How to sharpen a knife: it's all in the "burr"!

This is the ultimate guide on how to sharpen a knife and any blade by the way.

I researched the matter and it's NOT my own. I must pay a tribute to two persons for showing me all the details: Chad Ward and especially Ben Dale .

I say that this is the "ultimate" guide because through their links you can explore the matter more in detail if you want and this should meet the needs by large...Here I simply summarize what Ben and Chad say to save you time.

To start with, sharpening by hand using honing stones is by far more accurate than any sharpening machine. Ben says that honing should be used with WATER and not oil: water works far better.

No machine can replace the sensitivity of the human hand. However, there is a learning curve when sharpening by hand and a few rules must be respected. Sharpening is a skill to train on!

The fundamental sharpening rules are:

1. Keep the sharpening angle constant and correctly over the blade's edge!
2. Form the "burr" along the whole blade!
3. Remove the burr in the end!

This is what Chad refers to as the "strategy". You now know what to achieve when sharpening.

Let's explain rule number 1:

"1. Keep the sharpening angle constant and correctly over the blade's edge!".

The drawing below is by Ben Dale and is self explanatory.

TIP!

There are a few tricks that you can use to know if you are correctly placed on the (grinding) stone. I like the "Magic Marker Trick". It's very simple: you colour the edge of the blade with a magic marker - the pen with erasable ink which is used on white plastic boards - , say in blue, and then you pass one or two strokes with the honing stone and see if you removed all the blue colour of the marker from the edge. If positive, you are doing ok, if some colour is still present, then you are making a mistake and must correct your angle.

Ok, rule number 2 now:

"2. Form the "burr" along the whole blade!"

The following picture - taken from Chad - shows the "burr".

Chad says that "The burr is your friend. A burr, or wire edge, is a rough, almost microscopic, raised lip of metal that forms when one edge meets the other".

So, the burr is "microscopic", nearly invisible and difficult to see. But you can feel it by moving your hand ACROSS - NOT ALONG, BEWARE CUTTING YOURSELF! - the blade (see Chad's picture below).

And so here we are are, on rule number 3 on how to sharpen a knife:

"3. Remove the burr in the end"

You can finish off the burr in several ways, by using a finer stones or a ceramic stone or with a polish tape or by stropping the blade to a mirror edge.

But you MUST do it. Removing the burr makes the blade's edge stronger and so the knife itself will last longer.

No it's not over. Here are some hints that BEN gives:

• Keep things simple, sharpen kitchen knives at 17°, pocket knives at 21°, and hunting knives at 23°.
• If you have a really dull knife, start with a higher angle (e.g. 21° for a kitchen knife) then gradually lower the angle on future sharpenings.
• Do not sharpen anything except for a bread knife below 15°. The edge will be too thin and delicate.

Incidentally here is a general pattern of blades' angles:

• 24° - Hunting, Pocket and Sporting knives (THICK BLADES)
• 21° - Hunting, Pocket and Sporting knives (THIN BLADES)
• 18° - Kitchen, Fish and Meat knives (THICK BLADES)
• 15° - Kitchen, Fish and Meat knives; SCISSORS (THIN BLADES)
• 10° - Serrated knives

Following are step-by-step instructions on how to sharpen a knife.

In principle, sharpening a knife means removing metal from the blade's edge. You remove metal by grinding away the metal surface. Water helps making the abrasion caused by the movements of stone to metal more delicate and "soft", hence less deep inside the metal surface.So you should use progressive less coarser - or progressive finer stones - when sharpening. Two or three stone sizes should suffice for each kind of knives.

So, let's say that you need to have a total of 4-5 stones in your workshop plus a ceramic stone or a polish tape perhaps to finish off: a medium coarse, a fine-stone, an extra-fine, a "600" stone.

Then the stone grit depends on the kind of knife you want to sharpen . Here is what Ben suggests:

• For kitchen knifes: start with a MEDIUM stone and finish with a FINE Stone
• For pocket and hunting knives: start with a MEDIUM stone and finish with an EXTRA FINE Stone
• Going on to Polish Tape: use a 600 after the EXTRA FINE stone

"Numbers" are country sensitive. The famous japanese honing stones (used for instance in the wonderful art of the Japanese "Samurai" swords - the "Takanas") are ranked by the "thousands". It's important to keep in mind the principle of "coarse", "medium", "fine", "extra fine" and so on, I think.

TIP!

And to round off this page on how to sharpen a knife, here is what is universally recognized as best book on sharpening:

Leonard Lee: "The Complete Guide to Sharpening", The Taunton Press, 1995