when it comes to sharpening, woodworkers fall loosely into two groups — those who aren’t getting sharp and those who spend an inordinate amount of time getting sharp far beyond what is necessary to do excellent work. let’s talk about this. it’s not woodworking’s dirty little secret. it’s its massive open truth and either can ruin the experience for beginners and frustrate or exhaust even experienced craftspeople.
i’m a buddhist. no, it’s not a religion. it’s a philosophy — there’s no belief but that’s a topic for another day. actually, i’ve already covered it in articles many times ([most recently here]). but this isn’t about faith or really even about philosophy except the first commandment of woodworking — you must be sharp. here’s the problem with this instruction (and it’s the same problem moses and everyone following him had with “you must not murder”, by the way) — what’s sharp? well, let’s rewrite the instruction to make it a little clearer. this may sound like a masonic instruction but the masons definitely knew their trades. “you must be sharp enough but no sharper”. now that’s better. of course it demands an answer to the other question — what’s “sharp enough”? hopefully we can try to answer that, though.
what’s sharp enough?
sharp enough is the point where an edge tool (chisel, plane, saw, scraper, etc) cuts the wood easily and any improvement in cut quality is unimportant. what’s absolutely vital about this is that it doesn’t say “it’s the point where you can’t go any sharper” or “it’s so sharp you can’t improve the quality of the cut”. it’s not about getting the best possible cut or the sharpest possible tool. it’s about having a tool that’s sharp enough that spending more time sharpening it isn’t worth the effort because the improvement in quality is minimal. this is a little subjective and depends on many things. a large workpiece often has far larger tolerances for inaccuracy than a small one — if you’re framing a building, your tolerances for “sharp” might be “doesn’t feel like the dog chewed on it for long” but a jewelry box that fits in your hand might need to be smooth to the point you forget it’s made of wood. when you determine how sharp something needs to be, don’t forget you’re using a tool for a task. it doesn’t exist in a vacuum and you might need your plane to be sharper some days than others if you’re doing something very precise and small.
i guess the real question, though, is how to tell whether a tool is sharp enough. the answer isn’t theoretical. and it has nothing to do with arm hair or slicing paper or fingernails — come on, youtube, stop being silly if that’s not too much to ask. people want gimmicks. and they should be ashamed of themselves. of course content creators will do it — their audiences demand it and that’s the same as paying for it. but it’s nothing more than that. there’s only one way to see if a tool is sharp enough. no testing. no inspections. just use it. if it works, it’s sharp enough. if it doesn’t — that’s why you have the stones right there. you do have them right there, don’t you? don’t put them away. if you put away your sharpening stones, you’re not using them enough. do an hour of handwork on your bench and don’t touch the stones? shame on you. put any obstacle between you and your stones and you’ll put off using them. i know i certainly will. the longer you work with dull tools, the more time and effort you waste. so get sharp enough and do it often.
here’s a great test, though it’s not the only one. pare endgrain (it works with a chisel or plane blade). is it cutting cleanly or compressing the fibers? if it cuts well, you’re sharp enough. if it doesn’t, keep sharpening. some people will tell you to pare endgrain pine and see if that works. this is excellent advice if you happen to have a piece of pine in your shop. but i don’t work with pine or, if i can help it, any softwoods unless i’m doing rough construction work. and keeping a stash of pine around just to test blades seems … silly? yes. yes, it is. so take something that’s got endgrain, probably whatever the softest wood in your shop happens to be. pare that. it might be poplar or red oak. could be cherry. if it’ll pare that without tearout or compression, you don’t need to go cuddling the christmas tree stock. it’s good to go on anything.
everyone has their own sharpening method. this is not the only one. a lot of people say “this isn’t the best way but it’s my way” — that’s just silliness. childish self-deprecation or mock-humility. if i didn’t think this was the best way, i wouldn’t tell you. if people who say that in their articles and videos believe it’s not the best way, they should stop telling you to do it. if they think they’re doing it right, they should say it. honestly. it’s worth trying, i promise. this isn’t the only way to sharpen things but i believe it’s the best way and i have some pretty solid objective justification for it. here are my reasons.
- it’s fast.
- it’s relatively inexpensive in the longterm (though not as cheap as some others at the beginning).
