Festina Lente Doors in the Palazzo Vecchio, Florence, Italy
Long-term consistency beats short-term intensity.
Bruce Lee
We have discussed many details about sharpening in this series, and while this may be the shortest article of the bunch, it is by no means the most insignificant. For some it will be the most difficult technique to master, so classical references shouldn’t prove too onerous.
If Beloved Customer pays attention to their blade’s movement when sharpening, you will notice how each reversal of direction tends to cause the bevel to rock forward and backward on the stone’s face. And what happens when we let the blade go rock-n-rolla? That’s right, the crapulous bulging bevel rears its ugly head and spits stinky sticky stuff in our eye.
Using short strokes, somewhere around 1-½ inch in length, makes it much easier to keep the blade from rocking.
A Gentle Reader named Oskar observed that, following the logic in the previous sentence, shorter strokes result in more, not less, reversals in stroke direction, and therefore shorter strokes should lead to more rocking rather than less. I concur with Oskar’s analysis and conclusion, as far as it goes, and am adding the following clarification to avoid confusion.
A short stroke produces smaller changes in the angles of one’s joints during the stroke compared to the changes during a longer stroke, making it much easier to maintain the bevel at the correct angle on the stone’s face. In other words, the angles of the joints in hand, wrist, arm and shoulder change less during short strokes than in longer strokes, making it easier to manage joints and tendons yielding greater repeatability.
In addition, shorter strokes tend to focus one’s attention on properly indexing the bevel on the stone during each individual stroke, attention that tends to wander more during long strokes. It’s that darn badger again.
Please note that this analysis is simply your humble servant’s opinion, and perhaps not a weighty one at that because I am not a physician, nor have I conducted the physiological studies and dissections upon which a rigorous opinion should be based.
I know that making short strokes feels inefficient, and it is compared to a machine, but Beloved Customer is probably not a Cyberdyne Systems product with a titanium alloy combat chassis. However, with practice, you will find you are able to increase the distance and speed of each stroke, especially as your focus and hand-soul coordination improves and your wrists and elbows relax and become trained.
Long extravagant strokes on rough or medium grit stones are for sharpening axes and kitchen knives, not chisels or planes.
The exception to this rule is the finishing stone, as mentioned in the previous article.
Festina Lente
In conclusion, and in order to improve your classical education, let’s review our latin lesson from the previous article: “Festina lente” translates directly as “make hast slowly.” It is defined in the dictionary as “proceed expeditiously but prudently.” We chose to translate the phrase as “Slow is smooth; Smooth is fast. ”
At least two Roman emperors, one Pope, and the powerful Medici family of the City State of Firenze Italy, back in the days when emperors, popes, and noble merchants had real power measured in armies they controlled and cities and continents they ruled, thought these two words important enough to include in their mottos and coats of arms. The words even appear in the original French version of the tale of the “Hare and Tortoise.”
They are also relevant to sharpening if you are clever enough to understand why.
YMHOS
Bug-nibbled woodwork in the Laurencian Library in Florence Italy with the Medici’s motto of Festina Lente and the turtle with a sail carved into it.
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Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may my food turn to ashes in my mouth (a very ancient curse indeed).
It is well with me only when I have a chisel in my hand – Michelangelo Buonarroti 1475-1564
The fool doth think he is wise, but the wise man knows himself to be a fool.
William Shakespeare, As You Like It
In the previous post in this series about sharpening Japanese tools, we looked at philosophical points such as making tools a long-term investment, as well as the upsides, downsides and causes of the beastly bulging bevel. In this part of the series, your humble servant will touch on a subject that will make thoughtful people think and unfuddle befuddled folks: The Double Bevel.
The Double-Bevel
Some people advocate creating double-bevels (primary and secondary bevels), or what is sometimes called “micro-bevels” on plane and chisel blades. Multiple bevels have three useful applications in your most humble and obedient servant’s opinion:
The first useful application is to repair a tool’s blade in the field when there is not enough time to do a proper sharpening job. For instance, if a blade dulls or chips in the course of a job, we can quickly add a secondary bevel at a steeper angle to the blade’s primary bevel in a few seconds and get right back to work, but never forget there will be a price to pay later over many sharpening sessions to restore the proper bevel, so it is only a temporary solution at best, and certainly not a useful long-term solution;
The second application is to quickly adjust a plane blade’s angle to reduce tearout immediately when proper sharpening is not possible. Once again, a lot of remedial sharpening becomes necessary afterwards. This application is usually restricted to the primary bevel, but we will look at a more esoteric and risky application below.
The third application is to efficiently restore a blade’s bevel to the correct angle in the case where pixies or our inattention has made the blade angle too shallow.
Case 3 above often goes like this: A blade that had cut well suddenly starts dulling quickly, maybe even chipping. Whiskey tango foxtrot!?!
When this happens, our Beloved Customers, being of exceptionally high intelligence, use the bevel angle gauge described in Part 11 of this series to check the bevel angle. They may discover the bevel angle has become too shallow for the wood it is being asked to cut.
We could increase the bevel angle by welding metal to the bevel and regrinding it, but such barbaric behavior would ruin the blade, so the most expedient way to correct the bevel is to add a steeper secondary bevel at the desired angle. We can grind this new bevel by hand, or by using a honing jig like the Lie-Nielson widget. I find I can apply more downward pressure using this jig to get the job done sooner and more precisely.
