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 ..........:)