Sharpening.....what is it actually?

Simply put, sharpening a knife is the process producing the finest apex possible on the knife, the Apex being the actual edge, where the two sides meet. If you put two pieces of plywood together and leaned them up against each other to form a tent the apex of course is the top, the highest point. If you shaved off that wood on both sides and kept going you could create a sharp edge.  The finer the edge the sharper the knife.

Now just because a knife has a very sharp edge doesn't mean it will cut nicely. An axe can have a razor edge but you wouldn't want to try cutting a carrot with it, the axe is too wide behind that sharp edge.  The best performers are knives that of course are not only sharp but thin enough to eliminate resistance during the cutting process.  We don't want any wedging effect, it should be a very effortless motion and in most cases it is not.  We often have to use more force than necessary and that leads to an array of things:

1. You get tired more quickly, it becomes a chore and something you just want to get it over with.
2. The increased friction makes the knife dull more quickly.

It is the abrasive properties of the water stones (whetstones) that allow us to sharpen a knife by the grinding metal away at the right angle on both sides of the knife to achieve sharpness. Naturally there are different degrees of sharpness, it takes time to create that perfect edge, make the apex absolutely precise where the two sides meet and marry them together.

You can make a knife sharp with a coarse stone,  if done properly that knife will be able to slice telephone book paper off of a 150 grit stone. In fact, the majority of the process of sharpening is done on the coarse stones, or the first stone selected.  Subsequent stones are refinement stones.

What is refinement:

In this picture, I have sharpened the knife in my usual fashion,  I commenced with a coarse stone and as you can see the edge has a lot of scratches. Now it is very sharp, it's freaking sharp but too there is just too many scratches on the bevels.....it's ugly but this is a necessary and natural part of the process......you want ugly.

As I move up in grit size and use the wonderful Naniwa Chosera 1000 grit stone for example, the repetitive motion of pushing that scratched up bevel over the 1k stone will start the refinement process, those scratches will disappear as they are removed.  The knife will get sharper and as long as the edge of the edge is being worked on it will become a really awesomely sharp knife.

Naniwa Chosera 1,000 awesome stone. 

(Now I will get pictures like the one above in different progressions, I didn't think this would turn out the way it did, I just held the camera lens up to the Loupe and shot the picture, it is better than I thought  it would be. Now if I were an intelligent man, I would have done the same thing with every stone so I will do that soon). 

Refinement continues with higher grit stones, but don't think, like I did once that the knife sharper with every higher grit. Remember that the lions share of work is done on the coarse stones and if you didn't get that knife razor sharp on that stone higher grit stones will not necessarily improve the edge.   
It is not as sharp as it could be because the edge of the edge was not met along the entire length of the blade on both sides so the optimum apex was not achieved.  This by the way is common, don't sweat it, as long as the knife is sharper than when you shorted you are getting somewhere. 

Let people like me fret and agonize over the perfectly apexed ( is that a word?) edge.

Refinement removes the scratches and if you spend enough time on the bevels and go high enough in grit you can achieve a mirror like finish. This however removes any of the "teeth" on the bevels that are necessary to give the knife "bite".

If I worked on a knife that I know was being used to cut tomatoes for example,  I could make it so refined that it would just slide over skin of the tomato. So I would sharpen it using a coarse stone, 500 girt, a medium stone, 1,000 grit and then I would jump to the final stone, 2,000, 3,000 or 5,000.  A three stone progression would leave the knife very very sharp with some micro serrations (teeth) and those bad boys would bite into the flesh of that tomato.

When starting  to sharpen a knife freehand, it is important to be patient enough to stick with the first coarse stone until the knife is sharp, at least sharp enough to slice photocopy paper without tearing it, it should push cut the paper.  Don't move to a higher grit stone until you can do that.

NOW.......you may be spot on target as far as your sharpening goes but there may be a little burr left on the edge, on one side, this is the most common issue and it is easy to remove.  (You can easily see a burr with a 15X Loupe which is highly recommended, visual inspection along  the way is a great habit to get into.) 