Honing jigs are undeniably useful, but they too often become an impediment to learning professional sharpening skills, and they are more time-consuming to use than freehand sharpening. Jigs can certainly make the sneaky snake of multiple bevels manageable, but please don’t ignore the inescapable fact that if one uses a jig properly, over multiple sharpening sessions the result will be… let me think about it…. wait a second while I make a little sketch here…. oh yea, a flat bevel. Hmmm….
Hey, I’ve got a crazy idea: When performing routine sharpening (not the 3 cases listed above), instead of taking shortcuts and adding micro-bevels which turn into secondary bevels and maybe even bulging bevels, why not start with a flat bevel and keep it flat? And then just maybe we could take advantage of the natural indexing properties of that flat bevel to sharpen freehand and save a lot of time NOT setting up honing jigs, or polishing skinny secondary bevels or fat bulging bevels? You know what, it just might work!
A honing jig is very helpful for making big angle corrections. I own several, but the Lie-Nielson model is my favorite: I use it every third blue moon. If you decide to use one, however, reserve it for emergency or drastic measures. Don’t let it become training wheels, kiddies.
The Nano-bevel
In this and previous posts we discussed bulging bevels, which are convex bevels on plane or chisel blades; secondary bevels and double bevels, which are additional bevels; and micro-bevels, which are a tiny secondary bevel. But there is another type of secondary bevel a clever Beloved Customer called a “nano-bevel.” I like this term and so will use it, but I caution you that, like all secondary bevels, you should employ this bevel judiciously.
We will go into freehand sharpening techniques in greater detail in future posts, but to avoid confusion when discussing the nano-bevel, we need to touch on some of those techniques now.
You may have noticed that, when sharpening freehand on every stone but the finish stone, most, but not all people do a better job by applying downward pressure on the blade only on either the push stroke away from their body or the pull stroke back towards their body, but not in both directions. This is because placing downward pressure in both directions tends to make the blade rock resulting in a less-than-flat bevel, or Saints preserve us, the barbaric bulging bevel. As you can imagine, if this rocking motion gets out of hand on the rougher stones the bevel angle can get out of control quickly resulting in unsightly bulges even the best elastic girdle can’t conceal.
However, on the finish stone, it is most efficient to apply light downward pressure in both directions. The advantage is that a teeny tiny bit of rocking helps to ensure the last few microns of the blade’s cutting edge are thoroughly polished. And because the abrasive power of a finish stone is so small, there is no danger the bevel will become rounded, at least if you don’t get carried away. From the wood-shaving’s eye view, this creates a tiny bevel at the last few microns of the cutting edge. This is one example of a “nano-bevel.” Stropping produces the same result on a larger scale.
There is also another type of nano-bevel for emergency use.
When using a finish plane on wood with twisty grain you have no doubt experienced frustrating tearout. The usual litany of solutions is to reduce the blade’s projection for finer depth of cut, skew the plane, oil and adjust the chipbreaker, resharpen the blade, adjust the plane’s sole and mouth, or even slightly dampen the wood with a planing fluid such as water, whiskey, or unicorn wee wee. All these methods can help.
Emergency Nano-bevel Modification
Another classic solution to reduce tearout of course is to use a plane with a steeper blade bedding angle, but what to do if you don’t have a high-angle plane handy?
A traditional, jobsite-expedient solution used by Japanese woodworkers is to create a nano-bevel on the ura side of the blade. This is accomplished during sharpening while polishing the ura on the finishing stone by lifting the head of the blade just a itsy bitsy teeny weeny nat’s buttfuzz thickness during the final stroke, pulling the blade towards you, of course, creating a “nano-bevel” on the last few microns of the cutting edge at the ura, effectively changing the approach angle of the blade.
Be forewarned that this is only for emergency use, and that if you overdo it, or do it too often, the nano-bevel will become a microbevel in a bad location, your blade will be damaged, efficient sharpening will become impossible, the chipbreaker will cease to function, and the gods of handsaws may curse you so all your hair falls out and your dog barfs on your shoes! Or is it your dog’s hair will fall out and you will barf up shoes? I forget.
Now where did I put that jar of planing fluid….?
Planing Fluid
Allow me to explain what “planing fluid” is and why I use it. This term refers to moisture applied to the surface of the wood to reduce tearout when planing by either hand or machine.
The good Lord designed trees to move water from the ground into the sky, so wood loves water. When a tree is cut down it immediately begins to loose cell water making the wood lighter in weight and much harder and stiffer structurally. But it still loves water.
If we apply a little moisture to the surface of a board the wood’s fibers become slightly softer, more flexible and less likely to develop tearout when planed, at least temporarily. The moisture is usually applied with a damp rag. Not too much, now!
Regarding the moisture source, water works well and is priced right, but it may dry slowly and produce inconvenient side effects. Unicorn products are dreadfully expensive nowadays, even on Amazon, so I prefer a smooth, inexpensive, industrial-grade busthead. Please ask Ken Hatch for a demonstration and recommendations for a good planing fluid next time he invites you over to his house for his world-famous tacos.
Please note that I don’t drink any planing fluid other than water. Of course unicorn wee wee is more addictive than OxyContin and drives mortals quite mad. And alcohol is yeast pee pee and deadly, but I prefer whiskey for a number of reasons.
Whiskey has a good water/alcohol ratio that wets the wood about the right amount and then evaporates cleanly. Too wet and it penetrates too deeply and can discolor the wood. Too dry and it evaporates too quickly.
