How to Use a Knife Sharpener -ViperSharp vs Santoku

How to use a knife sharpener is a common question on Google. It’s searched for more than 3000 times per month! There must be a desire for some tutorials on the topic so I am looking to help you out. A while back I did a video on this topic using a Santoku knife. Now, you might realize that sharpening is a little different for every knife but let’s go over some of the basics here and then we can talk about specifics for the Santoku.

If you want to watch the video that shows the sharpening of the Santoku knife, you can do so right here.

Now, let’s discuss the basics of How to Use a Knife Sharpener.

First, keep in mind that a knife sharpener is a device meant to make it easier for you to keep your angle. There are many versions of this type of contraption out there on the market but we will focus, of course on using the ViperSharp. I did a lot of research and kept the desires of the knife enthusiast industry in mind when designing the ViperSharp knife sharpener. I wanted a system that made it easy for me to create the sharp edge I needed and I wanted something that was the highest quality that would last. Oh, and did I mention easy? I wanted to create something that was easy.

So, if you want to learn how to sharpen by hand, this may not be the post for you. Although, there are skills you can learn and techniques that may improve even your hand sharpening game. The rigidity of the system may help you train your hands for example to be more precise. The repetition of using a knife sharpener like the ViperSharp system may help you recognize the consistency needed in hand sharpening.

So, without further adieu (Did I just speak French?), here is the list of important factors when wondering How to Use a Knife Sharpener.

  1. Be sure to use a system that eliminates any slop
  2. Affix the blade into the clamp aligning from heel to tip
  3. Find your angle using a marker
  4. Set the angle
  5. Use back and forth passes first to create a burr
  6. Rotate knife to opposite side as needed
  7. Clear burr
  8. Move from most course desired grit to higher grits
  9. Strop blade if desired

Let’s discuss the first bullet point first. This is the entire reason I started on my journey to create a knife sharpening system. There are far too many “systems” on the market that claim to be “precision” or “guided” systems that allow unwanted movement, or “slop”. Slop happens when the machine (or hands) you are using does not keep the stone or blade completely secure and unmoving. If you are seeking a consistent edge and want to get the sharpest edge you can possibly get, the first thing that must happen is to keep every pass at the same angle. This means no slop!

How to use a knife sharpener? Align From Heel To Tip

When securing the knife in the system, make sure the front of the clamp is aligned to follow an imaginary line from the heel to the tip fo the blade. This will give you the most consistent angle along the entire length of the blade. This is a rule that will work for most blades. Of course, there may be exceptions. If you find that this method does not give you a consistent edge, try adjusting the clamp position a bit and keep testing until you are getting the angle you want from heel to tip fo the blade. In most cases, this method will be the best solution for you.

Find your angle using a marker

This tip is perhaps one of the most useful and yet one of the most simple suggestions I’ve ever heard or given. You can get real scientific if you want and you can use all sorts of fancy devices and technology these days to decide on the angle. Or, you can give it your best guess, put a little marker on the edge and start sharpening, adjusting as needed to make sure you are getting the results you desire. (Remember, sometimes the more flashy you try to get, the more dangerous it can be, No Capes!) Seriously, use this method and you will always be able to find the angle needed to match your existing edge. You will also be able to see where the factory worker may have made a mistake and you can make adjustments as needed until you are getting the results you desire.

Set the Angle

Once you have found the angle needed, set your angle. With the ViperSharp, this is done by simply tightening the thumb screw at the back of the upright assembly. This screw allows the inner riser to move up and down as needed. If you need to increase to a steeper angle, loosen the screw and raise the riser. If you need to lower your angle, loosen and lower the riser. Once you are sure of your angle, lock the thumb screw finger tight and you are ready to start sharpening.

Use back and forth passes first to create a burr

Understanding the burr is an important aspect to knife sharpening. This should happen fairly quickly when using a knife sharpening system unless you have a knife that needs extreme re-profiling. So, the next question may be how to use a knife sharpener to create a burr? Let’s start by explaining what the burr is. This is important to sharpening because it helps you “Apex” your edge. If you are not apexing, you are not sharpening. So now I have two definitions to give you. First, what is the burr?

As shown in the graphic above, the burr is “folded” over metal at the very tip (Apex) of the blade. That clarifies the second word, I hope. The Apex is where the two sides of your edge meet. This is what creates sharp. If the two sides don’t meet, the edge won’t cut. The more precise they meet, the sharper the edge. The burr is created by pulling away from the “spine” or back of the blade. This motion is what rolls the metal to create the burr. When you can feel the burr along the full length of the blade, you know you have apexed the entire blade.

You can feel the burr by pulling your finger across the underside fo the blade from Spine to edge.

Rotate the knife to the other side

You can rotate the knife during sharpening as often as you wish. Some prefer to rotate back and forth many times during sharpening and others prefer to create the burr on one side first. It really doesn’t matter what method you use. Just be sure to sharpen both sides of the blade to get that apex. One of the benefits of the ViperSharp is that you can remove the clamp without losing your angle. This makes it easy to flip the blade from one side to the other and also allows you to test and inspect the blade easily during use.

Clear the burr

Once you have verified that you have created a burr, you need to clear that burr by using forward passes only with the stones. This means you are only moving toward the blade. This action will remove the folded over metal that creates the burr but will not recreate it. Removing the burr takes you to a point where you have a sharp knife. Now you just need to refine it with the higher grit stones. You do not need to create a burr with each subsequent higher grit stone if you do not want to but it is an option if desired.

Strop to use lapping film if desired

As a final measure, you can use a leather strop or a lapping film to refine your edge even more. When using these, always pull away from the blade edge so you are not damaging the strop or lapping film. This final step will remove the microscopic burrs that are left behind from sharpening. There you have it! That is How to Use a Knife Sharpener.

If you would like to know how to sharpen a specific knife edge, contact me and I can arrange to have you send me the knife and I’ll do a video for you showing how to properly sharpen that blade.


  • Excellent! Thank you-I need this. I have 2 Vipersharps (incredible, BTW) and need to learn how to use them well.

    • I’m glad to hear that Chris. I’m looking forward to doing more tutorials and videos. Hopefully it will be helpful for many.

  • I’ve got a couple of knives with recurve blades. How do you sharpen a recurve?

    • I’ve done some videos on knives with recurve. I’ll dig them up and make a post for you but if you want clear instructions on your knife specifically, send it in to me and I’ll do a video using your knife.


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