Care for Japanese chef's knife - chips, rust, etc

sygyzy

sygyzy

Joined
Apr 29, 2003
Messages
339
Hi,

I have a Watanabe blade that I use daily for cooking. It's my primary knife. However, I have noticed some problems with it, due to my neglect. I would appreciate any assitance I can get in this matter.

1. The blade is not stainless which is traditional to Japanese knives. I wash and wipe down the blade after each use but there is still oxidation. I get rid of it by using fine grit sandpaper and wet sanding it under running water. I try to avoid the edge as much as possible, to prevent from accidentally sharpening (or dulling) it. Is there anything else I can do? Is there any sort of oil or film I can put on it to lessen rust? Maybe mineral oil or that stuff from Sentry?

2. I noticed little chips in my edge. Is there anyway I can do something about this? I bought a Norton whetstone. Will I be able to grind this out?


watanabe1.jpg


watanabe2.jpg


watanabe3.jpg


watanabe4.jpg


watanabe5.jpg
 
Yes, but you might have to start at 220 and work your way back up through the polish stones (or just ignore it and let it slowly wear out with repeated sharpenings). If you chip it like that the edge might be a little thin for your style and you may want to increase the bevel angle a few degrees.

Most people don't try to polish the blade all the time and instead intentionally form a protective coating of gray oxide on the blade by dipping in vinegar or sticking them in potatos etc. You can coat the blade with oil to prevent rust... camillia oil are non-toxic and will not go rancid. http://www.epicureanedge.com/shopexd.asp?id=13&websess=63222419735988 Drug-store mineral oil will work too (vegetable oils etc. tend to go rancid)
 
A scotch-brite pad will clean that knife right up.

What caused the chips? Do you use it on bone?
Some time with a stone will get those out. Take your time and don't rush it.
 
It is very difficult if not impossible to keep those blades free of rust depending on which foods you cut. Some acidic foods can be so corrosive to those steels that the oxidization can form while you are cutting. Generally you just live with it unless you want to polish the blade after each use. In time the oxidization will stabilize to a uniform coating.

-Cliff
 
If this is anything like Murray Carter's knives, and it appears to be, those chips will occur if you cut anything harder than meat, fruits, and vegetables. This is not necessarily a "bad" thing as it shows the knives are ground very thin and left at a high hardness, both of which makes them great for their intended tasks. The thin blade also means the chips will sharpen right out.

John
 
Hi everyone, thank you for your responses.

Some followup questions.

Is it dangerous to use the knife with the oxidation on it? I cannot polish it everyday so we (my roommate and I) just use it as is. So far, we haven't gotten sick.

How would oiling the knives work? Would I cook, then wipe down with oil, then store? The knife gets used so often, I can imagine a scenario where I am done with my meal, wash and oil the knife, and put it away, then my roommate starts cooking and gets oil on his food. I know it's non-toxic but that sounds sort of weird. Do most people oil their blades?

How do I get the good (gray) coating rather than the ugly rust coating?

We are not cutting bone with this. I think it might be our cutting board, though I do consider it a "soft" plastic. We cut veggies (onions, mushrooms), meat (beef, chicken breast, fish filets), and occasionally fruit. We do not debone anything whatsoever. I am not sure where the chips came from :(

I will work on the Norton stone I have coming in, to see what I can do. I don't think I will change the angle (10-15 degres) because that will take away the point of having a Japanese blade in the first place.

Speaking of, does anyone have any sharpening advice? I have seen a few differnet webpages but they don't all agree.
 
Gotta love the AMAZING cutting you get from those skinny-stock, very hard-edged Japanese kitchen knives. But those edges can be a little fragile.

sygyzy said:
How would oiling the knives work? Would I cook, then wipe down with oil, then store?
Click to expand...
You got it.... cook, wash with soap, rinse, oil, store.... that's how it works.

If you use camellia oil you need not worry about getting it on food. It is non-toxic. You can get it at woodworking tool stores or iaido (Japanese swordmanship) vendors. Also, it only takes a few drops of camellia oil on a paper towel or cotton rag to do a Japanese santuko size blade. If you use a rag, it eventually has enough residual oil in it that you don't necessarily need to add oil to the rag each time you use it.

How do I get the good (gray) coating rather than the ugly rust coating?
Click to expand...
The best patina I got was using boiled vinegar. Heat it up in a pan on the stove or in a microwave until it boils. Take it off the heat, then set the carbon steel blade to soak in the hot vinegar for about ten minutes. At that time the steel should be a darkish grey patina. Rinse with water to dilute/eliminate residual vinegar from the surface of the steel.

If you want a splotchy "camo" kind of patina, you can daub a vinegary substance like mustard or Miracle Whip on the blade and let it dry out on the steel. There are pics of such a patina near the end of this thread here.
 