I used Isopropyl alcohol when living in the US where it is dirt cheap, but it is considered a pharmaceutical in Japan and so is very expensive, another convenient case of collusion between manufacturers, retailers and government to fix prices. As with other alcohol products not intended for internal consumption, it contains actual poisonous additives demanded by greedy governments for the sole purpose of maximizing tax revenues. I don’t need those poisons touching my tools or my skin. Cheap whiskey, however, doesn’t contain such poisons (other than alcohol, of course), it’s cheaper and smells better.
Conclusion
A wise man will seek to avoid shortcuts that save a bit of time short-term only to waste more of his time and money long-term. If you simply make the effort to invest in basic sharpening skills, pay attention, and keep the bevel flat, time, steel, and stone-wasting monkeyshines such as double bevels will be unnecessary.
We have talked about the cutting edge’s proper shape. Beginning with the next post in this series, we will examine how to use sharpening stones to make it that way.
YMHOS
Well dudes and dudettes, I’m done sharpening using my most excellent honing jig for now and am off to the beach! Don’t wait up.
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may my blade bevels multiply exponentially.
Shall I compare thee to a summer’s day? Thou art more lovely and more temperate: Rough winds do shake the darling buds of May, And summer’s lease hath all too short a date; Sometime too hot the eye of heaven shines, And often is his gold complexion dimm’d; And every fair from fair sometime declines, By chance or nature’s changing course untrimm’d; But thy eternal summer shall not fade, Nor lose possession of that fair thou ow’st; Nor shall death brag thou wander’st in his shade, When in eternal lines to time thou grow’st: So long as men can breathe or eyes can see, So long lives this, and this gives life to thee.
William Shakespeare, Sonnet 18
Your most humble and obedient servant began this post with the elegant sonnet quoted above, indisputably one of the most beautiful pieces of poetry ever written in the English language, instead of the usual pithy proverbs of Red Green, that towering Canadian Philosopher-Handyman and erudite Leader of Possum Lodge, just to show Gentle Readers how refined we at C&S Tools can be when no one is watching (ツ). But sadly we must now pause all such elegant distractions for a time to focus on the nuts-and-bolts of how to true the ura of a Japanese woodworking blade, the first step in making it sharp.
This tutorial is rather wordy because Beloved Customers sometimes find the task of managing the ura difficult at first. Indeed, while truing the ura of Japanese chisels and planes is a simple task, it’s one many get wrong the first time, occasionally resulting in emotional damage to both blade and it’s owner. I know it almost drove me non compos mentis the first few times I tried, but now that my psychiatric team has stumbled onto the right mix of meds, and Doctor Alonzo has released your humble servant from that unflattering canvas straight jacket, Beloved Customers have the opportunity to learn from my mistakes. Rejoice!
This is the first article in the series where we actually turn steel to mud, so let’s get to it.
Important GeneralPrinciples
All standard chisel blades and plane blades, whether Japanese or Western, need to have a planar “flat,” as it’s called in Western chisels or “ura,” in the case of Japanese chisels and planes opposite the bevel. When sharpening such blades it’s ideal for these areas be in contact with sharpening stones over their full width, and ideally, full length. Perfection is not necessary, however, so don’t let yourself become obsessive; That way lies madness.
A few lost souls mistakenly assume (just before they go barking mad) that the lands surrounding the hollow-ground uratsuki must be perfectly planar for the chisel to function, but such is not the case. Granted, it does make it easier to sharpen the blade, but it need not be achieved immediately, especially since a planar ura can be easily obtained gradually over multiple sharpening sessions.
If Beloved Customer’s chisel does not have a fully-planar set of lands surrounding the hollow-ground uratsuki when new, understand that it may be a hand-forged, hand-shaped, hand-sharpened tool with imperfections, and perhaps not a CAD-CAM designed, mass-produced, chisel-shaped, sharpened screwdriver. If so, please understand that this is not an aberration but is normal. However, if such natural irregularities distract to the point your eye starts twitching like that of Chief Inspector Dreyfus after spending time with Inspector Clouseau, perhaps hand-forged tools are not your cup of tea.
Procuring Perfect Tools
The previous sentence may seem to suggest that we at C&S Tools prefer to not provide our humble tools to perfectionists, but that is not the case. Rather, we insist Beloved Customers seeking the perfect chisel, plane, saw or knife adjust their expectations for perfection to match their expectations for financial outlay and fabrication time. What conditions? First, multiply your tool budget at least tenfold (seriously) and set aside that budgeted amount in hard cashy money, maybe in a thick roll in your sock drawer. You see, unlike your unworthy servant who many assume works for free, craftsmen with the skills required to produce perfect tools, and who are willing to invest their valuable time in doing so, are in high demand and do not work for free. If this seems steep, then perfection is not for you.
Next, plan your order carefully, and perhaps commission drawings. Not as easy as it sounds, mayhap.
Finally, steel yourself to wait a minimum of two years for the work to be completed, for you see, while many desire perfect tools and are willing to pay the price, you don’t need toes to count the number of overworked craftsmen that can actually forge them nowadays.
Oh yes, I almost forgot one thing. In the case of our Perfect Tool Blackmith, he has an unusual condition, one based on valid reasons I cannot disclose, that the recipient be a working professional craftsman, not an amateur, hobbyist or collector.
An option to having a perfect chisel custom-forged new is to seek out a genuine Hidari-no-Ichihiro chisel because the Yamazaki brother’s products, though very expensive back in the day and more expensive now, were pretty close to perfect in shape and appearance. But beware counterfeits.
