How to Sharpen a Knife

One of the very first questions I get from a new scout is… “When can I start using a knife?”

It’s almost a right of passage for all scouts and it is a very rewarding achievement for them to be able to use wood tools, but especially that knife in camp. One of the requirements for knife safety is learning how to sharpen it because a dull knife is a dangerous knife. The idea here is that you have to put more pressure behind a dull knife to do what you have to do and therefore slipping and other accidents happen as a result of it.

There is definitely an art to knife sharpening. Some knives sharpen very easy and some knives can’t hold an edge. Some people can sharpen a knife in 30 seconds and some people have trouble after an hour of sharpening and still can’t get a proper edge. They really understand knives and why sharpening works. So to begin… lets first understand the purpose of what we are about to do.

The purpose of knife sharpening is to make it a usable tool for a certain set of tasks.

Wait… What? Why only certain tasks? Glad you asked…  Like anything, you want to use the right tool for the right job. It makes life easier and more enjoyable that way. Knife sharpening is no different. You sharpen a knife with a particular purpose in mind. For example: Scalpels are super sharp and are designed for very precision cuts of soft tissue. Try to whittle a stick with a scalpel and see how long that stays sharp. The edge of that scalpel (knife) is not meant to use on harder substances because of the type of blade and how it has been sharpened. The edge begins to break almost instantly when you try to cut harder substances and therefore becomes dull very quickly. When you want to cut harder substances (like whittling wood in this case) you want a knife that will stay sharp longer. You sharpen a whittling knife differently than you sharpen a scalpel.

There are actually two angles on the blade of the knife. The first one is the “shiny edge” that everyone can see and the second is the actual edge of the knife. Here is a diagram to illustrate my point.

Match your angles on a whetstone or oilstone appropriately. The taller the edge, the thinner it is and therefore tends to dull quicker because it’s more fragile.

The taller the actual edge of that knife is from the “shiny edge”, the sharper the edge will be but more fragile to pressure and flexing because the metal is thinner. The shorter the edge on a knife from the “shiny edge” won’t be as sharp (it’s still sharp) but can withstand pressure and flexing better which results in a sharp knife over a longer period of time of use. So how do we get that actual edge taller or shorter on that knife? Angles and consistency. By increasing the angle of the blade (about 30 degrees) to the sharpening instrument you will have a “shorter” edge. It will stay sharper longer while using it on different substances. By decreasing the angle (about 20 degrees) you will have a “taller” edge and you will have a crazy sharp knife that can do very finite tasks.

30 degree angle has a shorter, stronger edge. Will keep sharp longer while using it on harder materials.
20 degrees will give you a taller edge that is very sharp but will dull quicker when used with harder material.

A sharp knife is about a consistent, even edge on the blade.

Consistency is about applying the same angle on each side of the blade when you sharpen the knife. Sometimes it may only take a couple swipes on one side or both to bring the true edge back in the middle. If you get the true edge back in the middle then you get a sharp knife. If not, it will be dull. Your angles on each side of the knife have to be consistent to get the edge true to center.

Use the right type of sharpening instrument is the first half of the battle.

Sharpening sticks can get a dull knife sharp very quickly and are easy to use for beginners. The biggest drawback of sharpening sticks is that you only get one angle. Some sharpening sticks have different sets of rods/files for different purposes (course and fine). “Course V” sharpening sticks take more metal off the knife to get the shiny edge ready so the “Fine V”can shave the metal off the true edge. Oil stones require some practice to get good at sharpening knives on them. The biggest benefit is that you can adjust the angle for the purpose you need it. Whetstones are good for bringing rough edges true but not super sharp because the stone is rough. A rough wet stone will almost certainly devour a taller edge because of how rough that stone is. A rough wet stone is generally used for taking nicks out of the blade’s edge. A rough wet stone is perfect for axes. Oil stones bring a somewhat sharp blade to a razor sharp edge. Other sharpening tools people use are leather straps and ceramic cylinders. These bring edges on a knife that are razor thin.

