At some point in the wild, it might turn out to be essential for you to know how to sharpen a knife with a stone. A dull knife in the wilderness is like not having one at all. However, as simple as it may sound, using a stone to sharpen your blade takes some practice in order to get it right.
With the right knowledge, you could turn it into a deadly weapon. This how-to guide can be considered as basic survival knowledge that could end up being a life saver.
Choosing The Right Stone
Not every stone or rock can be used as a tool to sharpen your knife. Some might make your blade even more dull, so it is important to know which ones are the right ones.
A stone that will do the job is pretty much any stone with a flat surface, which will enable you to grind your blade across it, in a way and rhythm, explained later on. Such rocks are usually limestones, siltstones, and slate stones. These are most commonly found near streams, rivers, and lakes, below mountains, and as scree.
- Limestone: usually grey, but can be white, yellow or brown. It can be scratched easily and fizzes when it comes into contact with any common acid, such as vinegar. Breaks easily when hammered
- Siltstones: wide variety of colors, depending on what it’s made of. Scraping the surface of a silt stone will dislodge tiny silt grains or produce a white effervescent powder.
- Slate stones: mostly shades of grey, but can be red, black, purple and brown. Has very flat top surfaces.
But, as mentioned, not all stones are good for sharpening purposes. Never turn a blind eye to what you are using as your sharpening tool. Most of the rocks that you want to avoid have a very deformed look with sharp edges, like rhyolite (dark with glassy groundmass and very hard) and pumice (has a very vesicular texture, like a sponge).
You are looking for stones that have a more smoother look. But don’t rush your decision in choosing the stone. Some may look smooth and good to use, but are actually really rough and will damage your knife, like sandstone (easily identifiable by the grains of sand in its surface).
It’s not hard to recognize unusable stones, and you won’t have to, as long as you keep in mind that a knife can only be sharpened with a stone that has a flat and smooth surface. Feel the stone with your hands before using it, for better judgement.
The Sharpening Procedure
Once you’ve found a good stone, it is time to start with the sharpening. Now, the reason why you need a flat surface stone is because you will be sliding your blade across the stone’s surface, not the other way around.
This is because you’ve most likely observed people using any kind of rock and grinding it across the knife’s edge, hoping to make it sharp again. But that is likely to make your knife even more dull.
So now you are ready to sharpen up your knife.
The first thing you want to do is get your stone in a good grip so you will be able to hold it statically enough. If your rock is quite small, you’ll need to hold your stone at an angle towards your knife, because this kind of sharpening is just an improvisation. If your rock is larger, then you will need to find the right angle and rhythm in grinding your blade across it.
An extra recommendation is to apply some water or oil to the surface of the stone to improve the sharpening. The common stones that you are most likely to find in the wild work better with water.
The sharpening itself is easy and fast once you’ve caught the right tempo and rhythm. If you have the time to sharpen your knife, then you have enough time to not rush the process. You need to grind your knife across a stone under the right angle. The angle is what determines the sharpness of the blade’s edge at the end of the procedure.
You would want to start the procedure by following these steps:
- Place the heel of the blade at the bottom end of the stone, at a 20ᵒ angle. The angle will also depend on the size of the blade, but the minimum should be 20ᵒ.
- Start sliding the knife downwards in a semi-circular motion, in the direction your blade’s edge is pointing. You should visualize a 45ᵒ angle, and sweep the blade half that amount, until your knife’s top reaches the bottom end of the stone.
- Repeat the same in the opposite direction your blade’s edge was pointing previously, and don’t forget to do both sides of the blade.
- Repeat the procedure 5-10 minutes for a decently sharped knife.
It is very important to maintain the angle and rhythm of the sharpening for a good result. You might need to concentrate more than you thought you should, because maintaining the angle and the rhythm isn’t simple. Most people lose track, and in most swipes don’t get the same angle as in the previous one.
Tips and tricks:
- A good way to keep the same angle is to keep your fingers on top of your blade while sweeping it across the surface of the rock. This is easier to do when sharpening with a bigger stone.
- For a safer way to sharpen your blade, it is recommended that you repeat the motion 10 times in one direction, and 10 times in the other.
- The smaller the angle of your blade, the sharper your edge will be.
