Micro Bevel - KOBA

Even though I have a counter that tells me how many visitors I get to my Blog every day, I never know if that is just spammers or real people. Then I get a friendly email from a person who tells me reads my Blog. That makes this all worth it to me, even if one person is out there reading my sharpening journey journal, I will continue to add to it.

So this is for Jim.

I'm going to talk about micro bevels and what I know about them.  I've learned a lot from someone that I consider a top notch sharpener and just all around great guy, Jon Broida.

Ok... what is a micro bevel and what's it for and equally as important to discuss, do we need one on our knives?

This is an Alpaca, she wasn't interested in knife sharpening at all, she lives in Vermont.




Ok...

Basically, it is a very small (micro) area of the knife that is added to the primary edge,  so if you had a micro bevel on the knife, and laid it down on the cutting board as if you were cutting, the micro bevel is what is making contact with the wood, behind the micro bevel is the primary edge, the normal cutting edge and behind that is the secondary bevel. I hope this is clear, i.e. where the actual micro bevel is. Now in the picture above it is likely on a chisel so when I explain what a micro bevel is for that will make sense.

The Japanese term for a micro bevel is a Koba so from now on let's use that term, it is cooler and just easier to type :) 

What is a Koba for:

Well the picture on my nifty new T-Shirt says it all really.  The purpose of a Koba is to give extra life (longevity) to the edge of the knife or tool. So it is a common thing for a wood worker to apply a Koba to a chisel for example, those tools have a rough go of it compared to most kitchen knives so a Koba helps.

The way it is done is pretty simple, you sharpen the knife normally and let's say you put a 20 degree angle on the kitchen knife. (20 deg is pretty standard for softer knives). All you need to do then is to raise the angle to 23-35 deg and sharpen the knife with very light passes over your highest grit stone. So you're not re-sharpening, you're just applying a very very thin (micro) edge or bevel to the knife which will add strength to the edge. 

Is it necessary on your every day knife and for the home chef, I don't really think so, you could get yourself into a routine where you re-sharpen the knife once a week on that high grit stone or whatever stone you finish your knives on,  this is the best way to keep your knife sharp. 

In Japan, where they make those beautiful, everyone wants one, hand made knives like the  Yanagiba Deba, Usuba and regular chef knives the Koba is often applied as a final stage before it is sold  to not only increase durability of the edge but to clean off any debris left by the blade smith. I'm talking any burr, wire edge, it is how they make that edge perfect in not only sharpness but it's ability to retain the edge for a longer period.

Typically we add about 3 degrees to create the bevel but I learned from the gifted one Jon that the Japanese do this at a much higher angle, 30-45 degrees and one side of the knife only. 

So again, do we need one, a Koba?

If you work in a kitchen and spend 12 hours a day with your knife as many of the great folks I have me do, then you want that knife to stay sharp for the shift. A Koba should get you through the shift. Lets say you have taken your knife to a different level by sharpening it at a much more acute angle,  15 or even 12 degrees. Perhaps it is a hard enough steel to be able to easily handle that angle but again, under heavy use that beautifully sharpened knife, the primary edge is going to be tested. So a Koba will give some relief and get one through the day. 

A Koba doesn't effect sharpness either by the way,  it strengthens the edge without any penalty to sharpness. It is quick and easy to apply but I think you need to experiment with it to see if you are getting any extra life out of the edge,

A Deba, a traditional Japanese Knife designed for cutting fish, i.e. through the bones is a knife that would benefit from a Koba. The heel area especially is subject to a lot of abuse so the Koba will obviously help there.

What about my everyday knives, the ones I sharpen 75% of the time, do I put a Koba on the edge..no I don't .  Regardless of my efforts to keep a knife sharp for as long as I can, I don't know what the owner is cutting, or how he/she is caring for the knife. Also, I think if  I sharpen a typical Henckels or Grohmann knife at 20 degrees and the person isn't going to bring it back to me for 6-12 months, the Koba is not going to make much of a difference.

Now if a Chef gives me his/her beautiful Japanese knife and I know that every 3-4 weeks I sharpen it than I will apply a Koba. 

To summarize:  to apply the Koba just raise the angle at least 5 degrees and sharpen one side of the knife, you can do both sides but only one side is necessary. Use your highest grit stone and REMEMBER to make sure that the other side of the knife is cleared of any burr raised by the application of the Koba.

I just use a very very light trailing stroke on the same stone to remove any debris, it's very quick and just takes a couple of passes. 

