Let’s talk knife and ax sharpening… Why, might you ask? Because a dull knife will harm you. It takes more effort to cut through things when your knife is dull. Simple physics. The edge can’t cut through the object but at some point the pressure you’re putting on that knife will defeat the structure of what you’re attempting to cut and simply break through with all 60 lbs. of force you have pushing or, God forbid, pulling with and that blade will hit you full force and cut right through to the bone. Human flesh is very fragile, it takes an impact of less than 1 mile per hour to break skin. And that on a flat surface. A lot less when that surface is sharp. I have a sister who works admissions in the ER at a local hospital. She says they have two or three admissions a week with wounds from “dull” knives.
A dull ax or hatchet will take more effort and be less effective at the task meaning a higher cost in calories and hydration. A dull ax or hatchet also has a greater potential to glance off the tree you’re attempting to cut down and bury itself in our shin. Now wouldn’t that just make for a great camping trip.
Imagine you made it through the outbreak of Covid variant 352 that’s turning people into face eating zombies and you’re 100 meters from your camp 25 miles out in the woods just trying to survive, you know, make it through another day. Your wife and three kids are depending on you to get them through it and “Tink-thunk-AAAHHHHHH!” that dull ax just cut through your shin, shattering you fibula, and severing the muscles that pull your foot toes up. Now imagine there are no doctors or hospitals to go to anymore. No one to properly clean and debride your wounds, No one to set your broken shin. No one to reattach those tendons. You might survive the inevitable infection…
Alright… Enough preaching … you may have the soap box back now.
A wise man once said “You sharpen a knife once, you only hone the edge back on after that.” There is a lot of truth in that. When you get a knife from the factory it will be “sharp”… enough. If you want a very sharp and dependable edge you will need to re-profile the bevel, then put the proper edge on. When he said, “You sharpen a knife once, you only hone the edge back on after that.” he meant you profile the bevel once and hone, or carefully resharpen the very edge after each use.
Sharpening anything is about three things. Consistency, geometry, and stock removal. The most important being consistency. Dragging a blade across a stone to remove metal to shape, or profile, the bevel and the cutting edge. You must be consistent in the number of passes on each side. If you made 5 passes on the left side, you must do 5 passes on the right side. Also, the angle of the blade on the stone must be the same on both sides. The easiest way to find that consistent angle is to listen and hear the sound the knife makes as it scrapes across the stone. If you have the same angle of attack on the other side, it will sound exactly the same. This takes practice so don’t be discouraged if you don’t get there on your first dozen attempts.
I’ve been sharpening knives since Jr. High and I’m almost 60 now. I started with the circles, then graduated to pull back with the blade edge facing away from me, then graduated again to push out with the blade edge facing away. What I’ve found is: They all work, there is no singular method to free hand sharpen a knife that is the only, end-all-beat-all right way, or patently wrong way, or perfect way to get that knife sharp. The mission is to make this thing sharp and your preferred method, circles, push, or pull. gets the knife sharp then well done! Mission accomplished, moving on... But know that an inconsistent bevel will mean your knife will dull quicker.
IMHO The biggest downside to free hand, which is to say, having the stone in one hand and the knife in the other is your hands are never at the same exact angle as opposed to one and other so it’s impossible to get either a consistent or a flat bevel. You get a rounded bevel with a cross section like exhibit A below. Or an off angle (21 degrees on one side and 15 degrees on the other) like exhibit B below. Or any combination of the two. But if you secure a very flat stone to a solid flat surface, use consistent angles, consistent medium pressure, and a consistent number of passes on each side you can get very close to a geometrically perfect flat bevel such as shown in exhibit C below.