Some sharpeners will carefully with absolutely no pressure, run the edge of the knife over a piece of wood, a 2X4 for example, that will remove the edge.  Now I don't do that, I just use the water stone with zero pressure and trailing strokes only, like stropping, that will remove the burr. So if you think your knife is sharp but it is not cutting paper the way you think it should, check for a burr and ensure it is removed, the debris is your problem.




Although I have a gazillion water stones, the most common ones I use are the 320, 1,000 and 5,000 grit water stones, this combo will deliver incredibly sharp knives with practise (Lots of practice)

YOU need to manage expectations though, when I go out golfing I think I am going to shoot like Tiger Woods and then get frustrated when I shoot like Peter Nowlan the amateur.  Don't start your first knife thinking you will be able to perform eye surgery with it when done. In fact, as long as it is a little better that means you are doing something right.  The fact that you are even trying puts you in a class of your own. 

To sum up
Sharpening is the act of abrading metal on both sides of the knife (or edged instrument) until the apex is as fine as you can get it whether you are sharpening an axe at 35 degrees or a kitchen  knife at 15 degrees.  (You could sharpen an axe at 15 degrees but that would be a tremendous amount of grinding behind the edge and that 15 edge on an axe would be OK for chopping mushrooms or something, not wood)
Refining is the removal of the scratches on the bevels left by the coarse sharpening stones. 

I appreciate you reading this, I think it is so cool that other people read this Biog. 
Peter

Looking for Water Stones ..........:)

How I keep my knives sharp.

Hi,
Another quick video and this one is to show you how you can keep your knives sharp.
First of all, I sharpen knives, I don't create videos so if you are watching this video to look for mistakes, mispronunciations you are in luck, for example I say "knifes" instead of "knives". Believe it or not, you get nervous doing these things and I could do it all over again until it is perfect but I think it gets the point across.

I'm forcing you to watch it too by the way.

OK....so I have a different view on honing and here is why:

The edge of a knife is a delicate and thin strip of metal when it is freshly sharpened or new. When I sharpen a knife, I agonize over the angle, not the actual degree but the process of maintaining the chosen angle throughout the process...on both sides of the knife. This is not something that comes along the first time you sharpen a knife by hand, not for me anyway, it takes many many knives to develop the ability to hold an angle, whether it is 15 or 20 degrees.   My issue with a "Steel" is that the user is often just slapping the edge of the knife against the Steel, which is often of poor quality and done without regard to the angle the sharpener used.  It is a habit done by many who don't even know why it is being done, it's just something the individual has been told to do.

We know that a knife gets dull because the metal at the edge is fatigued, it rolls over and over time the entire edge is moved out of alignment, the knife is no longer functioning as it is meant to.  So a Steel when used meticulously will "push" that fatigued metal back into position, it realigns the edge.

HOWEVER,  that steel is still weaker than it was so what difference does it make if it is moved back to where it should be? It is very quickly going to move back and forth, the cycle of steeling in my opinion further weakens the steel and does not do a very good job in keeping the knife sharp. Now there are some good ceramic hones that will work but remember, the Steel is not a knife sharpener it is a knife edge maintainer.

How many times have you seen a cooking show where the chef very quickly steels the knife in his/her hand, unlike the picture above, how the hell does that individual hit the exact point on that knife and move that metal back into position?

Now I do believe with the right technique and the right Steel (ceramic) that the edge can be maintained to a point, but nobody can tell me that the metal being realigned is not weaker that it should be and this process is not going to be effective for very long.

( This is just my thinking, I do know that I am not alone though in this thought process)

So as I described in the video, why not use a water stone?

I'm telling you, I have been doing this for a couple of years now and it is simple and very effective process. Naturally one needs to do it properly but it is not difficult to learn. That one good stone is likely cheaper than a good Steel. It will also last an eternity if not dropped or abused.


