How to Sharpen a Knife

A knife is perhaps the most useful tool for anyone who loves the outdoors, and learning how to sharpen a knife is an important skill that will take time to perfect. But with some practice and concentration, anyone can learn to keep their knives sharp and ready for the next cutting task. Through years of experience in my knife sharpening business, I’ve developed a system for quickly getting a sharp edge that I’ll share with you in this article. I’m going to give you a step-by-step guide for two methods of knife sharpening: First, with a traditional sharpening stone. Second, with sandpaper and a mousepad. Yes, you read that correctly, a mouse pad sharpener. 

How to Sharpen a Knife with a Stone  

There are many great knife sharpeners on the market that are easy to use and effective. But, learning how to sharpen a knife with a stone is a skill everyone should know. Now, there are many options out there for stones which range from cheap synthetic stones that wear out with one or two uses, all the way to high-end Japanese water stones that cost hundreds for each grit. For this knife sharpening tutorial, I’ll be using an inexpensive, but effective, medium natural Arkansas stone that I’ve had for years.

Read Next: Best Sharpening Stones 

What You’ll Need

Step 1: Water

I like to use water on my stones, so I begin by submerging my stone in a Tupperware container filled with water while I prepare everything else. It’s not a good idea to use a stone dry because the metal shavings will “clog up” the stone and make it ineffective. During the sharpening process you may rinse the stone and soak it again. Too much water being drizzled on the stone during the process won’t be a problem, but too little can be. Make sure your stone has plenty of water on it during the entire process.

Step 2: Marker

Take your marker and color the sharpening bevel. This will allow you to see where the stone is contacting the edge so that you don’t go too shallow or too deep. When the marker is gone, you’ll know that you’ve gotten to the apex of the edge.

Step 3: Find the Angle

Hold your knife close to the blade and lay it on the stone with the edge facing you. Place the fingers of your free hand on the spine (back/non-sharpened) of the knife and let the tips hang over and rest on the stone. Keeping your fingers on the same spot and letting them barely drag across the stone will help you keep a consistent angle until you really get the feel for it. 

Hold the knife’s spine off the stone at about a 20-degree angle. Only the edge should touch as you make a light pass starting from the knife’s tip then moving across and away on the stone until the heel touches the stone. 

Then check where the marker is worn off. If only a narrow line is worn off right at the very edge, your angle was too steep, and you need to lay the blade slightly lower to the stone. If the marker is only worn on the other side of the bevel, you were too shallow, and you need to bring the blade a little higher off the stone. Make a few passes until you find the sweet spot where the entire edge is contacting the stone, then go to Step 4. 

Tip: Finding and maintaining a consistent angle is the most difficult part of sharpening with a stone. An angle guide is a handy accessory to buy with your sharpening stone. The guide will keep your angle consistent and act as training wheels as you get used to freehand sharpening. 

Step 4: Raise a Burr

Now that you have your angle, make passes on the stone until you feel a burr on the edge. Carefully (and lightly) “wipe” your thumb or finger across the edge. Make sure the motion is perpendicular to the edge, not parallel to it. One will allow you to feel the burr, and one will likely slice you. 

It should feel “rough” going from one direction and smoother from the opposite direction. Sometimes you can see the burr. It may just look like a micro-bevel that will catch the light, but it’s a tiny “flap” of metal that has been folded over the edge. 

When the whole edge has a burr, you can go back to Step 3, and do the same thing on the other side. (When you raise the burr on the other side, the burr may begin to come off and look like a super fine piece of wire as it detaches from the edge.) For most people, the hardest thing about this process is switching hands with the knife. Training your non-dominant hand may take some time. If you can’t get the hang of switching hands, you can flip the knife over so that the edge is facing away from you, and keep it in the same hand. But this will require that you learn the motion backwards. Either way works fine as long as you keep the angle consistent.

Step 5: Refine

After you raise a burr on each side of the bevel, you will want to refine the edge. Make alternating passes on the stone, always with the blade’s edge trailing the spine. I usually do ten passes on the left, then ten on the right, then five, three, two, and one pass on each side. After that, I’ll check the sharpness by slicing a piece of paper. If it goes through it cleanly, then you’re all done. If there are some hang-ups or it won’t slice well, it may need some more refining, or you may not have raised the burr correctly.

Sharpening with a stone will definitely take some practice, and you will mess up more than once. But this is a great skill to develop that will absolutely be worth the time it takes to learn. One last note on using stones: Some people will progress through several stones to go finer and finer. If you do that, just raise a burr on both sides on each stone until your final stone. When the final grit is reached, you can raise your burrs, then refine the edge. Don’t bother refining on any stones other than your final grit.  

How to Sharpen a Knife with a DIY Sharpener: Sandpaper and Mousepad

Sharpening a knife with this sandpaper method will give you a convex edge on your knife. The good news is learning how to sharpen a knife will be easier since you don’t have to keep the angle perfect the entire time. As for the Sandpaper, I recommend the automotive wet/dry type. You can buy them in variety packs with a range of grits that will suit sharpening quite well.