The arrows are pointing to the direction the blade edge will curl over (create a burr) and dull your blade. To feel the burr, hold your knife out in front of you with the blade parallel to the ground and the edge facing away from you, then slide your other hand from the back or spine of the blade outward over the edge perpendicular to the blade and you’ll feel that rough burr on one side or the other. The easy fix for the burr is to drag your knife, Edge down, pulling straight up with mild pressure, on the thigh of your jeans pushing that burr back to the edge where it belongs. This is a cheap and easy way to quickly hone your edge back on. Just be sure to not slide, or pull up, with the edge facing up. No need to slice your keg into lunch meat.
The steeper angled side of the blade (shown in exhibits A and B below) is the weak side and the steel will always curl over to the weak side. That’s why flat grind blades (Flat on one side and beveled on the other) never hold an edge beyond the end of the first week, the flat side is weaker.
There are literally thousands of stones on the market from $9.00 600 grit Arkansas soft stones, $18.00 hardware store 100 grit gray aluminum oxide, diamond grit, ceramics from 1000 to 12000 grit, polishing “paper” that run into the 20,000 grit, to the high-end Japanese whetstone sets from Japan that cover the gamut of grits. A full professional set of which can run into the thousands of dollars… But! If you can master the technique… they’re worth every penny!
Let’s not forget the dozens of systems that fix the blade in a brace, either vertically or horizontally, and utilize armature(s) holding the stone at an exact angle to the blade. For the fanatical, OCD, nut-freak-whacko, knife nuts like me these are the only way to go.
There are a lot cheaper options out there than Wicked Edge, and you do not need any of these systems to get perfect symmetrical bevels and a keen razor-sharp edge. All you need is a good stone ($7.00 to $40.00), oil or water, and practice. The following is my own shameless plug for my personal favorite system: Wicked Edge. Wicked Edge Precision Knife Sharpeners (wickededgeusa.com)
The Wicked Edge system clamps the knife in the center and utilizes two articulated armatures that use set screws to hold the armatures at specific points on horizontal braces or arms, if you will, from 15 to 30 degrees. The “stones” or blocks are diamond abrasive on a steel plate that is set in a plastic block with a hole through it that slides over the arms attached to the armature. I start at 100 grit then go through 200, 400, 600, 800, 1000, 3000, and 5000 grit (erasing the heavier tool marks of the previous grit with each progression) then the leather strops impregnated with 5-, 3.5-, 1-, and 0.5-micron polishing pastes. I get a perfect 15-degree bevel polished to a mirror finish every time. The edge lasts months with everyday light use tasks (opening packaging, envelopes, chip and cereal bags, etc)
Be forewarned… The base model first generation set (without base) with 100, 200, 400, and 600 grit blocks runs about $400.00. You can get an astoundingly sharp edge with just this. To get the full Monty, professional “Gen-3 Pro” set alone that comes with 100, 200, 400, 600, 800, and 1000 grit blocks is $1,200.00. Add in all the extra blocks running from 1200 to 3000 grit, smooth glass (for the laps), strops, laps, pastes, and emulsions will run well over $2000.00. Like I said “fanatical, OCD, nut-freak-whacko-, knife-nut”.
Because I want that exact bevel every time I sharpen, I re-profile the bevel every time I sharpen, making sharpening my EDC Benchmade Mel Pardue 3’5” 440C stainless steel blade (58-60 hardness) a three-hour process. Yes, sadly, I am that anal about my knives. Relax, we’re all hooked on something! There is no weak side to a perfectly symmetrical, geometricallt perfect bevel and edge so there is nowhere for the steel to fold over too or from . I prefer Wicked Edge but, seriously, any system that creates the perfect geometry will always give the sharpest and longest lasting edge regardless of brand, make or model. Like I said earlier, you can do it with a good flat whet stone, oil or water, and practice.
NOTE: The higher the grit number is the finer the grit or texture of the stone and the less steel it takes with every pass. The finer stones give you a smoother edge. For instance, 100 grit gives an edge that almost feels like a serrated edge and in a way it kind of is, just with tiny serrates, with 1000 grit it’s smooth like butter, with 0.5 micron polishing paste on a leather strop you can’t feel the cut. Just blood mysteriously appearing everywhere.