If you have a pebble surface on that cutting board, then that is probably what is doing it... sliding it sideways can do it, but probably you are twisting or slanting it a bit as it chops through something into the board so the sideways pressure on those little pebbles makes for tiny chips, though that big one may have had some other cause.
 
2nd Camelia Oil, works great. That's a pretty big chip, get a 220 grit waterstone, should come out pretty quickly.
 
I used carbon steel knives at catering college and still have them. I also have a number of Japanese knives, but they are all VG-10.

There are two ways you can keep your knife, shiny and clean, or dull and clean.

to keep it shiny and clean, put it flat on a cutting board and scrub it with a Scotchbrite pad (as mentioned) with a little washing up liquid. This will make it shine. Then rub it with vegetable oil. It won't go rancid as you use the knife too often. Each time you finish using the knife, wash and dry it and just put a couple of drops of oil on both side and rub it in carefully with your fingers. Alternatively, you can use a liquid butter spray like Pam and rub it in.

The alternative is to let it oxidise and go dull and grey, but either keep it dry so as not to rust, or oil it if it is in a mosture laden atmosphere.

Use an oil or water stone to remove the chips. The angle can be steep leaving a fine edge on a knife like that. If you chipped the blade, then you mis-treated it. That knife is a cutting knife, not a chopper or cleaver. I took a great chunk out of a Chinese Santoku type knife cutting a frozen piece of meat and twisting the blade. I sat down one Sunday afternoon whilst watching television and ground it out on an oilstone. It was fine afterwards and as sharp as hell!

Great book BTW, Anthony Bourdain is a great chef.
 
No the "patina" of the knife is in no way a health hazzard. However, the oxidation might change the taste of very delicate foods, if you haven't notices it yet, then don't worry about.

Sharpening: I would agree with the advice of increasing the edge angle a bit. You have just proven to yourself that the edge is too fragile for your purposes. Don't worry, even if you apply a much larger edge angle, it will still cut very well because of the blade geometry which is pretty thin. It will also speed up the removal of the chips. If you want to maintain the edge bevel, you have to lay the knife flat onto the bevel and sharpen away. If the blade is laminated, you have to take great care that you don't fall into the soft Jigane (surrondlng layers) and thereby decreasing the angle. Maintain pressure right at the edge. I won't lie to you, it takes some practice. Much easier if you increase the angle a little bit. This way you make sure that you are working right at the edge. As far as I can tell it is single bevel and concave on the other side. You can hone the blade flat on the stone on the concave side, again maintaining pressure at the edge, even there I would suggest to lift the spine a bit of the stone and increase the angle. However, you should be fixing the flaws from the bevel side. The other side (after you have trued it....assuming you have long done that), you polish up a little bit, which is really quick since the contact area is so small, but mostly pull off the burr.
 
If your knife is like mine, made of forged hitachi blue steel with a convex edge, I have a leather belt I taped onto a piece of wood, then I place various grits of wet and dry paper on top of the belt and strop it with water until the edge is cleaned up.

If the edge is chipped, I start at 220, then 400, then 600, then 800, then 1000, then 1200, then 1500 and finally 2000 grit. I finish up on the leather belt loaded with chromium oxide.

Hope this helps.
 
Thanks again for all your help guys. I honestly don't know how I got that chip but that suggestion that sideways force on the board or a twist may have caused it seems the most logical. Is there anywhere I can pick up Camellia oil locally? I saw the links you guys posted but I hate ordering cheap items and paying another 50% for shipping. It'll be impossible to convince my roommate to oil it too. On second thought - I'll probably skip this step for now.

I might try your technique flatgrinder but since I don't have a spare belt lying around nor that many grits of sandpaper, I am not sure when this will happen. I hope my Norton combination stone can work for now.

I will try to increase the angle a bit. How do you guys assure the angle you are after as well as guarantee it? That is, I think most Japanese knives are about 10-12 degrees. What if I wanted 18 degrees? I could just eye ball it but each time I went back and forth on the stone I might be doing 13, 15, 17, 19, 18 degrees.

HoB - I am still learning terminology but yes, this seems to be beveled on just one side (single edge), the right side. And it is flat on the other side. It does not seem concave on the other side. It might be?

Thanks again everyone!
 
Instead of busting a gut trying to find camelia oil, just use regular mineral oil, works great.
 
HoB said:
No the "patina" of the knife is in no way a health hazzard. However, the oxidation might change the taste of very delicate foods, if you haven't notices it yet, then don't worry about.
Click to expand...

I have noticed when cutting apples, a grey film deposited on the apple.

1. Anyone else notice this?
2. Should I be worried?
 
sodak said:
I have noticed when cutting apples, a grey film deposited on the apple.

