How to care for carbon steel knives?

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How to care for carbon steel knives?

Post by ChefKnivesToGo »

Hi


I am a newbie to high-end Japanese knives and currently use a vg10 yoshihiro gyuto and kramer sg2 Damascus chef's knife. I would like to venture into Japanese knives made with AS with a Kurouchi finish to diversify my budding collection. I was thinking about a Moritaka AS knife but I am very concerned about oxidation/ease of care. I never owned a carbon knife before but love the look of the Kurouchi finish. I don't mind wiping dry the carbon knives but applying oil to it each time after use is not ideal for my personal use.

I just ordered a Masakage Koichi 210mm from your website because it seems like the stainless steel clad will help with ease of maintenance yet it has a Korouchi finish. I am also looking for a sujihiki and petty etc but everything in the Masakage Koichi line is sold out. I plan to use the gyuto a majority of the time so will be cutting tons of acidic items. I also like the fact that the video review said the M. Koichi is a little more stout since I will be using it as an all-purpose knife (except boning etc).

My questions are -

1. Is there a significant difference in the ease of maintenance between something like the Moritaka AS and the M. Koichi lines due to the difference in cladding? Again, assuming the stainless is "better" for ease of maintenance than the iron cladding?

2. If the answer to question 1 is yes - are there other lines of knives you'd recommend with an AS core and a Kurouchi finish but with stainless clad?

Would love to hear your insight into my questions and pls list any recommendations if possible.

Thank you so much for your time!
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Re: How to care for carbon steel knives?

Post by taz575 »

I have several all carbon blades; some are mono carbon and others are carbon clad in mild steel/iron. I just wash them with hot soapy water and dry fully with a paper towel after they are washed. No rusting.

What I have found helps with the reactivity/ease of maintenance is acid etching the blades in a dilute solution of ferric chloride (1 part acid added to 4 or 5 parts water). This darkens the blade (hard carbon turns very dark, lower carbon is more of a greyish color) and the steel on the outer surface etches and seems to be less reactive going forward. After etching the blade, I thoroughly wash it off with hot soapy water, dry with paper towel (regular towels often leave water droplets), and then wipe the blade with a paper towel with some mineral oil on it and let it sit for a while, then wipe the excess oil off. Thats the only oiling I do on my carbon blades. Even ones that haven't gotten used for 5+ years have been fine w/o rust stored away.

If you don't want to use the ferric chloride, you can force a patina with mustard or other ingredients to make the steel react quickly, which will help keep it from reacting a lot. I found cutting onions gives the blade a more brownish/rust color patina, but proteins gives it a more blue/purple patina. I would often use a new carbon knife to slice down a roast and then leave the blade between slices for a while to get the blue/purple patina.

Carbon blade with patina with the blue handle on top:
155804180_151081446842106_4854290092817795077_n.jpg
Freshly etched blade, no patina:
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Re: How to care for carbon steel knives?

Post by Miles »

1. Great question and made me think- That Koichi is sweet and what's interesting about it is the finish is that it's KU over stainless clad. Typically kurouchi finishes are with iron clad. I believe the Moritaka is iron clad KU (with a stainless tang). As taz575 mentioned a patina will help so it's basically the cutting edge and the blade road. Still gotta wipe, whether dry or damp towel while using...

2. for your sujihiki- if you're doing proteins, not as much concern about acidic foods. Might consider more steel options than AS- W1,2,B1,2
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Re: How to care for carbon steel knives?

Post by jknife »

It seems more and more makers a cladding with stainless these days.For example Kohetsu blue #2, Takeda NAS, Kurosaki AS, and my favourite Anryu AS. These are all kurouchi finish and this list is just off the top of my head and is by no means exhaustive. I own a few of these knives and maintenance is really not a problem. Just don't leave them wet. I have never used oil but then again I don't live in a rainforest or on an ocean, unfortunately. I agree with Miles that AS is the best for acidic foods.
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Re: How to care for carbon steel knives?

Post by Jason183 »

ChefKnivesToGo wrote: Sat May 08, 2021 9:33 am
My questions are -

1. Is there a significant difference in the ease of maintenance between something like the Moritaka AS and the M. Koichi lines due to the difference in cladding? Again, assuming the stainless is "better" for ease of maintenance than the iron cladding?

2. If the answer to question 1 is yes - are there other lines of knives you'd recommend with an AS core and a Kurouchi finish but with stainless clad?

Would love to hear your insight into my questions and pls list any recommendations if possible.

Thank you so much for your time!
The Iron clad KU(true KU) can still form rust if the KU wear off and leave it unwiped.
The stainless clad KU( Fake KU) doesn’t form rust, and doesn’t wear off easily overtime, but the cutting edge will still form rust if leave it unwiped.

I think Yoshimi Kato also does AS in stainless clad KU, I have tried one of his Kanehiro AS in Nashiji finish before, very high performance blade, but don’t know if it suits you or not because it’s laser thin behind the edge.
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Re: How to care for carbon steel knives?

Post by gladius »

My Moritakas are not too reactive. They build a patina quickly and are stable. Use and wipe - fantastic performers!
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Re: How to care for carbon steel knives?

Post by nyudoc04 »

Hi all -

Thank you SO much for the detailed info, suggestions, and insights. I am very grateful to have found such a welcoming forum/members!

This is my first foray into carbon knives so I hope things go well with the Masakage Koichi gyuto :) I will do some more research and grab a petty from CKTG very shortly. Deciding between the 150mm Kanehiro AS or Gihei HAP40 currently. My wife is not very careful with her knives so need to keep the carbon ones out of her hands. :lol:
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Re: How to care for carbon steel knives?

Post by ChefKnivesToGo »

Sure thing and welcome!
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Re: How to care for carbon steel knives?