- it’s repeatable.
- it takes less than ten minutes to learn to the point of expert ability.
- it’s safe enough a young child can do it — and that’s more important than you might think if you want your kids to get in the shop with you because if they can’t sharpen they can’t really do anything on their own and self-reliance with handtools is a huge part of that equation, especially as you probably don’t want to let them loose on your bandsaw when they’re seven, right?
- it’s universal — it works with all chisels and planes and i’m going to suggest to anyone who will listen they shouldn’t be sharpening their saws anyway unless saw-sharpening happens to be their hobby — oh my fuck, the ears!
- it doesn’t require any electrical equipment, though it can benefit from its addition, or running water.
- it’s (relatively) clean and can even be done completely without lubricant, though i wouldn’t recommend that.
- no animals (or asses of animals) were hurt in the creation of this process.
- it doesn’t require the acquisition or creation of specialized storage.
there are other benefits but those are the main ones. here’s one thing it’s not, though — traditional. at least not in the holistic sense. western woodworkers have used natural stones to get their tools sharp for millennia. you’ve probably seen black arkansas stones and similar things floating around very cheaply. those are usually used with oil as a lubricant and are extremely messy. they’re pretty fast and easy to use but they’re cumbersome, hard to clean and imprecise at best. yes, they’re traditional. but why are we fixated on traditions when we have better options now? you don’t light your house with gas and candles, do you? just because we work with our hands doesn’t mean we have to be obsessive about it. eastern woodworkers have spent most of that historical time using waterstones, eventually learning to make them from ceramics, though not nearly as recently as you may have been told — japanese craftspeople have been making artificial sharpening waterstones for centuries. so this is why it’s not completely traditional. but it’s a little traditional, depending on how you categorize tradition. a diamond stone on a backing is at the same time the most modern and the most ancient sharpening system. much like humans and other animals, diamonds are simple carbon compressed to be rigid and hard. we use synthetic diamonds but natural ones are exactly the same substance. putting them on a sheet of metal doesn’t really change the situation. so rubbing your tool back and forth on a truly hard substance? that seems pretty traditional to me. not that i’d care either way. but if you’re looking to justify it to yourself, it’s just a human-synthesized version of a natural substance adhered to another natural substance. this isn’t plastic or synthesized resin. it’s as synthetic as glass — artificial diamond is compressed natural carbon while glass is compressed natural silicon and the result in both cases is eminently useful.
so what is this method? let’s take it step-by step from rough to sharp. we’ll do it with a chisel but the same applies to a plane iron with no real modification. if you want to use the “coin trick” or ‘ruler trick” on your plane irons, that’s ok and i’ve explained it [in this article that pretends to be about lingerie].
when you get yourself a chisel, unless it’s a seriously good one, you’ll have some serious work to do on it. actually, even if it’s a good one you’re probably looking at at least a little time dealing with it not being quite flat. that’s ok. flat is something far easier to do for edge tools than human bodies — that’s a matter of more time in the gym than i’m prepared to spend most days.
actually, before we start in on the method, let’s talk about what sharp actually means. not in a loose sense but specificially. the edge of your tool is where the cutting happens. whether the bevel is down against the wood or up facing the sky, there is realistically only one part of the tool doing any cutting — it’s the angle where the bevel meets the flat section (we’ll call it the back but that’s sometimes a little misleading because it’s often the part held pointing forward when you use the tool… when i say “the back”, though, i mean the flat part, the side without the big bevel on the end). an “edge-tool” really is that simple. it’s just a big handle attached to a microscopic edge scratching the wood. that’s where all the business happens and that’s what you’re sharpening. when we talk about “sharpening angle”, the angle between the bevel and the back is the angle we mean. the smaller that angle, the more easily it will cut. the higher that angle, the less likely the cut will tear out. it’s a balancing act. and a lower angle dulls more quickly. for most tools, though, you can think of that angle being somewhere between 20 (at the very low end for delicate paring chisels) to about 40 (at the very high end for plane blades in high-angle frogs) degrees. measure the angle from the back to the bevel, not the other way around. it’s just easier. these are always approximate — when i say i sharpen my planes to 35 degrees, it might sometimes be 33 and other times be 38. it doesn’t matter that much. plus or minus five degrees and you won’t notice a meaningful difference in function or feel.
so what does that have to do with sharp? sharp means there is a point where the two planes intersect at an angle. a single point in two dimensions (extended into a third dimension, depth to create the edge of a blade) means you have a sharp tool. if this edge is rounded or square, it’s not sharp yet. the two planes actually have to meet. when looked at from the side, your chisel or plane iron should look like one corner of a triangle — if it looks like anything else, you’re not sharp.
so here’s the list of things you’ll need.