On the other hand, the tools we sell to our regular Beloved Customers are extremely practical, they look OK, perform just as well as Perfect Tools, cost a helluvalot less, and most importantly they are waiting on our shelves right now quivering in anticipation of an airplane ride to new masters who will feed them oodles of yummy wood. So which do you think is is better? A perfect prima donna safe queen of a tool that takes years to procure and is too precious to use hard, or a reasonably-priced, hard-working, hand-forged, high-performance, eager but perhaps less than perfect tool you can have right away?
Working With the Imperfect Ura
In any case, please be aware that a chisel with an imperfect ura (nearly all of them have some problems when new) can be perfected over time and will work just fine as-is if you are patient, remain aware of the blades tendencies, and compensate using your eyes and hands accordingly. After all, the chisel only does what you direct it do, so please direct the blade instead of just going along for the ride while drinking adult beverages and smokin wacky-tabaccy in the back seat with Murphy. 〜(シ) 〜
If the plane formed by the ura’s lands is concave, the chisel will tend to undercut the end walls of a mortise, not difficult to avoid with some caution of the sort one must always exercise.
On the other hand (the one with 6 fingers) if the plane is convex, the chisel will tend to scoop away from the end walls of a mortise. All things considered, however, concave is far better than convex.
But whether concave or convex, such irregularities always exist to some degree from time to time in all chisels made by humans and sharpened by hand. It’s the craftsman’s job to manage his tools. Of course, this means we must strive to create and maintain a reasonably flat ura, so let’s consider some practical time-proven solutions that avoid wasting a lot of time, stone and steel, and at the same time don’t prematurely wear out the hollow-ground uratsuki in the process.
Let us begin by observing that the surface area (square millimeters) of the hard steel encompassed within the lands at the ura that we need to eventually make planar can be divided into four areas:
The land immediately adjacent and parallel to the cutting edge (aka “itoura”);
The land where the neck meets the blade, also kind sorta parallel to the cutting edge;
The two skinny side lands, (aka “ashi” meaning “leg”) are more-or-less parallel with the blade’s long axis and located on the right and left sides of the hollow-ground area called the uratsuki;
All four lands are necessary to the chisel’s function, but the one that matters most when sharpening and cutting is the last couple of millimeters at the itoura touching the cutting edge. Please make sure you understand this.
While some people fixate on it, the land near the neck matters least of the four.
The side lands are important bearing surfaces for aligning the chisel in the cut, but they are less important than the cutting edge land, the itoura. If you like your chisels and planes, prefer they remain as easy as possible to sharpen, and intend to use them for a long time, it’s important to understand that working the ura over-agressively on rough stones is the quickest way to wear the side lands down prematurely, thereby making the uratsuki shallower quicker, gradually defeating the subtle genius of the design of Japanese woodworking blades before their time. We want to maintain the ura as deep, long and wide as reasonably possible for as long as reasonably possible.
Allow me to explain this further. As we inevitably grind away on the skinny side lands they will become gradually wider while the hollow-ground uratsuki becomes gradually shallower, with the result that the amount of hard steel we must sharpen/polish will gradually increase, which is inconvenient in so many ways. Sadly, too many people make their chisel’s side lands fat as a sumo wrestler soon after purchasing a chisel in their anal-retentive quest for the totally flat ura. Makes me wanna cry.
The cost-efficient and time-efficient solution is to focus on the important itoura, and make small corrections to the ura’s three other lands over multiple sharpening sessions thereby saving valuable time as well as expensive stones and steel while preserving the ura as long as possible. How to do this? Focus all your attention on the most important area, the itoura, and patiently plan on accomplishing the job over 5~10 sharpening sessions, using the chisel between each sharpening session.
Don’t attempt to correct/polish the ura full-length from cutting edge to neck at first, instead work only the area behind the cutting edge on the stones (which must be flat). To do this, focus finger pressure nearest the cutting edge only. An effective approach is press down on the land nearest the cutting edge while moving the blade on the stones, while the rest of the blade hangs off the stone.
In other words, while pressing down with the fingertip(s) on the face of the blade (the surface opposite the ura with the brand on it) as near as possible to the cutting edge, move the last 5~15mm of the blade onto and off of the stone in a back-and-forth diagonal motion concentrating abrasion where it is needed most. This requires the ability to sense the balance of the blade on the stone, and to apply fingertip pressure where it is needed most. Wow, imagine that.. real hand skills.
If you don’t have these skills now, they are easy to develop with concentration and practice, but it doesn’t happen by accident, and if left unleashed and unmuzzled, your impatient, careless inner badger will try to make a mess of things.
During each subsequent sharpening session, increase the width of the area you work on the stones a tiny bit until the entire ura is flat and can be worked on the stones.
Through this technique and over multiple sharpening sessions, you will notice the ura’s lands will gradually become planar while only the lands nearest the cutting edge increase in width. Honest.
It helps to apply either marking pen ink or machinist’s blue to the blade to confirm whether or not you are applying pressure where it is need most and that abrasion is proceeding as desired.
It is human nature to want to rely on the flatness of the ura’s lands to keep the blade flat on the stone, and therefore we tend to apply pressure at the midpoint of the back so that the pressure on the ura’s land is even at all points of contact. This feels good; It feels stable.
But if you consider the narrow width (and small area) of the hard steel exposed at the side lands compared to the lands at the ito-ura cutting edge and the corners of the blade, you will see why this technique will wear the skinny side lands quickly and prematurely.
