How To Sharpen A Knife ~ by WoodlandsTV

Transcript

Justin Sterry: We can't stress enough how important a knife is, and keeping the knife in the perfect condition. That's sharp, clean, and safe and ideally on your person; never left on the floor. It's too easy to walk away and lose it or trip over it, and if it's as sharp as the knife should be, you'll cut open your boot making it a medical issue as well. But this is how we sharpen our stones. We're using Japanese waterstones today. This is a 1/8 grit, and this is a 1/6 grit. The higher the number the more dense it is and the smoother the stone. This is a little stone called a nagura stone, which I use on the finest stone to produce a slurry which will not necessarily sharpen the knife, but it will polish the blad, giving it more edge what will retain longer.

I also have, for the machetes, an oilstone, because these knives don't need to be as sharp because they're doing a lot more blunt work. You don't want them too sharp because they'll dull too quickly and not be operational for as long.

First thing you do is soak your waterstones until they're completely saturated. You can always tell when that is, because when they're under the water the bubbles stop coming up through. There's no more air left in them.

Starting with the quarter stone first, get on as level base as you can, whether it be a rock, your rucksack, a piece of wood in this case, or a nice piece of flat ground. If you're in a base camp and you've got a box, bring it up so it's more of a natural level for the arms. But, you've got to work with what you've got sometimes, and here we are.

Checking the blade first for any grease or [indecipherable 2:15], and if you're [indecipherable 2:16] you've probably got resin on there, and any chips and nicks or any areas you need for special attention now. This one's pretty clean, as it happens.

Once you've checked that and cleaned your blade you start by putting -- this is a bevel blade -- you can put the bevel against the stone to the angle, and light pressure, but even pressure, pushing away and working it across the stone. We do this, depending on how blunt the knife is, six or seven times.

[sound of knife sharpening]

Justin: Then we repeat, pulling towards you.

[sound of knife sharpening]

Justin: Clean the blade off, leaving the slurry on the stone. This will make it more abrasive and work better and faster for you. The blade looks pretty good. You've kept the even pressure because you can see a nice glisten on it.

If there was any spots of white -- there's a little spot there, for instance, and there, you need to deal with that by re-sharpening, but once you've done this six to seven, eight ways each time, you do it again, but straight after each other in a sort of continuous. This helps keep the blade central and not going off sharp onto one side where it can taper off when you're using it as a knife.

[sound of knife sharpening]

Justin: That's good. I wouldn't clean the stone if I was sharpening another knife, because the slurry is already made for me. Clean the stone, reappraise the blade again. This is looking pretty good. And then we're going to go on to the smoother stone, and it's exactly the same. Six to seven ways one way, then the other, then alternative.

You'll see on the finer stone carbon left behind as it polishes and takes away the burr what's been reduced by the first stone. This will give you a much more refined and strong edge. Clean the edge. Looking for the dull spots.

And when you try a knife, whether it's sharp, you go across the blade, never up and down because that's where the serration motion goes and you'll cut through your thumb. And you feel the whole blade, not just one spot to make sure there's no dull patches where it may have been heavily worked if you were doing some carving, let's say.

The next procedure is the nagura stone, which is a little one. We'll make up a slurry on the board. This does two things. The slurry polishes the knife, keeping it rust free. It keeps your stone smooth, so when you sharpen you're not sharpening to a bow which will blunt it on the way up, and it also cleans the stones for you naturally.

And I'll only give this a few strokes. Of course, in a survival situation when you need some kind of shiny material to attract the helicopter you could do this to your knife as a heliograph or something, just to catch sun the sun out..

Next stage on is stropping the knife. This is actually called a birch poly. It grows on dead birch known as the strop fungus. It's got numerous uses. We'll hopefully see some later, but the one you can use it for is to remove the burrs by gently backward motion across the blade. This is called stropping.

You may not necessarily have one of these. You're next choice is your leather belt, or in this case, I've actually got a strop ready, and you do it 30 to 100 times, depending on how long you want to do it for, by pushing the knife away, but not the cutting edge, the back of the blade, for example.

[sound of stropping]

Justin: Very light pressure, and this will remove any of the microburrs that may be present.

[sound of stropping]

Justin: This is what we used to see in the old barbers. They had to keep their cutthroat razors sharp. And when you've had enough you can check the blade. See if there's any actual burrs or anything like that. Check it again, and of course, the best way of trying it, a knife, is to see if it actually does the job you want it to do.

[sound of cutting]

Justin: That's pretty good. Of course, you could always try on your arm and see if it will remove the hairs. Spot on.