Here's the thing with knife sharpening: there's quite a few ways to do it. You could use a knife sharpening system, be it electric or non-electric, or you could use stones. Heck, some people even use the base of a ceramic coffee mug! The point I am trying to make here is that there are more ways than one to skin a cat. It's important that you understand this before going forward. While there are many ways to sharpen a knife, some ways are better than others. What I demonstrate below has worked well for me, and that is why I continue to use it. If you do it correctly, I am sure you will be happy with the results.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Here's What You Need
I will be using diamond stones for this sharpening instructable/tutorial. Diamond is one of the hardest abrasives, so only a few passes are required to strip steel off a dull edge. You can find these stones in various grits, ranging from extra coarse all the way to extra fine. If you're looking for quality diamond abrasives, I strongly suggest you check out DMT. They're the creme de la creme of diamond sharpeners! If you want to know more about these types of stones, then here's a detailed post you'll want to check out: https://myelectricknifesharpener.com/general/diamond-sharpening-stones-101.html
Step 2: But Wait! You Need to Understand This Before Sharpening!
Okay, by this point I will assume you've got your hands on a couple of stones. If you're unsure what grits to get, I recommend coarse, fine, and extra fine grits. These 3 should be able to take care of most dull edges. Now that that's out of the way, here's 2 things you need to understand before sharpening:
- Which Stone(s) Will You Use? - Look at your knife edge, and see what it tells you. Is it so dull that it can't even slice through the simplest of things? Like a tomato for example. If it is, then you probably want to start off using a coarse stone and make your way up to a fine/extra fine grit. If all you need is a quick touch up, then your best bet is to use a fine/extra fine grit.
- What Angle Will You Sharpen? - This can either be really obvious or extremely confusing. The obvious case is when your knife can be identified as either being a super thin Japanese style blade, or a thick Western/American style. The Japanese style blades are ground with an edge angle of 12-15 degrees, whereas the Western style is ground to 20-22 degrees. These would be the angles you would sharpen at. What about the confusing case? It's when you're unsure what your knife is! When I'm unsure of my edge angle, I typically sharpen to 15-16 degrees. And that's because I prefer having a razor sharp thin edge.
Step 3: Now We Can Finally Sharpen!
So you've figured out what stone grits you'll be using, as well as the angle you'll be sharpening. Now it's time to actually sharpen! I'll be referring to the above images as I try to explain the process.
- Reference is always 90 degrees - Hold your knife vertically such that it is perpendicular to the stone. This is 90 degrees as can be seen in figure 1. Half of this is 45 and half of 45 is 22.5. Use this as a reference/guide to find your angle.
- Always Remember, Heel To Tip! - Using the correct angle, slowly cut against the stone from heel to tip. Don't compromise form! It's better to do it slowly and correctly than doing it quickly and incorrectly. The motion should feel a little like sweeping. It should feel natural and unforced. See figures 2 & 3.
- Now Do The Other Side - Someone said it correctly that knife sharpening is all about swapping burrs. Every time you sharpen one side, you raise a burr, or a fold of metal on the other side. Then you sharpen the other side and the burr is pushed over. So all you're doing is trading burrs. Remember, what you do on one side, you do on the other! See figure 4.
Repeat steps 1-3 until you have a knife edge you're satisfied with. If it's not sharp enough, then keep going!
Step 4: Don't Forget to Strop!
You're done sharpening your knife, but there's one last thing you need to do. You need to strop. Stropping basically cleans up your edge, ridding it off any excess steel and polishing it to make it even sharper. Here's an instructable I wrote dedicated to stropping: Stropping 101. Make sure you read and understand it! I hope you enjoyed reading, and if you did, a share/favorite would be appreciated! Let me know if you have any questions.