Allow me to restate an important point: The goal is to focus hand/finger pressure nearest the cutting with much less pressure focused on the sides lands thereby preserving them, and the depth of the ura, as long as possible. This technique will also save time and expensive steel. It is an advanced skill, but one Beloved Customer should aim to perfect.
Once the ura of your chisel is flat and true, you should not need to true it again unless the blade needs major repairs.
With much use, the itoura will dissapear, and the bevel must be tapped-out (“uradshi”) and the ura re-flattened (“uraoshi”) to restore it. I won’t delve into the subject of “tapping out” the ura of plane blades in this post but a detailed explanation can be found in Part 30of this series.
A detailed example follows.
Evaluate the Ura
The first step in flattening or truing an ura is to evaluate its condition. Don’t start grinding away willy nilly without first checking it and making a plan. If you find you cannot stop yourself, don’t walk but run to the nearest pharmacy and buy a bucket of the medicine discussed in part 19 in this series about maintaining sharpening stones.
There are several ways to check the ura’s condition. A thin straightedge works well in most cases. A thick straightedge may be easier to keep stable on the ura, but it will shut out too much light making observation difficult. Place the straightedge edge-down on top of the full length of the side lands all the way to the cutting edge. Keep the straightedge touching the land; Don’t let it span the hollow-ground uratsuki. Hold the straightedge and blade up to a strong light source and look for light passing between them. This technique is quick and dirty and will suffice in most cases, but does not tell you a lot about twist.
Use a straightedge to check the right and left lands for flatness. It doesn’t do any good to span the hollow-ground urasuki, so don’t bother. These photos are taken from above for clarity, but you want to hold the blade and straightedge together up to a strong light to observe any light showing between them indicating a gap. I am using a small square, but a simple small straightedge is more convenient. This takes a bit of coordination so be careful not to drop a chisel on your toe. I’ve done this once or twice before. Monkey meet football.This is a 30mm Sukemaru atsunomi, a famous brand and an excellent and powerful chisel hand-forged by Mr. Usui from Shirogami No.1 Steel. It’s in pretty good shape, but can benefit from a little truing as can most new chisels and plane blades.
Another method to check the ura for planar is to paint the shiny lands with dark marking pen ink or Dykem liquid, apply a tiny bit of fine sharpening stone mud to a piece of flat glass, like the piece mentioned in Part 17, and rub the blade’s flat or ura over the glass. The high spots will become obvious. If the ura is banana shaped (convex), mark the high spot with your marking pen. More often than not, the ura of chisels will be generally flat, but sometimes the last 2mm or so of the cutting edge will be curved upwards towards the chisel’s face.
I learned two things from my examination of this atsunomi. First, there is a high spot (convex) at the skinny land on one side located approximately 1/2 to 5/8 the blades’ distance from the cutting edge. The land on the other side seems a little low. Hmm, curious. This is a bit unusual, but it happens when a blade warps during heat treat, which Shirogami steels tends to do frequently.
The second problem I observed was that the last 3~4mm of the itoura land at the cutting edge curves downward away from the ura just a tiny bit, enough to cause problems.
I next must formulate a plan to resolve these problems with a minimum of time and effort and without making things worse.
Make a Plan
The temptation to start grinding away immediately will be powerful. But… I must… resist… the… stupidity impulse!!
If it becomes too much, I’ll take a coffee cup or three of the medicine mentioned in the previous post and slather it on my head forcefully. Don’t hold back, for Pete’s sake, rub it in really good now. Some say my excessive use of this medicine is why I am as bald as an egg, but I prefer to believe it is caused by the high-intensity psychic waves radiating from my gigantic brain (ツ). Thank goodness for my aluminum foil skull cap with its artfully protruding copper wires or the radiating light might blind airline pilots passing overhead!
But getting back to practical matters, a useful plan must have goals and objectives. In this case the goal is a perfectly planar ura, but if this goal is difficult to achieve quickly there is an objective you achieve immediately in any case, one that may make it possible to achieve the larger goal over multiple routine sharpening sessions without any special effort.
As I keep harping, to make a chisel or plane work well, you need a sharp, flat bevel and a sharp flat area right at the thin land (itoura) adjacent the cutting edge. This is where the cutting occurs and the area I need to keep sharp, so I will make creating this flat area the first objective in my plan, and then determine the steps to achieve it. I make certain every step in my plan and every stroke I make on the stones gets me closer to this objective, not further away. This means working smart, ruthlessly calming my inner badger (you know, that nearsighted, short-legged snuffling beast that just keeps digging) and repeatedly stomping my stupidity impulse into the ground. Frequent applications of idiot ointment help too.
If the blade is arched (concave), touching at two points, one near the neck of the chisel blade, or head of the plane blade, and at the other at the cutting edge, and not in between, all is well. I recommend you leave a blade like this as-is because after a few sharpening sessions the ura will become flat and twist-free without any special effort, and the blade will become very sharp and be entirely functional (assuming the faces of your stones are flat).
If the blade is wavy (rare) or banana-shaped (convex), your plan needs to take those details into account.
In this example I located the highest point of the bulging area at the ura and marked a line across it with my marking pen. I then measured halfway between this line and the cutting edge and made another line. which I will call the “focus line.” It is here where I need to focus the most pressure when grinding down the ura, NOT the entire length of the blade, despite what my inner badger demands.
The purpose of doing all this prissy planning and layout work is to protect the right and left side lands from being wasted unnecessarily. Newbies and those with poor badger control often insist on working the entire length of the blade on the stones, but this is illogical and ignores three points.