I am not suggesting that you abandon you Steel, why not try both methods, pick up a 1200 King Stone or 4k Imanishi stone at Lee Valley and give it shot, see what you like best, the 2k Bester would be a good choice as well. I would not go lower that the 1200 though for honing.  You could also alternate what you use, use your steel or ceramic hone during the weekdays and on weekends use the stone to really touch that edge back up. I bet you will find that once you get the hang of it, you will be thrilled at how sharp the knife is after that very simple and fast trailing motion as seen in the epic video :)






Thanks so much for watching the video, I hope it was not too painful.

Peter

Japanese hand made knives - Steeling - Don't

Hi folks, been away for a couple of weeks, thank you for visiting my Blog and being patient.

I want to talk about steeling knives again and in particular knives that are very hard, i.e. 60 and above and these are my thoughts on it, you can disagree of course.

The majority of knives out there that we all use, Wusthof, Henckels, Grohmann are not that hard, they are around the 54-56 range which is fine and in some cases better which I will explain.

(There are a lot of varieties of Henckels and some are very hard, the higher end ones that is)

Lets take the average Henckels chef knife; I don't think I have ever seen one chipped, have a nick on the edge.  Now take a much harder knife, like hand made knife, one that has a 62-64 on the hardness scale for example,  it is very common to see the edges with little nicks in them.

The reason is that the metal, while very hard and able take a much finer sharpening angle and hold it's edge longer, is because the metal has a tendency to be brittle.   Softer knives have an edge that is more flexible, the metal that becomes fatigued doesn't break off, it just bends back and forth.

So why not steel the hard knives?

The metal at the edge of a hand made carbon knife for example is very thin, yes it is hard but it still very thin and it still gets dull and we know that a dull knife means the metal has folded over, it's fatigued and just shifted a tiny bit from centre.  Now with a softer knife, a steel can push that fatigued metal back in place, it just bends it back so to speak. However, that very hard steel on a carbon knife will not flex, it won't be pushed if you run a Steel over it, it will likely just break off so now you have a chipped edge.

So I do not recommend using a Steel on one of these knives, now a nice Ceramic "Steel" may do the trick but it is most likely going to just knock off the fatigued metal instead of realigning it.

So how do you keep a "hard" knife sharp, well the same way you should keep any knife sharp, you should hone it on a whetstone, remember you hone a sharp knife and you sharpen a dull one so you should hone the knife that has lost it's edge a little by using a fine water stone and use trailing motions, i.e. drag the knife towards you.

I will make a video of what I mean but it is very easy and it is very quick. As I have said before, think of that water stone as a rectangular Steel.

In my opinion, a ceramic is the way to go if you do Steel your European knives, MAC makes a really nice one as does Global but that one is expensive ($149.00).

You can order them online from Chef Knives to Go for 30-50 dollars too.

Ceramic hone

I still believe that unless a Steel (either steel or ceramic) is used properly it won't serve a purpose and remember it is not designed to sharpen a knife, it's purpose is to keep a sharp knife sharp, not make a dull knife sharp.

The key is to know when the Steel is not improving the edge. Picture that very thin edge and the steel along that edge becoming fatigued, how long can you just push it back into place before it just breaks off and I'm talking about any knife. It may not necessarily break off but by just pushing that tired out metal back into the right position, is it still not that tired out metal?

Hats off to folks who are meticulous with their steeling, just make sure it is done with care and not like you see chefs on TV slamming the edge of the knife against the steel.....as if that makes a difference. 

This is my "Steel" :)

Not every chipped knife of course is a result of using a Steel, far from it.  This damage could of come from someone putting it in a dishwasher, edge down but in this case, it does look like Steel damage but also, maybe just a bad batch from the factory, a heat treatment issue.

In any event, this type of damage is easy to repair and once repaired, I find the edge a little stronger and less prone to chipping/ The picture below is is of the same knife and it's larger brother which also had similar damage.

Repaired Edges 

Thanks all.