Sharpening 101.4 – Producing a More Refined Edge

Good afternoon everyone.

The last time we talked about sharpening  I showed you how to put a quick edge on your steak knife before your steak got cold. This time around, I’m going to take you through the steps to put a more refined, sharper edge on your knives.

Why do you need a sharper edge? Won’t the quick edge I put on the steak knife work for everything?

Well, yes and no.

A quick edge on your main kitchen cutlery is better than a dull edge, but refining the edge has definite benefits. A refined edge will cut through things easier, giving you more control of the blade since you don’t have to exert as much effort. A better edge will also allow you to be more precise in your cutting, like making paper-thin slices of vegetables, or peeling the skin off of vegetables without losing half of it, or deboning meat. Since you are working on a proper cutting surface in the kitchen, a sharper edge will last longer between re-sharpenings, and will generally be quicker to sharpen because the main work has already been done. It takes more time to produce a refined edge, but it’s time well-spent.

The sharpening method you learned in Sharpening 101.3 holds true in this lesson also: in one hand holding the knife by the handle with your thumb resting on its spine, and the other hand supporting and guiding the tip, and the motion and feel of trying slice off a very thin slice of the stone. Remember: Safety Third.

Materials Needed

1. A set of three grades of stones that are about 2” wide by 8” long is what I used in this exercise and is highly recommended. If you don’t have three, use what you have. You also need to have the proper lubricant for your stones: sharpening oil for oil stones, or a water spritzer of some sort for water stones. You will need rags or paper towels for clean up.
2. A short-bladed practice knife, such as a paring knife or the steak knife you used last time.
3. A stone holder is highly recommended. It will raise the stone high enough so that you don’t constantly bang your knuckles on the table top, and also allows you to keep the proper angle to the stone through the entire stroke. I’ll talk more about this later on.
4. Your fingernail.

Setting Up

I chose to use Arkansas Washita stones this time because they are the most likely stones for you to have. They’re relatively inexpensive and will allow you to produce a very fine edge. When I dug mine out of the drawer and opened their cases, a flood of memories came back to me. I immediately pushed these out of my mind however, lest I become melancholy and lose my will, because then where would we be? No article and a lifetime of hacked up veggies and untrimmed fatty, bony meats, kitchen knives stuck in the walls and ceiling, hurled away by disgusted cooks after failing in their tasks, all due to dull cutlery. Frightening.

The first thing I discovered was a problem: the stones are quite thin, about a half-inch or so thick. Trying to use stones this thin will result in lots of frustration, because your hand will constantly be getting in your way. This is because the fingers of your hand, when holding the knife properly or even securely, are thicker than the stone. Trying to hold the knife in your fingertips in order to gain clearance is a fool’s game, as you have little leverage or control. The solution for this is an inexpensive stone holder. The one I use is from Lee Valley and it will hold an oil or waterstone up to 8 ¾” long in rubber grips and gives plenty of clearance for your hands, and also keeps the stone from sliding around so much.

Using the First Stone

The first stone we use is the soft Washita to establish an edge on the blade. Your kitchen knives most likely have a 20^o bevel, as it’s the most common for that type of knives. An easy way to position your knife blade close to that angle is like this:  the knife blade vertical to the stone is 90^o, cut that angle in half and you have 45^o, and cut that in half and you get 22½^o, which is really close to the angle that you want. Starting out with the knife in this position will make it easier for you the get the feel of taking a thin slice off the stone.

Start making slicing passes on the stone. After every 5 or 6 passes, smooth out the oil to cover the drying area of the stone, or add more oil. Make about 20 passes, then wipe off the blade and feel for the burr.

What in the Hell is the Burr?

As you grind the bevel of the blade down, the steel at the edge gets thinner and thinner, to the point where it gets so thin that it doesn’t have the strength to resist the abrasive drag of the stone and starts to fold up along the top of the edge. This is the burr, or wire edge. When the burr builds up along the entire length of the edge, the bevel is ground correctly and will produce a sharp edge once you do the same thing on the opposite bevel.

Testing For the Burr

Testing for the burr is very easy. Set the end of your fingernail on the flat of the blade on the opposite side that you’ve been sharpening and lightly rub it straight towards the edge so that it will slide off. If your nail hits an obstruction right at the edge that keeps it from sliding off, that’s the burr. If your nail slides off easily, there is no burr and you have to make more slicing passes on the stone.

Once have a burr along the entire edge of the blade, repeat the sharpening process on the other side of the blade, again until you have a burr along the entire edge.

Using the Second and Third Stones

When we move to the second and third stones, we move from sharpening to honing the edge. The second stone is the hard Washita stone, usually white in color, and the third is the extra hard Washita, which is black. You use these stones exactly like you used the first stone, making slicing passes until a burr is established on one side, then doing the same on the other side. The feel of the stones are all quite different from each other, and it may take a bit of “feeling” around with the edge of the blade to get the blade angle set up properly. Using the angle method from above will help find your honing angle.

Removing the Burr

Once you’ve finished sharpening and honing, you want to remove the final burr that’s left on the edge. The reason for this is that the burr is so weak that it can fold back over the edge making the knife perform like it’s dull, and it can also come off in your food. A tool called a strop is generally used for this task, but if you don’t have one there is an easy way to remove it using your finest stone. Make one or two light slicing passes on the stone, then flip it over and do one or two more. Check for the burr, and if you feel it, make a couple more passes on each side. When you don’t feel the burr, or if you only feel it in places, wipe the edge firmly with cutting motion on a folded up paper towel placed on the table top (don’t cut through it), and you are done.

 

When I sharpened the very dull knife shown in photo #1 using this method, it took me around 20 minutes to establish the initial burr. After that it took me about 10 to 15 minutes to hone a burr on each grade of stone. The photos show how the scratch pattern on the bevel changes with the finer grit of each stone.

Try this sharpening procedure and tell me how it did or didn’t work for you.

Note:

This time around, instead of pictures of me holding a knife in the proper orientation, I used photomicrographs of the knife bevel as I worked through the grits. The pictures aren’t of the best quality, as the digital microscope that I bought for this is a cheapie, and this kind of photography is surprisingly tricky. And time consuming. And eyeball maiming. I obviously need to work on my technique, but hopefully the concepts came across successfully. For me, seeing the effects of my sharpening techniques and the various stones on the edge close up was enlightening.

Electron micrograph courtesy of Utah State University

Recommended Accessories:

Lee Valley Sharpening Stone Holder

 Previous articles in this series:

Sharpening 101.1 – An Introduction

Sharpening 101.2 – Abrasives

Sharpening 101.3 – A Quick Edge