- three diamond sharpening stones — coarse, fine, extra-fine. these can be from any manufacturer but [i specifically recommend dmt]. why? they have an excellent warranty, good quality and reasonable prices. you can buy them from anywhere and i don’t get any commission on sales. i just think they’re the best choice. there are certainly other quality diamond stones. don’t buy cheap ones. ever. they’ll wear out in a few weeks or months and you’ll never get the money back. buy good quality ones and if you break them or wear them out quickly you’ll just end up with new stones. this isn’t a matter of “buy once, cry once” because we’re talking about something that will eventually wear and stop working but that should be years in the future. (i’ll talk about why you shouldn’t use sandpaper later — and why other types of sharpening stones are a waste of both effort and frustration.) don’t worry about what the “grit” size is on the plates. dmt calls 45-micron coarse, 25-micron fine, 9-micron extra-fine and 3-micron extra-extra-fine. unless you have a seriously-damaged vintage tool, you don’t need anything coarser than 45-micron. if you regularly restore antique tools, you might want an extra-coarse stone but realistically you should invest in a cheap bench-grinder for that kind of work. if you’re anti-electricity, though, dmt makes a 60-micron extra-coarse stone and that will rip through damaged steel almost as fast as a grinder — a cheap grinder is probably less money than the stone, though, and seeing the sparks fly is entertaining, at least to me. these stones are about sixty-five bucks each for a total of two hundred or so.
- a sharpening guide. my recommendation is again very specific. you can buy a cheap one but you’ll kick yourself for it and end up spending the money on a good one later. so you can save yourself the pain of double-spending by just getting the right one in the first place — [the veritas mk2 honing guide]. as with the stones, i make no money from you buying it. pick a dealer (or even get it used as there are occasionally people selling them as they decide woodworking isn’t their craft of choice and they part with their tools) and get it wherever you like. there are eclipse-style sharpening guides and they work fine but they take far longer to setup and are much less simple to use effectively. there is an article and an accompanying video from master woodworker bob van dyke from the connecticut valley school of woodworking about how to minimally-modify an eclipse-style guide to make it work better. if you’re going to use one of those, listen to what he has to say about them. but i’d skip the headache and just get the veritas. it’s about a hundred bucks and you’ll use it multiple times every day. woodworking is not a cheap hobby. if spending a hundred bucks on a basic tool that’s fundamental to enjoying the work is a problem, this may not be a world you want to get sucked into. this whole sharpening system can be purchased for less than three hundred dollars. if that sounds cheap, keep going. if that sounds like a lot of investment, i hope you’ve looked into the price of wood cause that table you’ve been thinking of building… let’s just say the tools are the least of your problems.
that’s it. two things (ok, four things if you count the stones separately). there’s no need for accessories or containers you have to buy or build. the whole thing can be easily used with a footprint smaller than a single sheet of paper. you’ll probably want some lubricant and i wouldn’t use water — it will make things rust. i suggest window-cleaner (ammonia-based, not vinegar-based, for fuck’s sake — if water’s going to eat your tools, vinegar will truly decimate them — great for short-term rust removal but you don’t want to let it just sit on the steel because you just won’t have any steel left if you do that for long) or rubbing alcohol because both are minimally-reactive with steel and evaporate quickly enough you won’t get rust forming where the moisture makes contact. you can have a little bowl of it but i use a spray bottle. ammonia-based cleaner usually comes in a spray bottle so that’s convenient. windex is good but a cheap version is fine as long as it’s ammonia-based. if you don’t know, sniff it (from a distance) and it’ll be obvious. if it smells like pickles, you’ve got the wrong one. if it makes your eyes twitch, you’ve probably got ammonia. yes, ammonia is toxic. no, you won’t be using enough for it to be an issue. soak your whole sharpening system in it and we’ve got a problem. but the problem then isn’t that it’s toxic (though it is) — it’s that you just created a flood situation on your bench and … well, let’s just say you’re not an idiot and i’ll assume i’m correct. a tiny spray of glass cleaner on the stone is plenty — how much would you use to clean a window that’s 10x25cm? not very much. pretend it’s a tiny window. (if you’ve never cleaned a window, please don’t share that with me — go clean some windows. your family will thank you. as will your vision.)
and here’s the procedure.