To summarize the summary:

Another way to look at it in reference to the steel of the knife is if you have a softer knife, 54-58 for example, like a Henckels or Wusthof,  and believe me there is nothing wrong with that level of hardness. If you do have one of these, like most people do, including myself, then one would think that a Koba would be of great benefit since the edge won' t last as long on a softer steel as it would on a  60 plus knife.  To be clear, you can apply a Koba to any of your knives, it's a 2 minute process and as I said, doesn't impact the sharpness. 

I recommend trying it out, take 2 of your knives, knives of similar hardness and put the Koba on one and see which knife lasts longer.  You need to start with two sharp knives though to make it a feasible experiment.

Now when it comes time to resharpen the knife with a Koba, you just sharpen it normally then reapply the Koba, it is such a quick process.  (So you will grind away the very small Koba on the stones and then just put it on when you are finishing up with the 3k or 5k or even 2k stone). 

I hope you find this helpful, the key is to experiment with it, the Koba can be applied and removed very easily so if you don't like it, just take it off by sharpening at your primary edge angle. 

I just wanted you to see my new bread knife, this has nothing to do with Kobas :)

The coolest serrated knife I have every seen,

The Looking Glass Edge

Most knife sharpeners, most, not all,  like to challenge themselves by creating a mirror like finish on the bevels/edge of their knife/knives.

To be clear, in my opinion, one does not need to do this to have a sharp knife but it sure does look nice and for anyone with a passion for knife sharpening, it is rite of passage so to speak, it was/is for me.

I also need to make it clear that knife sharpening is not something you peak at,  there is no summit, you improve, it's a journey with an infinite number of stepping stones.

So how do I do this and keep in mind, it doesn't always turn out the way I want it.

There are some key ingredients:

High Grit Japanese Water Stones, 8,000 and higher. Now you can get a very nice looking edge from 3,000 grit stone, it depends on several things, the type of stone, your abilities and your work on the previous stones.

Patience and Discipline - You need extreme patience when doing this and you need to be in your happy place, free of distraction. The discipline I refer to is your requirement to stick with the first stone until the job is done, I will explain more on that.

Absolutely perfectly flat water stones and near perfect bevels - You must be able to hold the angle perfectly, of course an Edge Pro or Wicked Edge will help set the stage for success but you are going to be repeating motions over and over so control is a must.

The real secret to this is knowing that the first stone you use is the most important one, it sets the foundation for all subsequent work.  This is where you patience will be tested and rewarded. 

Know that if you start with a 400 grit water stone, each stone that follows is merely refining the bevels. That 400 stone will scratch the bevels so you must continue with it until those scratches have just about disappeared. You do this by repeating the motions with less and less pressure and continuously monitoring your work. A loupe will come in handy, magnification will help you spot scratches you've missed and the entire bevel must be uniform. 

This could take an hour or more, this is the key, and you may have to walk away from the work if you find yourself slipping away and thinking about  ANYTHING other than knife sharpening.

So you select and angle and stick with it so that you are grinding from the top of the bevel or Shinogi Line right down to the edge.  The picture indicates a Back Bevel so that entire area needs to be worked on. 

Now you can create a Relief Angle or Compound Bevel by working a different angles, i.e. do the secondary bevel ( identified as a back bevel in this picture) at 15 degrees for example and just work at that angle to create your mirror finish. This doesn't sharpen the knife, it creates a Relief Face, the sharpening at the primary edge is done at a different angle, 20 degrees for example. Believe me, this is going to make your knife very sharp, think of this as extreme sharpening, it's quite effective. The beauty of it is that you don't need to work at the 15 deg angle anymore for touch ups, just the primary edge (20 deg or whatever angle you sharpened at).

I didn't sharpen this knife, I just found the picture somewhere.

Lets assume all your work is at one angle, 20 degrees to make it simple. 

Once you are completely satisfied that you have finished your work with your first stone, move on to your 1,000 grit stone. Remember that if you have left some deep scratches, higher grit stones won't remove them. So you are going to be either punished for rewarded as you move up in grit.

Use a lot of water too, it helps with the polishing and move up in grit until you are happy and every stone in your arsenal has been utilized. 

You will definitely see the bevel taking on a different look when you hit the 4,000 or 5,000 grit range.  

Now it becomes a pressure test........minimum pressure here and lots of water as you move up in grit, make sure the edge of the edge is being hit, remember you want the knife to be sharp, not just beautiful. That mercury look will come eventually and by eventually I mean it could take many many attempts but until you give it a shot you won't know. 

