How to Sharpen a Knife | CRATEX Abrasives

Sharpening is the process of grinding or shaving off the blade to produce a new, sharp edge. After you create a sharp edge, you'll maintain and prolong its sharpness. However, due to the repeated use and honing, you'll notice that the knife holds its sharpness only for a little while or is not in full alignment, because the blade starts to get crushed or has chips in it.

You'll eventually lose the edge and you'll need to put a new edge on or re-sharpen your knife. Sharpening is usually performed every 6-12 months, but it can be done more frequently depending on how much the knife is used and the application.

The best way to test if the knife is sharp is to take a piece of paper and try to slice it while holding it up in the air. Or trying to slice through a rolled-up magazine page would also do the trick.

A dull knife is not only less attractive as a finished product but is also quite dangerous. Since it doesn’t provide clean cuts, you'll tend to apply more pressure than necessary when cutting, which can result in an accident.

In case you are not that crafty or don't have the tools, bringing your knife to a professional knife sharpener could be a good idea. This option is good for those who sharpen their blades only a couple of times a year, as the services can get rather costly in case you need your blades re-sharpened dozen times per year.

There's also a downside to using services of professional sharpeners. Namely, most of them use grinding stones that will remove much more material than necessary, which will reduce its lifespan (especially not suitable for chef knives). Besides, bringing it to a sharpener will prevent you from building a fine, strong bond with your blade, which is the whole point of the sharpening ritual – treating the knife with respect, so that it behaves better for its owner.

Namely, for most bladesmiths and knifemakers  sharpening a knife is more than creating a sharp edge on a blade. It's almost a ritualistic practice that puts one in touch with both the knife and the man as tool maker and tool user.

So, feel like you want to master the art of sharpening already? That's the whole purpose of this chapter – to provide necessary information on knife sharpening and a simple know-how.

 

Knife Sharpening Tools

There are dozens of different ways to sharpen a knife. It is typically by grinding it against hard surface, such as sharpening stone, or a soft surface that is embedded with hard particles, such as sandpaper.

There are dozens of different sharpening stones, such as Japanese waterstones (whetstones), diamond embedded stones and stones with different grit grades. Most basic ones have two sides – a rough and a fine grit. The grit sizes range from 100 to 10,000 or more grits. For those who don't know, the lower the number the coarser the grit, so you'll take more material with it. Of course, the higher the grit, the sharper the blade you'll create, but you just need far more strokes to get you there.

Whetstones can be single, double-sided or triple-sided stones with varying degrees of grit. When sharpening a knife with a whetstone, make sure you use progressively finer grits. It needs to be said that this is the most labor-intensive method, but when performed properly will yield the best results.

Diamond is the hardest naturally occurring substance and can therefore be used to sharpen almost any material (it can even be used to flatten waterstones), while ceramic sharpening rods are less abrasive, require more work, but deliver a much finer edge.

Choosing a stone is a matter of personal preference and a matter of function. If just starting, you'll need to try out a few stones to find the one that gives you the results that you are satisfied with. Just make sure you don't use cheap stones in case you are sharpening high-quality knives, but also keep in mind that there's no need to get fancy stones if you are just getting started with sharpening your pocket knife.

There are also various electric sharpeners suitable for both kitchen knives and pocket or tactical knives. The main obvious benefit of these electric sharpeners is speed (only takes a couple of minutes), but the main disadvantage is the fixed sharpening angle which won't be suitable for some specialized knives.

 

Blade Sharpening - Getting the Right Angle

The sharpness of the blade will depend on the edge angle or angle at which you hold the knife and the sharpening stone – the smaller the angle you hold it at, the sharper the knife.

Typical angles are about 20 degrees, but very sharp knives can be as little as 10 degrees. On the other hand, knives that require a tough edge may be sharpened at 25 degrees.

What does "tough edge" mean? Well, the edge and the sharpness of the knife primarily depend on the application. Namely, tougher edges are used for operations such as chopping, while thinner edges are used for more precise cuts with little pressure, like surgical ones.

For example, surgical scalpels are extremely sharp, but also so fragile that people throw them away after they become dull rather than sharpening them. Straight razors are very sharp with a small angle, and kitchen knives are less sharp and used for slicing rather than pressing.