- clean all your stones and tools with lubricant before starting. this will eliminate any dirt or sharpening residue from the previous time or former use that can definitely get in the way. skip this step at your own risk. i’ve skipped it. and i’ve ended up with metal shavings that imprinted huge scratches in my tools that took ages to grind away. i don’t skip it anymore.
- spray a tiny amount of lubricant (ammonia or alcohol) on the stone you’re going to use. (do this every time — i won’t keep repeating it — before and after you put a tool on the stone. and wipe the stone when you’re finished with each tool to remove any extra metal that’s come off the tool and excess lubricant. you want the stone to be dry before and after each use.)
- flatten the back of your chisel. and i mean really flatten it. start with the coarse stone and hold the chisel with its intended-flat-side flush against it then rub it back and forth along the entire length of the stone. every ten or fifteen strokes, pick it up and look at it. the entire back (or the section you can fit on the stone, which might be about 8-10cm) should have a uniform scratch pattern without any interruption. if you can’t see it, hold it near a flashlight. when the pattern is uniform, you’re done with this stone for the moment. if it’s not, keep doing it. the first time you do it with a new (or especially vintage) chisel, this might take five minutes or longer — the cheaper the chisel, the longer it will take. i’ve done this with a few vintage ones that were truly beaten for years and, while i knew i should have just used the grinder, out of curiosity thought i’d see if it took a long time. it did. felt like ages. was about fifteen minutes, which isn’t actually all that long to take something i picked up for $2 and make it usable, i must admit. make sure you’re applying uniform pressure or you’ll just make things harder on yourself and make it take longer. you want it to be flat — press hard but try to press hard on the whole thing, not just near one edge.
- repeat this procedure on the other two stones with the back of the chisel — first fine then extra-fine. what you want is to see the coarse scratch pattern completely replaced with a new uniform pattern from each stone as you move on. the procedure is the same — wipe the tool and stone, lubricate, rub, inspect, keep going until it’s flat and occasionally wipe and relubricate to make sure you’re doing it efficiently.
- now here’s the fun part. put the chisel in your sharpening guide and adjust it. if it’s going to be a detailed paring chisel, adjust it to 20 degrees, maybe 25. if it’s going to be for regular use, 30-35 is a better angle. it’s up to you. experiment as much as you like. my recommendation is simple, though. start with a higher angle than you think you need and see if it works for you. the higher angle will mean it’s stronger and won’t need to be sharpened nearly as often so if you can do good work with it you’re more likely to be happy with a high angle. i do most of my chisels at 35 and rarely need to deviate except for the one i use for paring kumiko blocks, a 36mm chisel i keep constantly sharpened at 20 degrees — and have to constantly (yes, absolutely constantly) resharpen.
- now start on the coarse stone with the tool in the guide. use the whole stone. don’t just rub a 5cm area. go as far forward and back as the guide allows. you’re looking for a uniform scratch pattern so check every ten or fifteen strokes. don’t forget to clean and lubricate as often as necessary. you can wipe the tool and stone whenever it starts to get messy. this procedure shouldn’t get lubricant and metal shavings everywhere. it’s bad for the stone, the tool and your mental health, not to mention that stuff will soak into your bench and get all over your projects so don’t go there. one of the biggest advantages of this system is that it’s very clean and self-contained. when the scratch pattern is uniform across the entire bevel, go to the fine stone and repeat. finish by repeating the procedure on the extra-fine stone.
you’re done. don’t worry about going to the back of the chisel to remove burrs. there’s no need. as soon as it comes in contact with the wood, that’s gone and it won’t hurt anything. you don’t need to polish it or take it to a dead piece of horse’s ass. there’s no need to decimate your personal collection of arm-fuzziness or slice paper into curly strips. if you want, check it on the endgrain of whatever board you have handy. but if you’ve been watching the scratch patterns change you don’t need to check anything. it’s good. you can go to work and make some furniture.