What You’ll Need

• Wet/dry sandpaper ranging from 320 to at least 1000 grit
• Permanent marker
• Mousepad (bigger is better)
• Scrap of wood and glue (you’ll need a saw to trim the wood)

Step 1: Prep

Cut your scrap of wood to 3- to 4-inches wide, and as long as your mousepad. Cut the mousepad to fit the width of the wood and glue the fabric side (the surface the mouse moves on) to the wood. You can do this to both sides of the wood so it won’t slide around on your table. Having the rubber side out helps hold the sandpaper in place. I have used a general spray adhesive and had good results.  

Step 2: Marker

Just as with the sharpening stone method, I recommend using a permanent marker to mark the edge bevel on your knife. Color the whole edge bevel so that you can easily see where the paper is removing material. This will help you determine the correct angle in the next step.

Step 3: Find the Angle

The angle is slightly less important with a convex edge because the edge has a curve to it due to the flex in the mousepad base. Even if you are off by a couple of degrees, the pad’s give will cover your mistakes. Lay a piece of 600-grit paper on the block, and hold it in place with your fingertips at the bottom. Hold the knife with the edge facing you and at a 15- to 20-degree angle off the paper. Starting with the tip at the bottom corner, push the knife away from you while sweeping towards the opposite upper corner of the block. Now look at your marker to see where you’re removing material. The same adjustments apply here that I described in the sharpening stone method.

Step 4: Raise a Burr

Just as with the stone method, once you find your angle, you will make passes on one side until you raise a burr, then switch sides and raise a burr again. Don’t start with any grit lower than 320 unless you have deep chips or rolls in the blade. The lower grits will remove material quite fast, and you can mess up your blade if you aren’t careful. Also, you don’t need a lot of pressure for this method. Too much will cause a lot of deformation to the pad, and make your convex too steep. A lighter touch works best. Remember to be careful with your fingers that hold the paper. 

Step 5: Refine

Once you have raised a burr on both sides, you can change the grit and begin to refine your edge. Take the next grit and do ten passes per side (or until you have removed the scratches from the previous grit), then move up and do the same until you’ve reached your final grit, then do ten strokes on each side, and reduce the number as described in the stone method. If you go up to 2000 grit, you will start to get a mirror-polished finish on your blade. If you are diligent about maintaining your angle and hitting the apex, you will have a very sharp knife by the time you reach 2000+ grit. You can get grits of 6000 and above, which will really polish and refine your edge and I can easily get an edge that will whittle hair with this method.

Remember that using this method always requires the edge to be trailing the spine. You can’t make passes where the edge is going into the paper. That can work on a stone, but not here. Also, the paper can be taped to the edges of the wood so that you don’t have to hold it with your off-hand. I generally just hold the paper myself, but you just have to stay aware of where the blade and your fingers are. Although this method is more forgiving than a stone, a consistent angle will yield the best results.

Six Sharpening Tips 

Now that you know the basics of how to sharpen a knife, here are some tips that will help you master the skill. 

1: Don’t let your knife get dull

Letting your knife get to the point where it will hardly cut will make a lot more work for you. If you take a minute every week (or every day, depending on use) to make a few passes and keep your knife honed, you will rarely have to sharpen it. I use a leather strop once or twice a week to keep my knives in shape, and they rarely need a full sharpening like I have described here. Use a strop just like you would the sandpaper method.

2: Angle guides are your friend

A few companies have small angle guides that come with their stones that look like little wedges. These wedges are meant to help you get a feel for the angle. Most come in 17, 20, or 25 degrees. For a beginner, these can really speed up the learning process. Once you get a feel for it, you most likely won’t keep using them, but they are great aids in learning.

3: Don’t forget the belly

It can be difficult to get a consistent angle on the belly (curved portion near the tip). I overcome this by always keeping the edge parallel with the bottom of the stone. At the beginning of the pass, the knife handle will be pointing away from you so that the tip is parallel to the bottom (side of the stone closest to you). As your pass progresses, the handle will end up parallel to the bottom of the stone as you reach the straight part of the edge.

4: Take your time

Don’t sit down and try to learn this if you have a lot of other stuff to do. Set aside some time to practice this skill so you can slowly work through it and absorb what you’re doing. Trying to rush through this will frustrate you, and likely yield poor results, or injury.

5: Practice on a cheap knife

Everyone has one of those gas station knives kicking around, and they are perfect to practice on. Most come with a terrible edge anyway. If you slip and scratch the surface, you won’t be heartbroken, and if you foul up the edge, you won’t lose sleep. Once you’ve got some confidence, move up to the stuff that matters.

6: Don’t “roll” your knife

One of the most common mistakes I see is people rolling the knife at the end of a pass on the stone or paper. This will change the angle and prevent you from getting a good edge. At the end of the pass, keep the knife at the same angle and lift straight up to come back for another pass. Your wrist shouldn’t look like you’re twisting a throttle on a motorcycle at the end of the pass. Keep your wrist still. Lift your arm at the end, don’t twist or roll the knife.

Final Thoughts on knife sharpening

Although the examples used here were Arkansas Stones and Sandpaper, the same basic steps and principles can be applied to most sharpening techniques, whether they be sharpening a knife with a guided system, like a Work Sharp Knife and Tool Sharpener or a ceramic rod. You still have to establish an angle, raise a burr, and refine the edge. Learning how to sharpen a pocket knife or kitchen knife shouldn’t feel like a mystery, even if there is some art to it. Remember that perfect practice makes perfect, so take your time and focus on getting angle and technique correct, and you’ll be enjoying a sharp edge before you know it.