That's why kitchen knives need to be honed on a daily basis to maintain the sharp edge. On the other hand, axes used for chopping wood are less sharp, so you'll need to regrind them daily rather than hone them.

When it comes to kitchen knives, Western-style knives are usually made of softer steel and are sharpened at 20-22 degrees. East Asian kitchen knives are usually made of harder steel and therefore, sharpened at an edge angle of 15-18 degrees.

 

Knife Sharpening Guide

Different people prefer and use different sharpening methods, but a sharpening stone provides the best edge and removes the least of material. That's why we've decided to provide an easy X step guide to sharpening knives with a whetstone.

First thing you'll need to do is get yourself a set of sharpening whetstones. There are different grits of sharpening stones and it is recommended to have at least two in your set. One should be a medium grit of about 800 and the second one a fine grit of at least 2,000.

Ultra-fine grit stones of 8,000 of more leave a mirror-like finish, which is not necessary for all professions and purposes. If you budget only allows one stone, then perhaps a stone of 1,000 to 1,200 grits would be a way to go. The stones with two sides and a coarser and finer git are also available, but they do have a poorer quality.

In any case, you will need a coarser stone called a "fixer". You'll use it to rub it on the surface of the stone before sharpening. You'll do this to create a flat surface on your stone and build up some sediment on the surface of the stone.

Tip:When buying a waterstone, always look for a large one that is at least 2 1/2" inches wide, 8" long and 1" thick.

 

For help you master knife sharpening, CRATEX came up with this easy 7-step guide to sharpening your knife.

Step 1: Get the Stones Nice and Moist

Before you begin sharpening your knife with whetstones, you'll need to submerge them in water for at least 45 minutes. If they are not properly soaked, they may become dry during the sharpening which may cause dents and scratches to your blade. You'll need to soak both sharpening stones and the fixer stone.

Step 2: Rub the First Stone with the Fixer

Take the coarser stone out of the water and place it on the counter in front of you. Now take your fixer and rub it for a while against the surface of your stone to make sure you are starting with a nice flat surface.

Return the fixer in the water container after you are done.

Step 3: Prepare for the First Stroke

Place the heel of the knife on the far edge of the stone and hold the knife at a 15-20-degree angle. You should hold the knife handle with one hand, spread the fingers of your other hand and place them on top of the blade to apply even pressure.

The trick for determining the proper angle with the matchbook applies not just to honing, but to sharpening with a stone as well. Grab a matchbook, place it on the sharpening stone backside down and lay the blade on top of it. That's about 15 degrees!

Step 4: Draw the First Stroke

After you find the angle in the proper starting position, start slowly dragging the knife over the stone in an arching motion. Never grind the blade forward but go with the direction of the blade. Apply a very gentle, firm and even pressure. It should look like this: heel to tip, from the front of the stone to the back. Don't forget about maintaining the 15-20-degree angle as you make the stroke.

There's also another way to do it: simply move the blade straight back and forth while puling the blade from one side to the other – or from heel to tip.

Step 5: Finish & Repeat

When you finish a stroke, your tip should end up touching the bottom of the stone. Lift the knife, reposition the blade and repeat.

You should start with 10-20 strokes on one side, and then do fewer and fewer strokes on each side until you are down to one stroke per side.

Step 6: Switch Stones

After you are done, you will check your blade for burrs. It's easy to determine whether you've raised some burrs or not – simply gently run your fingers along the blade and feel the burrs under your fingertips.

Wipe the blade off with a kitchen towel and proceed to the finer-grit stone. You'll repeat the whole process, starting with rubbing it with the stone fixture, and repeat the same strokes as you did before after that.

Step 7: Rinse the Blade

After you are done, rinse the blade under running water and you're done!

Just make sure you carefully dry your stones after each use. The best would be to wrap them up and keep them in a kitchen towel in a dry and grease-free place.

 

Note:After sharpening, the blade may feel like it's sharp, but it actually isn't and will become dull quite quickly. You'll need to remove the wire edge by using an abrasive and sharpen the blade in the opposite direction (or hone it) – with the edge leading.