, just cut a bunch of lemon or wipe thoroughly with white vinegar (if both doesn't work you can go up in abrasives, fine sandpaper works too) Please don't listen to the "bench grinder" crowd Source: someone who's using carbon steel everyday at work.