Remember, don't fret about this, you don't need a 5,000 grit stone to make your knife sharp and a sharp knife is really what you need and that should be your priority, learn how to make it sharp first, this Looking Glass Edge stuff can come later. 

We can talk about a third angle later on too, the Micro Bevel which is applied to the Primary Edge at an even higher angle, 30 deg for example. This "Koba" is designed to enhance edge retention, basically, get you through a shift on a knife that was sharpened at a very acute angle.


Cool eh.

Also note that a highly polished edge will mean that the knife has lost it's bite, so it will slice protein like nothing else but it could slide right over a tomato, it won't dig in unless pressure is applied. However, we can get around this, we can have both.....but that is for later. 

Do you trust me with your knives?

The biggest barrier I faced by far was having folks, especially Chefs hand me their knives to sharpen for the first time.
I had to run that gauntlet many times, and I completely understand, often, a Chef would give me one knife to do, then he/she would give me the rest.  I had to take this test and pass it several times and it is a statement to the owners how important their knives are to them.

It is a little easier now though with some of that hard work and very nice testimonials from well known chefs but I still get a little push back every now and then.

Now if a individual likes to sharpen their own knife/knives, that's cool, I will always ask what the person uses and if I think I can help out in anyway I will always make the offer.

Yanagiba - Traditional Japanese Knife

The thing with me, the difference perhaps is not just the fact that I sharpen many many knives and with each knife I improve, as with all things in life. The biggest difference, what gives me the edge over a chef who sharpens their own knives is that sharpening knives is all I do, it is all I'm interested in.

Shapton Glass Water Stones

Most chefs are so freaking busy that their knife sharpening consist of a quick, erratic and completely unfocused pass over a Steel or over a whetstone of unknown brand or even grit, it's just the stone that was in the kitchen. (I hear this often)

I don't think it is a matter of money either, it is just stubbornness  sometimes which results in the individual using dull knives, in a professional kitchen which to me is absolutely absurd.

I get some folk who show me their knife and hesitate giving it to me, despite that fact that I have sharpened for some of the top chefs in Nova Scotia and perhaps beyond that, they still are reluctant yet when I see the knife, it's damage, broken tip, chipped edge, dirty and painfully dull. I wouldn't trust my knife with them to be honest.  

I don't beg for peoples knives, Im happy to do them, it really is my passion and I'm good at what I do, but if you don't want me to sharpen your knife because you think I will ruin it, that's your choice, it's the wrong choice but I understand it. Eventually, you'll find me and remember, if you don't think the job I did was up to your satisfaction, of course you won't have to pay, in fact I will give you money to get it sharpened elsewhere if that is what you want. (that has never happened by the way)

This is a Twin Cermax, one of the hardest knives in the world, it is ridiculously hard in fact and to be honest, not easy to sharpen, it will test any water stone but I beat it and as a reward for  patience and having awesome Japanese Water Stones, I get to see one of the sharpest knives I've ever had the pleasure of returning to an owner. 

So yes, you can trust me but if you don't, I still like ya :)

I appreciate you reading my blog.

Don't hesitate to ask me any questions at sharpenerpeter@gmail.com

The Mother Load

Now when I get a bunch of knives like this, and these live in professional kitchen, I sharpen them all on one stone, then switch to the next stone and so on. The alternative is sharpening each knife separately but that would take a long time, longer than the method I use. This is roughly 4 hours of work to finish them all.

I used Shapton Glass, Naniwa Chosera and Nubatama Bamboo Japanese Water Stones.

Naniwa Chosera 1k, 2K, 3K and 5K (from Left to Right)

The fantastic Naniwa Chosera 3,000 stone. I love this stone.

My nifty new card

All the info is on the back 

Thank you for reading my Blog 

sharpenerpeter@gmail.com

You're better than you think.

If  you are reading this Blog, first of all thank you but if you are here than you have an interest in sharpening knives. This interest is strong enough to drive you here and undoubtedly to other areas on the internet.  You already have one of the key ingredients to becoming a successful knife sharpener.

You don't have to be the best knife sharpener, you just have to be able to get your knife to the point where there is an improvement in the edge, it's sharper than when you started in other words. If you do that, you are a better knife sharpener than tens of thousands of people, people who all like sharp knives but never did anything about it.