- A good way of telling is your knife sharp enough, is just slightly sliding your blade’s edge under a 20ᵒ angle across your palms, in order to feel the burr that should develop after the extra metal is removed from the blade. This means the knife’s edge will induce more friction on your hands than it did before you’ve sharpened it. If the side of the blade is smooth, then you haven’t achieved the burr yet.
- Make sure the entirety of your blade makes the equal amount of contact with the stone. You don’t want an unequally sharpened knife.
- Lock your wrists. The more you move your wrist, the more you disrupt the needed correct motion of the sharpening. The motion should start from your shoulders.
Sharpening Different Types of Knives
Not all knives deserve the same attention when it comes to making their blade sharp again. Not only do bigger knives require more patience and concentration, they may also require different styles of sharpening from smaller ones. Any style is featured by a different angle of the sharpening procedure, and a different rhythm. All this depends on the type of knife you are looking to sharpen.
Most people will carry a tactical knife with them when going out in the wild. If you are carrying a tactical knife with you, it will most certainly come in handy to know how to sharpen one, using nothing but a rock. A tactical knife can go dull quick, if overused. No matter the quality, no blade’s edge stays sharp forever.
Now, a tactical knife is almost the hardest one to sharpen properly, when using just a stone. A tactical knife’s blade is really thick, and it usually isn’t made out of common blade metal. It is way harder, when compared to the other knives. Such a knife will require special attention, if you don’t want to damage the blade, and make it even more dull than it is. For tips on how to choose the top tactical knife for you, see our must-read article on this topic.
There are different varieties of hunting knives. The most common one is probably the clip point knife. The blade’s spine is slightly curved and it looks like as if it was clipped off.
If you haven’t got a tactical knife with you, then you surely have a hunting knife. Hunting knives are easier to sharpen than tactical knives. The metal from which their blade is made of is a much lighter metal, which is not too hard to be sharpened with an improvised tool.
Hunting knives come in a wide variety of sizes. The larger hunting knives go dull more quickly, and it is always recommended that you take your time when sharpening them. Hunting knives will take less time to be sharpened than tactical knives, but you have to keep track of your sharpening style. Once again, a minimum of a 20ᵒ angle is needed for the sharpening to take effect.
Perhaps the smallest knife you would carry with you when going into the wild is a utility knife. They are mostly used for gutting, skinning and cutting plants. Utility knives take a long time to become dull because they are much smaller and aren’t used very frequently.
Be as it may, you never know when you might need to sharpen one,when stuck in the wild. The smallest knives are the easiest to sharpen. Their blade doesn’t need much time to be sharpened, but still requires attention to be done properly.
You don’t want to be too rough when sharpening smaller knives, because you can end up deforming the blade and damaging it beyond repair. This is because utility knives and other smaller knives are made out of simple metal that wears away quickly when ground across a stone’s surface.
More Useful Advice
- The main reason your knife gets dull is because you don’t holster it when you need to. Knives are rarely damaged by just overusing them. After you’ve used it, holster it, and put it around your waist, or in your backpack. Don’t leave it laying around on the ground, and don’t stab a tree to keep your knife.
- Remember that every inch of the blade’s edge needs to be equally sharped. This ain’t easy to achieve due to the fact that most knives are in odd shapes, so take some time practicing.
- Avoid using any kind of knife for sharpening or cutting wood. This is probably the worst thing you can do, and it is the quickest way to dull your knife. Only do this if it’s an absolute must.
- A good way of keeping the same angle while sharpening, is to make an improvised wedge, that is angled at least 20 degrees. That way you can be sure that the next grinding motion will be the same as the previous one, and it’s a good way to avoid an unequally sharpened edge. A wooden wedge should do the trick.
It’s not hard when you know the right way to do it. Sharpening a knife with a stone can be either the hardest thing you could try to do, or it can be the easiest and most useful thing to do.
In this article you are provided with all the information needed, to turn your knife into a deadly razor sharp weapon. The procedure of the sharpening itself is easy to remember, but it is way more essential to remember the provided tips, tricks and useful advice. For the best bushcraft tool you’ll ever need the next time you go out to camp, see our article on this topic.
When all summed up, you now have the knowledge that will let you get through the obstacle of having a dull knife in the wild. Remember: improvise, adapt, and overcome.