The first point often overlooked or ignored is that the majority of the metal I need to waste is usually located to the right and left of the itoura land nearest the cutting edge, not the full length of the blade, so there is little benefit to grinding the entire ura.
The second point is that the side lands are thin as a blade of grass and will abrade very quickly with almost no effort. Besides, without using large plates and stones, it is very difficult to work the blade’s full length accurately without wearing steps into the side lands anyway.
The third point often ignored is that it makes no sense at all to try to grind down the land nearest the neck since the plane of the ura hinges on this land anyway. Best to leave it alone and focus my efforts where they will make a useful improvement.
Plane blades don’t even have a land near the head, so the futility of working the entire ura on plane blades is even more obvious than for a chisel.
The left photo shows a line drawn at the highest point in the convex ura (bottom arrow), and another line halfway between it and the cutting edge (upper arrow). The second photo shows tape on the blade’s back with the high point line, and the halfway line, or “focus line” at the upper edge of the tape. Use these marks to ensure you have a plan and follow the plan without wasting too much valuable steel at the ura. Notice how narrow the right and left side lands are before we begin working the ura.
Work the Plan
The traditional Japanese tool used to flatten and/or correct ura is a smooth steel lapping plate called a kanaban, meaning “metal plate.” To use it, carborundum powder and water are placed on the plate, and the blade is lapped. This is not a difficult process at all, but there is a tendency for the blade’s perimeter to be ground more than the interior areas as the grit is forced in between the kanaban and the blade’s perimeter. To avoid this tendency, and to speed the process up, I prefer to use diamond plates or diamond stones instead of kanaban.
Whatever plan you developed, and whichever tool you selected for this job, the time has come to work the plan. Do you need more idiot-b-gone medicine? A bigger coffee cup?
First, color the ura’s perimeter lands with a marking pen or Dykem to help you see where the ura is being ground down. Don’t ever guess.
Place the most pressure on the focus line selected above. Move the blade back and forth (not side to side) onto and off of the diamond plate, diamond stone or kanaban with the cutting edge and the focus line always touching the diamond plate or kanaban. Don’t go past the high point for now. Be careful to not grind a notch into the narrow side lands where they meet the edge of the diamond plate or kanaban. Most people make this mistake at first. Please don’t you make it more than once.
Grind the ura down so the line at the highest point and the cutting edge is fairly flat.
Work the blade on and off the edge of the diamond plate using short strokes and without going much past the highest point marked earlier. This works because the right and left side lands are thin and can be abraded in just a few strokes. I have moved my fingers to reveal the lines, but in actuality my fingers will press down hard on the focus line while working the blade.Using a stick to apply more pressure to the blade. I am holding the end of the stick and the chisel’s handle together in my right hand. This is simply illustrating a technique. This chisel did not actually require this sort of aggressive attention.The same stick technique works even better for plane blades and makes it easier to apply pressure right behind the cutting edge. When doing this, however, be sure to work the blade both forward and backward while moving it right and left, on and off the plate’s edge to avoid digging a trench into the narrow side lands.
Remember, the narrow lands at the sides of the hollow-ground urasuki will abrade down quickly. And the rest of the ura can be gradually flattened during subsequent sharpening sessions using regular sharpening stones. It doesn’t need to be made perfect immediately. What matters most is the steel on the itoura land right at the cutting edge.
The high spot on the side land near the top of the photo has been relieved after just a few passes on the #400 diamond plate. The side lands are now both in fair condition, and the land behind the cutting edge (itoura) needs just a little more work.After a few more passes on the diamond plate, the itoura is in good shape. Please observe that the side land at the bottom of the photo is not in full contact, but the opposite side is. This is will not impact the blade’s performance, and will work itself out during future sharpening sessions without special attention.Flattening my stones before using them. Notice I am using two 1,000 grit stones to save time and stones. Don’t neglect flattening your stones, whether you use waterstones, novaculite stones, coticule, or even sandpaper.Working the ura on the flat 1000 grit waterstone. Did I mention it is flat? Notice that I am working on and off the stone, not side to side, to save the right and left lands. Just a few strokes are required. I am now focusing pressure nearest the cutting edge. Some but not all strokes are full length. The goal is simply to remove the deep scratches on the itoura left by the diamond plate. All other deep scratches can be left alone for now and removed during future sharpening sessions a little at a time.The ura after polishing on the flat 1000 grit waterstone. At this point the ura is in good shape. Notice how the land at the photo’s left is wider that elsewhere. This increase in width developed because this location was the high spot on this convex ura. Notice how the land on the right side is not even touching the plane in one area. What you should take away from this photo is the realization that if I had focused my efforts on this high location first and ignored the downward curvature of the land nearest the cutting edge, I would have wasted a lot more time and valuable metal only to shorten the useful life of this excellent chisel. Do you see the benefit of carefully checking the ura’s condition, making a plan with clear goals and objectives, and then working the plan? Did the medicine work? Next, we’ll work on the bevel, make a tiny burr, polish it off by making a few strokes alternating from bevel to ura, and be ready for the finishing stone.Working the bevel on the flat 1,000 grit waterstone. Notice the mud piling up in front of the blade indicating the extreme cutting edge is in contact with the stone. I am applying pressure only on the push stroke to prevent the stone from rocking and developing a “bulging bevel,” A honing jig is not necessary.The bevel after working on the 1,000 grit waterstone. No jigs were used. No “tricks” involving rulers were used. A silly, inefficient “micro-bevel” was neither wanted nor needed. The bevel is perfectly flat. Flattening the ura and polishing both ura and bevel to this level took less than ten minutes. When the purchaser of this blade eventually dulls the edge, he should not need to spend more than 2~3 minutes to sharpen it once his gear is ready, assuming he is able to sharpen freehand.