1. Anyone else notice this?
2. Should I be worried?
Click to expand...

Yep. Nope. Smush up some iron enriched breakfast cereal and stick a NdFeB super magnet in there and you'd be amazed at the glob of iron filings that collect on the magnet.
 
sygyzy said:
Thanks again for all your help guys. I honestly don't know how I got that chip but that suggestion that sideways force on the board or a twist may have caused it seems the most logical. Is there anywhere I can pick up Camellia oil locally? I saw the links you guys posted but I hate ordering cheap items and paying another 50% for shipping. It'll be impossible to convince my roommate to oil it too. On second thought - I'll probably skip this step for now.

I might try your technique flatgrinder but since I don't have a spare belt lying around nor that many grits of sandpaper, I am not sure when this will happen. I hope my Norton combination stone can work for now.

I will try to increase the angle a bit. How do you guys assure the angle you are after as well as guarantee it? That is, I think most Japanese knives are about 10-12 degrees. What if I wanted 18 degrees? I could just eye ball it but each time I went back and forth on the stone I might be doing 13, 15, 17, 19, 18 degrees.

HoB - I am still learning terminology but yes, this seems to be beveled on just one side (single edge), the right side. And it is flat on the other side. It does not seem concave on the other side. It might be?

Thanks again everyone!
Click to expand...

The back of the knife should be slightly concave. You lay that side flat on a finer stone (don't lift the spine off the stone, but put your fingers near the cutting edge) and sharpen a few strokes to get the burr off (you actually sharpen on the front beveled side), you should notice a tiny polished ring around the edge of the knife as in this photo http://watanabeblade.com/english/pro/deba1802.jpg just a little bit of the steel along the spine and along the back of the cutting edge actually touch the stone (Japanese plane blades are slightly hollow on the back like that too, specifically to make sharpening the flat side easier) . Example with a rather thick deba: http://www.japanesechefsknife.com/HowToSharpen2.html

You can try taking care how you contact your cutting board before you reprofile your edge. Since your angle is all on one side, you can lay your bevel flat on the stone and see how many coins will fit between the spine and the stone (and note the position), then maybe add a penny to the stack to raise the back a bit farther and give you something to measure against.
 
sygyzy said:
Thanks again for all your help guys. I honestly don't know how I got that chip but that suggestion that sideways force on the board or a twist may have caused it seems the most logical. Is there anywhere I can pick up Camellia oil locally? I saw the links you guys posted but I hate ordering cheap items and paying another 50% for shipping. It'll be impossible to convince my roommate to oil it too. On second thought - I'll probably skip this step for now.

I might try your technique flatgrinder but since I don't have a spare belt lying around nor that many grits of sandpaper, I am not sure when this will happen. I hope my Norton combination stone can work for now.

I will try to increase the angle a bit. How do you guys assure the angle you are after as well as guarantee it? That is, I think most Japanese knives are about 10-12 degrees. What if I wanted 18 degrees? I could just eye ball it but each time I went back and forth on the stone I might be doing 13, 15, 17, 19, 18 degrees.

HoB - I am still learning terminology but yes, this seems to be beveled on just one side (single edge), the right side. And it is flat on the other side. It does not seem concave on the other side. It might be?

Thanks again everyone!
Click to expand...

Your knive is a right handed, chisel ground blade. Maintain the angle exactly as it is on the bevelled side and grind the flat side completely flat. Japanese sushi chefs grind their knives every morning and eventually they wear away completely where they are then buried in knife graveyards. It is true honest.

Forget Camelia Oil, use any kitchen oil. It will never be on there long enough to go rancid or conjeal. Doesn't Camelia oil smell and taste strongly of cloves?

You might find this interesting http://watanabeblade.com/english/pro/pro.htm

Here is a nice example of a chisel ground blade :)
http://www.japanese-knife.com/Merch...fe&Product_Code=HSU-HAK1033-EE&Category_Code=

And finally, sharpening Japanese blades;
http://www.japanesechefsknife.com/HowToSharpen.html
 
sygyzy,

Before you try and sharpen it, determine what kind of grind is on the blade. If it is sharpened on only one side, it's a chisel grind. Both sides, it is a convex grind.

Here's a picture of my Santoku:

IMG_0886.jpg


I just stropped it and it passed the 1" hanging rope cut with flying colors! I did it several times and it still shaves. Sure, it rusts ... but it really does hold an edge.
 
sygyzy said:
I could just eye ball it but each time I went back and forth on the stone I might be doing 13, 15, 17, 19, 18 degrees.
Click to expand...

Yes, that is what happens any time you freehand sharpen, the only real problem is making sure you don't progressively raise the angle each time to speed up the process. As long as you keep the average angle the same it is fine, the tighter you control the angle the faster the sharpening process.

-Cliff
 
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