I think a lot of men would like to be able to sharpen a knife, all people like a sharp knife but I think that over the course of a life time, most men have either been interested, tried it or knew someone who could use a whetstone.  It's like a primal instinct, we are born with it.

How many people have gone out to the kitchen store and purchased a nice knife or set of knives with no thought on what to do with them in 3 months when they are dull. That sensation we feel with a dull knife is very fleeting isn't it, it soon evaporates and in no time at all, those really cool knives that you spent a lot of money on are not better than a new knife you can pick up for a dollar, I am not joking. We have all been through this. Then we go out and try different gadgets, we get lured into the packing that says "World's Best Knife Sharpener". I am not judging you, how do you think I know this?

This is what we all want to do with our knives, create an edge like the one pictured here, well I am telling you that you can do it. All you need is some courage and some water stones,  you can get your knife as sharp as heck with one stone, you can get it ridiculously sharp with three but with that one stone, you will soon be showing off your knives to your neighbours.

Remember these simple tricks of the trade:
1. Purchase a 1,000 grit water stone, or a combination stone with a coarse side and fine side, 400/1000 for example, but for learning an 800-1000 grit stone is effective and not coarse enough to do any immediate damage if you hold the knife incorrectly. Don't ever not sharpen because you are afraid of ruining the knife, because you are reading this, I'm going to assume you want to learn so get over any fears. (I can honestly say that I've never ruined a knife, and I didn't know a thing about sharpening when I started, there were no freaking computers when I started so I was on my own, just knew what my dad told me.

Soak the stone and place it on a stone holder or piece of wood so the stone is elevated slightly, you need some room to work so that your fingers, knuckles are clear of the table.

You can see this nifty stone holder from Shapton but you don't need one like this (disregard the green stone on top, I was just making a thickness comparison between the two, it is the stone holder that I want to show you here)

This stone holder cost about 18 dollars ........... pictured is the exquisite Naniwa Chosera 1k Stone....didn't come with the holder :)

Now get your knife and paint the edge, the edge of the edge, the part that is supposed to be sharp but is now dull. Remember this is just tired metal that has folded over, you are going to remove it on the whetstone, it's making the knife dull.


Hold the knife at an angle that you think is the closest match to what the original factory angle was, probably 19-22 deg.

The actual angle is not as important as you think, if it 19 or 23 deg, you can still sharpen the knife, what is important is to try and maintain the chosen angle throughout the process, one BOTH sides of the knife. This will be the first challenge, i.e. holding that angle but remember, you want to remove the sharpie mark that you placed on the edge. Just adjust the angle slightly but lifting or lowering the spine of the knife until you hit the target. You can re-paint the edge over and over as many times as you want. 

Over time, perhaps 20 knives in, you will develop a muscle memory and holding that angle will become second nature. 

DO NOT expect a razor sharp edge the first time or first 20 times, it takes a lot of practice but you need to practice. It works, if you watched the video or other sharpening videos you will be guided by these. It's just a matter of getting started and not being afraid that you are going to ruin the knife. Heck, it is dull anyway, how much worse can it get. Go slowly and keep focused.

Now what about pressure, use moderate pressure when starting, you will learn to adjust pressure as needed but to start, it is the amount of pressure applied that is going to have the most impact on how much metal is being removed from this 1,000 grit stone. So if you don't use any pressure at all, just the weight of the blade you are just moving the water and not abrading the steel. So go to pressure number one, (zero being the weight of the blade) and see how that feels, monitor the work and check the edge and see how you are doing. You'll see that there is no damage but you will see some scratches along the bevel leading down to the edge. good stuff.

Now you need to continue this motion until you have pushed that tired out metal to the other side of the knife, you will fell it over there and that is the burr. If you feel that burr, congratulations, now do the other side.  Don't sharpen one side of the knife for 20 minutes until you feel the burr, switch  back and forth until the burr forms. After you have done this, i.e. formed a burr on both sides of the knife you just need to remove it.....you need to get rid of that metal. You can do this by repeating the same motions but decreasing pressure, if you were at a pressure level 4, gradually take it down to level zero, you can feel for the absence of the burr. 

Be careful though, you've just sharpened the knife :)

Feels awesome eh.......now go do it again.

Thank  you for reading this.
Peter Nowlan

A Game of Stones

I sharpen a small Global in this video, I understand that in terms of video editing, this is not going to get me any awards, the purpose of this is just to show people how I sharpen a knife.
If you like it, thanks for watching, if you don't like it, thanks for putting up with it.

Peter