This flattening process is seldom required except on new blades.
Polish a blade’s ura up to the level of your finest finishing stone once, and don’t touch it with rougher stones again unless it is absolutely necessary, or further gradual flattening is required. This means that in normal sharpening sessions you must remove all the damage at the cutting edge by abrading the bevel with the rougher stones, and only when the bevel is ready for the finish stone, do you work on the flat or ura, alternating from bevel to flat/ura until all defects, burrs, and even visible scratches are polished away.
If you condition the flat (ura) side of the blade correctly, and keep it polished, you should not need to work it on anything but your finish stone until it is time to tap out and grind the ura or back in the case of plane blades. Therefore, the bevel side of the blade is where we spend most of our time and effort.
Now that the ura is in good shape, we will look at sharpening the other side of the wedge, the blade’s bevel, in the next post in the series. In the meantime, keep yer stick on the ice.
YMHOS
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may an elephant caress me with his toes.
Give me six hours to chop down a tree and I will spend the first four sharpening the axe.
Abraham Lincoln
Sharpening stones must be maintained if they are to perform effectively. Abe Lincoln’s quote above is especially relevant to this subject.
There is a lot of hogwash taught as holy gospel on this subject, so in this article your humble servant will suggest some more or less traditional methods that both work well, and are cost-effective. Do with them as you will.
Key Principles
Let’s begin with a few basic but critical principles about sharpening that Beloved Customer should understand and use:
For the majority, but not all, applications, your blades need to meet the following standards:
Flat back/ura: perfection is not necessary but it must be flat enough for you to be able to consistently polish the last few millimeters of steel at the ito-ura (flat adjacent the cutting edge) on your finishing stone;
Flat bevel, for the same reason mentioned above;
Straight cutting edge (except when a curved cutting edge is required).
All Stones get out of tolerance with use. Working a steel blade on a sharpening stone of any kind, whether waterstone, novaculite, coticule or carborundum, wears the stone a little bit with each stroke, creating a dished-out, twisted surface to one degree or another, even if you can’t detect the distortion with Mark-1 eyeball. Therefore, you need to develop the habit of frequently checking the flatness of your stones when in use and truing them when necessary;
Despite what many imagine, a hollowed-out stone cannot reliably maintain a blade with a planar ura, a flat bevel, and a straight cutting edge, but it can damage the blade being sharpened.
The Rule of Seven applies, so reread these three critical points three times, click your heels three times, and ask the gods of handsaws to help you remember them.
Melencolia I by Albrecht Dürer 1514 What are the angel and her little buddy pondering? Sharpening, no doubt.
Pretty simple stuff, right? I apologize if Beloved Customer already knows these things, but you would be surprised how many people know them but still ignore them, and then wonder why their blades won’t behave. Iron Pixies? Nah. Perhaps Mifune Toshiro said it best in Akira Kurosawa’s movie Yojimbo when he quoted the old Japanese proverb: “There’s no medicinal cure for foolishness” (馬鹿に付ける薬はない).
A scene from Akira Kurosawa’s classic movie Yojimbo (1961), the inspiration for the later spaghetti westerns beginning in 1964 and even the more recent TV show The Mandalorian. In this scene, the nameless loner anti-hero is warning off some hired ruffians who have bragged about their judicial tattoos, and the death sentences hanging over their heads, and informed him they aren’t afraid of him or the pain of being cut. The hero responds with the proverb “There’s no medicine for a fool,” then tests their resolve by cutting 3 of them. Ouchy! A hard lesson easily avoided. BTW, if you have tattoos and visit Japan, best to keep them covered since they have an old and indelible association with criminal organizations and judicial branding. On the other hand, if you enjoy being mistaken for a lowlife, violent, thieving piece of scum, by all means show off your ink.
Here’s the scene on YouTube. Please don’t watch it if you are squeamish. Never call the Man With No Name’s bluff.
The Man With No Name (aka Kawabatake Sanjuro played by Mifune Toshiro) pondering the interesting financial opportunities awaiting him in the troubled little post town. His older swordsmith friend (Tono Eijiro) bitterly objects to his plans. The old boy was right.
Although it has only happened once or twice in my recollection (my saintly wife of the jaundiced eye may disagree (ツ)), on those few occasions when I have made a stupid mistake I have been known to ask subordinates to fetch a large bucket of “Idiot Salve” for me from the drugstore. The jury is still out on the effectiveness of this ointment, but I would like some credit for writing this entire article without applying any.
But I digress.
Obviously, if every stroke wears the stone a little, then we must constantly check our stones with a stainless steel straightedge for flatness (length and width) and wind (diagonals) as we use them. It takes 3 seconds. Even if your stones are brand new, you may find distortions. Time spent checking is not wasted if it results in improvement, which it usually does. This is the heart of quality control, and is applicable to everything in life.
Truing Stones
When your check reveals the stone is out of tolerance, you need to flatten/true it. Don’t put it off.
There are many ways to get this job done. Some people advocate using diamond plates to flatten stones. Others insist that sandpaper is best. And then there are the specialty flattening stones. It ain’t rocket surgery. All these methods work, but are unnecessarily costly and time consuming in my humble opinion. The following is the procedure I use. I know it sounds weird. I didn’t invent it but I’ve used it for many decades and highly recommend it. Give it a try, Beloved Customer, before you dismiss it.
