How to sharpen a knife with a diamond stone? SwiftEdge Diamond Plate with Base

When the cuts start to drag and the tomato gets squashed by a dull knife, it is time to get serious about the idea of renewing the knife and giving the edge a real upgrade. Regardless of whether you just want to avoid tomato juice running all over the counter or if you want a knife sharp enough to split a hair in two, you have come to the right place. Here, you will learn how to get sharp knives with diamond hones, specifically SwiftEdge’s Diamond Plate set with its accompanying base. But first, some basic and absolutely necessary information about how knife sharpening works and what makes a knife sharp.

How knife sharpening works

It is important to have a thorough understanding of how knife sharpening works. If you think you have a good handle on sharpening, read on. If you are absolutely sure you understand, you can skip to the next heading.

Sharpening a knife happens by removing steel on each side of the edge to thin out the knife’s edge and make the triangle shape of the knife’s cross-section pointier at the tip until it ends in as sharp an edge as possible at the very front. Moving from being rounded, the steel shown as red in the figure below is removed to become a pointed triangle shape, as in the image.

You might have known that, but what many haven't realized is that when you remove steel from the knife's edge, it will eventually become so thin that the steel in practice bends over to the opposite side and you get a tiny edge, almost microscopic. This edge is called a "burr." This is a central part of sharpening knives.

The burr is small and difficult to see, but by running your finger across the knife, away from the edge, you can feel that a small ridge has formed on the opposite side of where you have sharpened at the very tip of the edge. If you do not feel this small ridge along the entire edge, you are not finished sharpening, and you must continue until you feel it. Only then have you sharpened the edge all the way out to the apex, i.e., right at the tip of the knife edge.

In the picture below, you see a close-up of an apex/edge tip sharpened with a 1200-grit diamond plate on the right side of the image, and the burr therefore bends toward the left. It is difficult to see with the naked eye, but your finger can feel it if you take your finger and pull from the side of the knife on the left side and up past the edge.

(from Scienceofsharp.com)

This is therefore felt on the opposite side of the side where you are sharpening and is a sign that you have finished sharpening. When the entire edge has developed a burr, it is a good indicator that you have sharpened enough. You can then switch sides and sharpen until you achieve the same on the other side, and then you can move up in grit, for example from 240 to 400, then to 800. Every time you switch sides of the knife, you remove the burr and create a new one on the other side, and as you go to finer grit, the edge becomes more refined and sharper, but there will usually always be a burr in the end.

Once you have achieved the desired fineness, you remove the last of the burr by stropping the knife back and forth on a leather strop or similar, opposite to the cutting direction. If you do not have a leather strop, for example, a newspaper, cardboard box, or an old belt can work well. Strop back and forth opposite to the cutting direction, just flat enough to hit and break off the burr.

When you have broken off the burr along the entire length of the knife blade, the edge tip is clean and even, and then it is durable and sharp. You can polish the edge in the same step if you apply polishing paste with a bit of grit to the leather strop, for example, 3000 grit, but it is not a necessity.

Tip!: Also remember that 3000-grit wax on a strop is not as coarse and aggressive as a 3000-grit hone, because it is on a soft backing, so 3000-grit wax will provide a polishing effect rather than sharpening.

How to get a sharp edge with SwiftEdge Plate from Storbua:

1. Choose the coarsest plate you have and start with that. Sometimes you can manage with a finer plate, but then the knife is actually already quite sharp, and you are just touching it up a bit, so usually, you have to start with the coarsest!
2. Place the plate in the base, or if you do not have the base, you can also place it on the side of a table.
3. You do not need any water, oil, or other mess to sharpen with the diamond systems from SwiftEdge.
4. Make your best guess as to what angle you need to hold the knife in to match the one the knife already has and set the knife edge down to the hone, or on the table, and try to rotate the knife slightly to feel when the edge lies flat against the surface.
5. To see if you are sharpening in the right place, it is quite simple to just mark the edge a bit with a permanent marker, then sharpen a little and you will see where the diamond hone removes the marker. When the marker is completely removed, you are sharpening right on the edge; if it is only sharpening at the very tip, you need to hold the knife a little flatter.
6. Work back and forth on the hone with even, large movements without changing the angle between the knife and the hone. Sharpen away the marker on all parts of the edge, and continue until you can feel the burr along the entire length.
7. Switch sides, keep the knife at the same angle, and continue on the other side with the same grit until you have sharpened the edge all the way down and achieved a burr on the other side again.
8. Then switch to a finer hone (approx. doubling the grit, e.g., 240 to 400) and continue. You do not need to go as high in grit if you just want a good functional edge, but we have diamond hones that go all the way to 3000 grit.
9. After finishing sharpening, you must strop the blade to remove the remains of the burr that have built up. This is done by stropping the knife blade against the cutting direction on a leather strop, preferably with sharpening paste on it, for example, double-sided leather strop with handle. This can also be done on a newspaper, a belt, or a cardboard box, but the best is leather with abrasive on it.

 

Tips and tricks:

1. Safety is alpha and omega. Do not bring out dull or sharp knives before the area is safe from distractions, tripping hazards, or other dangers like animals or children.
2. Often it can be difficult to know where the hone hits the steel. Use a marker to color the edge so you easily see where you are hitting, as the hone will sharpen away the marker. You can use this to know that the angle on the hone is correct, and when you have sharpened the entire edge all the way to the tip. When the entire marker is sharpened away, you have the right angle in relation to the factory edge. When the marker is gone all the way out, you know you have sharpened all the way to the edge.

 

How to get an even and correct angle on the edge?

When you use hones like this and sharpen freehand, it is essential to learn to keep the knife at the right angle at all times, but remember that there is not necessarily only one angle that is correct. The most important thing is to keep the knife at as similar an angle as possible at all times while you are sharpening. So when you decide on an angle, you must do your utmost to use the same one at all times, on both sides, and on all grits as you sharpen the edge finer and finer.

To keep a steady angle at all times, practice is what applies, but here are some useful tips to get started with as good a starting point as possible.

1. Use the angle the knife already has. All knives have an angle from the factory. This is a good starting point, but often you can sharpen it even sharper eventually. Nevertheless, it is okay to stick to the factory angle until you become a little more confident in your skills.
2. Find the angle by guiding the knife in a controlled manner down to the hone, and rotate the knife so that you feel the edge lay flat against the hone. Take a mental picture of how the knife stands, for example, how far it is between the spine of the knife and down to the hone.
3. To keep the angle even throughout the sharpening, you must use large movements from the large joints. Do not use your fingers or wrists to control the angle. Hold the knife gently but steadily. Lock your fingers, wrists, and preferably your elbows if you can, and use your back to do most of the movement; this ensures you get large, even movements without changing the angle of the knife.
4. Practice, practice, practice. With handheld sharpening, there will always be some variation, but with practice, you can become very consistent, so just keep practicing. The alternative is to take a look at an angle-guided knife sharpening system.

 

Would you rather have a sharpening system that holds a constant angle for you?

Check out SwiftEdge Cross, a diamond sharpening system with infinitely adjustable angles. Made specifically to get a perfect edge every time.

This innovative tool is not only easy to use, but it also provides an exceptional degree of control over the sharpening process, which means you get a sharper edge in an easier way. It is fully adjustable and works on all knives as long as they can be mounted (3mm thickness). Let us begin the journey toward culinary perfection and master sharp edges together!