Post by Radar53 »

In terms of drying my carbon blades, the last medium I use is a micro-cloth to get rid of the last vestiges of moisture. So I'll use a dry tea towel, sometimes a paper towel and finally the micro-cloth.
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Re: How to care for carbon steel knives?

Post by nyudoc04 »

Changing subjects slightly.

What is the difference between AS/Blue 1/2, Hap40, and Konosuke GS+/HD2 in terms of difficulty to sharpen? I have only semi successfully maintained my SG2 and vg10 knives as I'm a newbie sharpener. I'm guessing I should stay away from hap40 for difficulty of sharpening?

As stated above, I bought a masakage koichi AS from CKTG (arriving next week!) and I would like to get a 240mm gyuto as well. Thinking of a Togatta (either Kohetsu Hap40 or Konosuke GS+ or can wait for an AS with stainless steel clad) - will the shape be okay for a primarily push cutter like myself?

Thanks all for your advice!
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Re: How to care for carbon steel knives?

Post by Altadan »

nyudoc04 wrote: Sun May 09, 2021 9:35 pm Changing subjects slightly.

What is the difference between AS/Blue 1/2, Hap40, and Konosuke GS+/HD2 in terms of difficulty to sharpen? I have only semi successfully maintained my SG2 and vg10 knives as I'm a newbie sharpener. I'm guessing I should stay away from hap40 for difficulty of sharpening?

As stated above, I bought a masakage koichi AS from CKTG (arriving next week!) and I would like to get a 240mm gyuto as well. Thinking of a Togatta (either Kohetsu Hap40 or Konosuke GS+ or can wait for an AS with stainless steel clad) - will the shape be okay for a primarily push cutter like myself?

Thanks all for your advice!
Without answering your question in full, I can chime in and encourage you with the fact that carbon steels (i.e., the non-stainless ones) such as AS, Blue #1, #1, White, etc. etc... will respond much more readily to the stones, and so will sharpen more easily/quickly.

VG10, it seems, varies depending on the maker and the heat-treat (this is very true for all steels, actually. VG10 is just so ubiquitous).
HAP40 has indeed given quite a few sharpeners a hard time, though I believe it often comes down to the specific stones they have on hand (those are not all made equal either).

I've never handled the HD2 or the GS+, but I expect the latter is closer to Ginsan (G - S?) and hence, should be rather easily sharpened, despite having plenty of chromium (=stainless)

Hope this helps. There's plenty more to say on all of this
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Re: How to care for carbon steel knives?

Post by Jason183 »

Ease of sharpening from easiest to most difficult IME
White 2, HD2, white 1, blue 2, GS+, AS, R2, vg10
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Re: How to care for carbon steel knives?

Post by stewssy »

For me, wipe after each use, if it’s patina I use a rust eraser, and then dry. I rarely use camelian oil. I’m a line cook, and even though it’s a neutral oil, I prefer not to have it on my knife
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Re: How to care for carbon steel knives?

Post by jacko9 »

This is the opinion of a home cook that only prepares meals for my wife and I. I have Semi-Stainless, Soft Iron Clad Carbon Steel, Stainless clad Carbon Steel and none of it is a problem, I just rinse or wipe with hot water and dry. If the soft steel develops a patina I love it, if I don't want the soft steel to keep developing a deeper patina I use Renaissance Wax to stabilize the soft steel cladding. I know that I read a lot about maintenance issues but really unless you do something like use a dishwasher or let it sit in a sink wet, there is no problem.
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Re: How to care for carbon steel knives?

Post by d_rap »

Certainly my experience as well. With just a bit of care any of these knives are plenty easy to maintain, at least for a home cook. I rinse and dry as I work, but frankly I do that with all stainless as well. So yeah, reactive, you don't leave that last bit of tomato or onion on the blade as you dig into the meal, but that's just one last rinse and wipe.
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Re: How to care for carbon steel knives?

Post by nyudoc04 »

Really appreciate everyone's insights and taking the time to respond. I look forward to using my first carbon steel knife!
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Re: How to care for carbon steel knives?

Post by nyudoc04 »

Got my Masakage Koichi!

Question - Is the finish between the tang and handle normal for a higher end knife? pls see pic! Looks a little patchy with some type of white rubber/glue around the tang. Should I be concerned about water/seal issues in the long run? Thanks all!
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Re: How to care for carbon steel knives?

Post by d_rap »

Congrats!

Fit and finish varies on the seal-up, and while that's admittedly not great it's certainly within the realm of "normal." If any of the unevenness or excess really bothers you you could take it down a bit more flush carefully with some fine sandpaper (possibly wrapped around a screwdriver or a triangular or flat file, just be careful, accurate, mask the ferrule...), but the aesthetic is that these are working tools, and handles are replaceable and swappable down the line and all that. Personally I wouldn't bat an eye if that was my knife.

I'm only a couple years in here but on a few of my heavily used knives I'm seeing some areas of imperfection develop where water could get in. But the fixes are so easy--beeswax, epoxy, etc.--that it's nothing to worry about. If you do see any possible points of ingress for water, address them. This forum, the website and the internet are filled with ideas about how to secure the seal between tang and handle.
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Re: How to care for carbon steel knives?

Post by taz575 »

You can take a single edge razor blade and clean up the excess putty/sealant if you want. Basically press the blade down into the stuff to level it off with the handle.
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Re: How to care for carbon steel knives?

Post by d_rap »

taz575 wrote: Sat May 15, 2021 2:57 pm You can take a single edge razor blade and clean up the excess putty/sealant if you want. Basically press the blade down into the stuff to level it off with the handle.
Yes, better suggestion than mine, assuming the sealant is soft enough to cut and it looks like it is, and that's probably typical.

Thanks taz.
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