Another NOTE: Yes, you can use a rock you find on the ground to sharpen your knife or ax. Try to find a flat rock and if you can afford the water, use water to lubricate the stone. It’ll carry away the metal granules, so they don’t clog the pores of the stone.
Yet another NOTE: Yes you can sharpen a knife on a bench grinder or belt sander. I recommend fabricating a brace of some kind to keep you angel of attack the same on both sides. Keep a coffee can full of water close at hand and dunk the knife in it frequently to cool the blade. If the steel starts changing color (Straw, orange, blue) you’ve ruined the temper in that spot, so I’d suggest dunking the knife after every other pass or so.
A 15-degree bevel doesn’t always work on every knife. If the hardness of the steel can’t support the very fine edge, like a blade with a Rockwell hardness of 54, the edge will just flake off like dead skin. Certain steels, like AUS8, will take the good 15-degree edge but because the steel is softer the edge wears quickly. Beware of knives that claim, “Ease of sharpening coupled with good edge retention”. It’s a lie! Sharpening is wearing away of the steel just like use is wearing away the edge. If it sharpens easy, it dulls easy, it’s that simple. My personal preference is a good tool steel, D2, 15N20, 1095 with a minimum Rockwell hardness of 58-60 or 60-62 if I can find it.
Yes, like everything else, the edge on my knife will wear eventually, I use mine all the time. A few passes at 16 degrees with the 5000 grit or a ceramic rod will renew that edge quite well. Please don’t forget the most important part of the sharpening process is consistency. Maintain a consistent angle on the stone. Maintain consistent pressure on the knife. Be consistent with the number of passes on each side. Never lose sight of the goal of producing the most geometrically perfect bevel and edge possible.
Axes require a slightly different process, but the principle is the same. Stock removal to get a good bevel and good edge. First you don’t drag the ax across the stone or file, you drag the stone or file over the ax. The process of maintaining a consistent angle of the stone on ax head is no different than knife sharpening. Maintain consistent pressure on the ax. Be consistent with the number of passes on each side. A good ax will take a low degree angle, 20 to 15, well and will cut like a razor very well and will hold that edge for a surprisingly long time as long as the bevels are consistent. You will have to stop when you feel the edge start to dull, to resharpen it, which will be less often than you would with a factory edge. This is an important step with axes. A dull ax takes more strikes to get through the tree, requires more effort to make the same cut, and will take longer to get the job done leaving you tired, sweaty, and frustrated. Or worse…Tired, sweaty, frustrated, with an ax embedded in your leg or foot. Re-sharpen often.
Just like with knife sharpening, you can use any or all the stones mentioned above but we can add the trusty file for the ax. You can clamp the ax to your bench and file from the back of the ax head towards the edge being careful to maintain a consistent bevel. This is a very effective method and, depending on your file, a quick one too. You still must remember to maintain as exact an angle as possible to get a good solid consistent bevel. NOTE: When using a file keep your file card handy to clean out the metal buildup from the file.
I’ve seen a process that appears to do a good job of re-profiling the bevel and sharpening your ax or hatchet. Clamp the ax head to your bench. Roll or fold (as seen in the demonstration below) a shop towel and lay across the blunt end of the ax head then lay a file ln top of the towel and longitudinally centered on the ax head, hold the file down on the towel with one hand, then rub the other end back and forth in an arc over the edge with the other. I’ve only seen it on You Tube and haven’t tried it myself, but it appears that it should work, judge for yourself: https://www.youtube.com/shorts/VZftHckfmf0
If you have a belt sander or belt grinder you can use that to reprofile the bevel on an ax. Remember to not allow the steel to get too hot. Grind only the center 3/4 of the edge. The top and bottom edges are already properly beveled. This gentleman does a good job showing us how: https://youtu.be/B5HOCj9OotY