The whetstone has been around for a very long time. It takes time and practice to get good using it. Sharpening sticks are a very easy tool to use and provides a consistent angle on the blade.

So lets get down to the meat on the bone for sharpening a knife properly 🙂

What is needed:

  1. Gloves are always a good thing. Leather gloves are great and it’s something that will stop or deflect a stray, slipped sharpening stroke/swipe.
  2. Safety space: There is a safety space which is called a blood circle. You must check to make sure you won’t accidentally cut anyone else if an accident occurs. This is equal to the distance you can extend out your arm with the closed knife in your hand 360 degrees around you.
  3. Something to test sharpness. This can be a stick, a piece of paper, etc
  4. The correct sharpening tool: Whetstone, oil stone, Sharpening stick
  5. Consistent angle: Decide the purpose and angle the blade appropriately. Around 30 degrees off the plane of the sharpening tool for sharp, shorter, more durable blade or around 20 degrees for a taller, sharper blade that is more brittle.
  6. Time: Take your time on this. “If you rush, you may gush (blood)”

The easiest way to sharpen a knife is with a sharpening stick. It has two rods or file edges shaped in a “V” formation for you to run the knife’s edge across. Those rods/files keeps the angle consistent on both sides of the knife’s blade. You can set it up on a table and use a simple motion to sharpen the knife. You start by placing the knife’s edge, closest to your fingers, on the two rods of the sharpening stick and pull towards you while keeping the knife straight up and down.

Holding your finger on top of the blade. Place the knife blade from the back part of the knife (close to your fingers) and pull towards you while you put a small amount of pressure on the blade.
Make sure the knife is straight up down as you sharpen on a sharpening stick.

Here is how to start sharpening a knife on a whetstone or oil stone: (There are literally a thousand Youtube videos on this.)

  1. Test the sharpness on something like paper or a stick for reference.
  2. Wet the stone (Oil for oil stones and water for whetstones.. don’t mix them up. You will ruin the stone if you put oil on a whetstone or water on an oil stone.)
  3. Hold the stone in your hand in such a way that the plane of the stone is higher than your hand or fingers.
  4. Angle your knife appropriately
  5. Push away while pulling the knife blade across the stone for one side (in a swiping/cutting motion). Do this 5-8 times per side. Now we have to do the other side. (illustration below)
  6. You can either switch hands and push away again (Safer) or you can turn the knife blade over and pull towards you while doing the same swiping/cutting motion.
  7. Take a clean cloth to wipe off the oil or grime. Always wipe from the back of the knife blade up to and past the edge. Not along the edge.
  8. Test the sharpness by testing it on what you tested at the beginning. Do not run your thumb or finger along the blade to test sharpness.
You push the knife away from the body while pulling it across the stone in a swiping motion.

There you go… Some good ways to think about knife sharpening that you can pass along to your scouts. Remember… You have to understand angles and how to achieve consistency in order to get and keep a good edge on your knife.

Good luck out there scouters!

Want to continue the conversation? Read more on the topic? Ask some questions about this? Add a comment to the bottom of the article. We reply pretty fast. Register today for your free membership on the next generation of the scouting social learning platform. Share our content far and wide! Sign up for our free newsletter to get updated material, get an insider pass to future posts, or win raffle prizes. Our next raffle for our members is a Collector’s Compass.

Follow us on Facebook:

[fblikebox id=2635]

The author, Tony Zizak, is a long time scouter, Eagle Scout, and the scoutmaster of Troop 119 Ellettsville, IN. He has been to scout camps across the country and was a certified Program Director, Aquatics Director and a Scoutcraft Director. As a youth Tony received his Vigil Honor and served as a Lodge Chief for Tseyedin Lodge #65. Reach out to him for any questions you may have on this article.

#ScoutsBSA #KnifeSafety #Scoutsandknives #TotenChit