it really is that simple. people say you can’t teach sharp and you can’t understand sharp until you have felt it. well, you might not have a good idea of what sharp is until you’ve felt it. but if you follow this procedure, you’ll get sharp. then you’ll experience it. it’s not optional. unless you’ve skipped steps or taken too little time — watch for a complete, uniform scratch pattern on all three stones, one after another — you’ll get predictably-sharp every time. no question.
how long will it stay sharp? that depends on many things. the quality of the blade, the work you’re doing, how rough you are with the tool, the ambient moisture and pressure of your shop, a thousand other tiny variables. but if you’re using good-quality a2 or pmv11 (or equivalent) steel tools, they should hold a sharp edge for absolutely ages. sharpen your chisels at 20 degrees and they won’t hold up very long but you’ve already been warned about that (a few times) and it’s sometimes worth it. use o1 steel and you’ll find they don’t last nearly as long but it’s still not going to be a sharpening excursion every five minutes. get true high-speed-steel (hss) chisels and they’ll last even longer but the sharpening process will be a lot slower.
by the way, this isn’t just how to sharpen a western chisel. if you’re sharpening a plane blade, the same procedure applies. and for japanese chisels the only difference is that when you sharpen the back you want the flat part to be everything but the hollow (ura) on the back. the rest is the same, especially the part about putting it in the guide and sharpening through the stones in order with a consistent scratch pattern.
if you have difficulty seeing the scratch pattern change, you can use a flashlight at an oblique or raked angle to the edge to make it easier to see. or you can color the whole bevel with a dark permanent marker (sharpie works but any cheap permanent marker will do just as well) and watch until that whole color disappears. i recommend coloring and eliminating the marker twice per stone because there are sometimes imperfections that creep in and it’ll really only take a few more second while you’re there for a more predictable result.
that, however, is the entire procedure. there are a few other questions to answer while i’m on the subject but if you’re already convinced this is the best approach for you to get predictably and accurately sharp, you don’t need to keep reading. you already have everything you need.
why not sandpaper?
the popularity of the “scary-sharp” method staggers me. people seem shocked it works. i’m not. of course it works. sandpaper is realistically just a diamond plate without the plate part and you’re sticking it to a plate. it’s the same procedure but with a disposable surface. the fact that it works is predictable. the fact that people like it so much is … less comprehensible.
here’s why. sandpaper is brutally expensive and you can only use it once. let’s say you buy three grits of good quality sandpaper — 800, 2000 and 4000 (loosely equivalent to the three stones we talked about). how much does that cost? well, a package of good quality automotive (high-grit) sandpaper might cost you $5. and you need three of them so that’s $15. each pack might have 5 sheets in it if you’re lucky. so $15 gets you five sharpenings. that’s not five times through all your tools. there’s no way it’s going to last that long. you might get five or six blades sharpened on a sheet of sandpaper before it’s worn out. you might get ten. but it’s not exactly a long-life thing. this is in addition to the original expense of a few granite or float-glass stones to mount them to and i’ll ignore that cost. so let’s say you get ten tools sharpened with your $15 investment. use your tools. an hour later, you probably need to sharpen that plane blade again. that’s ok. you have more sheets of paper. once you have them wet, though, that’s it. might as well sharpen a few more things but that’s the second sharpening right there. spend all weekend building in your shop? you might get that collection of three grits to last you all saturday but you’re probably going to be breaking out a new package by the second day. even if you’re not, that’s $15 every time you spend a weekend in the shop — and that’s if you’re lucky.
using high-quality dmt diamond stones will cost you about $200 as an initial investment. the guide is irrelevant to this cost because you need the sharpening guide in exactly the same way for both methods. let’s say you go to your shop to get some work done only one day a week and sharpen only five times that day — one pack of paper per grit per trip to the shop. that seems reasonable as a low-end estimate. how much will that cost you at $15/week to do it for a year? almost eight-hundred bucks. so the next time someone tells you the sandpaper sharpening thing is a way to save money, i encourage you to laugh. does it work? of course it works. is it effective? absolutely. is it cheap? well, it’s cheap in the same way buying a brand-new bmw is cheap. let’s just put it that way.
why not oilstones?
on the other end of the spectrum, oilstones really are cheap. absolutely. no sarcasm or argumentation against them on price. the problem with oilstones is twofold and if you can deal with these shortcomings you’re welcome to use them. but be aware of them before you make that investment. and be aware it’s an investment. you will have to buy the stones and the oil and while those are cheaper than diamond stones, if you get frustrated with them it’s sunk cost and you’ll probably end up with the diamond stones eventually anyway.
the first problem is that they’re messy. and this is enough to kill the deal for me. you have to use lubricant and what you end up with is a fragmentary soup on top of the stone as you sharpen. to a certain extent you get this on diamond plates but the glass-cleaner actually mitigates the issue while the oil makes it more like you’re bathing in a mud-wrestling pit with a bunch of drug-addled young adults. you might not find the mess to be as annoying as me. but i suspect you will once you realize it’s unnecessary. you’ll probably end up with your fingers covered in oil and black from the steel dust, too. that might not bother you but you might want to ask anyone significant in your lovelife if this is an issue — i suspect it might be. i don’t do messy hands. sure, i don’t mind getting them dirty if necessary. but i’m not going to go out of my way to spend my life covering them in lubricant oil.
the other problem is perhaps the one that turns most people off oilstones. they’re slower than diamond. in most cases, a lot slower. this doesn’t bother me nearly as much as the unmitigated messiness but it might be an issue for you. the difference in time i’ve witnessed is about half. most people i’ve seen make the switch do their sharpening in half the time with diamond stones. if you’re doing this on an hourly basis, saving two or three minutes every hour, every week for the rest of your career might just add up. well, it does add up. but it might add up to numbers you’ll notice.
why not waterstones?
i know what you’re thinking. waterstones were good enough for our parents and grandparents so they’re good enough for us. they built awesome furniture with them and so can we. absolutely. they work amazingly well. and good waterstones can be realistically almost as fast as diamond stones in practice. but that depends on how you look at it. and they built all that amazing period furniture (federal-style furniture isn’t my favorite but wow is it ever impressive! and those shakers really knew a thing or two about clean lines…) bathed in the flickering glow of candles and oil lamps, too. but something tells me the shakers wouldn’t have taken thirty seconds to adopt a more efficient, less messy sharpening method. they were all about doing good work, after all. and that didn’t mean using old tools just because they were old — it meant using the best tools for the job, regardless of when they were invented.
so what’s the downside to waterstones? there are three. mess, flatness and preparation. the third is the biggest one, though it is mitigated by some modern ones to a certain extent, though i’d consider those untraditional waterstones at best.
preparation in the case of most waterstones is soaking them in water. you don’t have to soak them constantly but you do have to soak them. the exception is stones like shaptons (the ones mike pekovich calls sexy and he’s not wrong about this) or sigma power select — these are artificial ceramic waterstones and they’re more like diamond plates but with weaker sharpening ability. for the more traditional ones, though, you’ll need a container to soak them in and a way to keep that water relatively clean — it will haunt you in so many ways if that water is contaminated because you’ll introduce all kinds of impurities that will damage your expensive tools, not to mention ruining the stones and causing a huge mess.
speaking of mess, you’ll get water and stone residue (not to mention steel shavings) absolutely everywhere. don’t believe me? try some traditional waterstones on your bench and see exactly how far the residue goes. no, you don’t have to be obsessive about keeping your shop clean (though i’m a teacher and i hate mess because it’s unproductive and detracts from progress). but this is messy on a scale no tablesaw or bandsaw is even without dust collection.
but the biggest turnoff for most people is that they don’t stay flat. you don’t just need to have stones. you need to flatten them. every time you use them and, if you’re sharpening a bunch of tools at once, often many times per sharpening session. your tools will dish the stones and you need something (usually a diamond stone) to bring them back to flat. which means the cost of the stones, the cost of the container, the cost of the flattening stone and … yes, again … the mess. is tradition worth that to you? perhaps. it’s definitely not worth it to me.
so you want to get sharp. go do it. get there, stop, build some shit. if any of this is unclear or you want more information, please let me know. otherwise, good luck! thanks for reading.