Always have two of each of your rougher stones soaked and ready to go when you start sharpening, space and weight permitting. This means 2 – 1,000 grit stones, and 2 – 2,000 grit stones in my case. If you use your tools, owning these extra stones is never wasted money and can improve your efficiency. For instance, beginning the day with two flat 1000 grit stones (the grit your humble servant uses the most) ready to rock n roll means I have 4 flat faces to use before I absolutely must stop work and true them.
If the blade is damaged, for instance chipped or dinged, begin with a rougher stone or diamond plate, whatever you have that will waste metal quickly and easily while keeping the blade’s bevel flat. Don’t waste time frikin around with medium-grit stones when steel must be removed.
If your blade is not damaged, begin the sharpening process with a fresh, flat stone, for instance 1,000 grit if the blade is fairly dull, or 2,000 grit if it’s just partway to dull. Turn the stone end-for-end halfway through the estimated number of required strokes and continue sharpening. This is important to keep your stones true. Yes, you need to keep track of your strokes, at least approximately. This will become second nature with practice.
Occasionally check the stone for dishing and wind using your thin stainless steel straightedge. With practice you will develop a sense of the stone’s condition without the need to use a straightedge, but check each stone frequently while you’re developing your advanced sharpening skills. Stop using the stone when the distortion becomes noticeable.
Switch the distorted stone with your flat stone of the same grit and continue sharpening.
When both stones of the same grit become distorted to the same degree, cross-hatch the faces of both with a carpenter’s pencil, then rub them against each other under running water if possible, or while frequently adding water if running water is not available. Take short strokes and be careful to apply even pressure to the stones. This requires self-control, switching the stones end for end frequently, and making an effort to apply even pressure with your hands, and is more difficult than it sounds until you get used to doing it. The friction and water will wear the high spots down, I promise.
Monitor the pencil marks to track progress.
Check with a straightedge frequently, and stop when both stones are flat, or maybe even a tiny bit convex.
With practice, and if you don’t let your stone’s condition get out of hand, this process should take only a few seconds, but it will ensure you are always working on flat stones.
If you think this technique is slower than using a diamond plate, specialty flattening stone, or sandpaper, you may be overlooking a key point, namely, that using this method one can flatten the faces of two stones at the same time, in the same time period, and with the same hand movements. It may be slower than flattening a single stone with a diamond plate, but it is definitely quicker than using the same diamond plate to true two stones one at a time. Think about it.
It’s also cheaper because diamond plates are costly, and wear out. The specialty flattening stones are not cheap, and they too wear out. Both methods can contaminate stones, in my experience. And sandpaper sheds the most contaminating grit, and is the most expensive method long-term. No-brainer.
Now you have two stones of the same grit on-hand that are flat, free of contamination, and ready to rock-n-roll without wasting time or money on diamond plates, sandpaper, or special flattening tools. These are four fresh, flat surfaces to use before you need to take time away from your paying job. And if you pay attention when sharpening, and take care to use each stone’s entire face, the time between sharpening sessions can be increased while saving significant amounts of cashy money.
Truing Stones Using a Glass Lapping Plate
Finishing stones seldom require flattening, but the same procedure can be used when necessary. A better solution is to the use the float-glass lapping plate described next.
If you need to get a stone extra flat, rub the stone on the ⅜~1/2” (9~12mm) or thicker plate glass mentioned in the previous post. You can often bum scrap pieces of suitable glass from glass stores or contractors. Dumpster diving behind a glazing shop may prove useful if you are careful and don’t cut your arm off. Don’t forget to remove the sharp corners and edges with a carborundum stone or you might end up like the annoying guy in the video linked to above.
To turn the plate glass into a lapping plate, aggressively roughen one side with a carborundum stone or diamond plate, and clean it thoroughly using a scrub brush, soap and running water to remove every trace of glass and stone particles. Then clean your brush and scrub the glass again.
The scratches you just made will turn it into an inexpensive and efficient lapping plate. Trust me. Just wet the glass and rub the stone on it while rinsing frequently. Try to use the entire surface of the plate, not just the center. And be sure to apply uniform pressure to the stone.
If a stone becomes grossly distorted, you can use a rougher stone or diamond plate to true it. Even a concrete sidewalk and garden hose will do the job. However, if you do this, remember that there is no way to avoid contaminating the finer stone with embedded grit from the rougher stone or concrete. This embedded grit must be dealt with before using the stone.
To remove the offending stone particles, scrub the stone’s faces, sides and ends with a rough bristle brush under running water. Finish by polishing the stone’s face with a nagura stone, and rinsing well.
You should also use your nagura stone frequently to dress and true the faces of your finishing stones.
And for Pete’s sake, don’t forget to maintain the edge chamfers on your stones and keep them free of contamination and pixies too.
As with all things, moderation is best. It can be be time-consuming and expensive to keep one’s sharpening stones perfectly flat, but perfect stones are not especially better for general woodworking than a pretty-flat stone.
Beware! For the rabbit-hole of perfect flatness is dark and deep, and sleepless nights and gibbering insanity afflict many who strive to plumb its furthest depths.
Rough Stone vs. Finer Stone
Here is an important factoid you should remember: A stone trued using a rougher stone or diamond plate will be effectively of rougher grit than its designation until its surface is worn smooth again. And it will wear faster too. But if you use identical grit stones (same brand is best) to true each other, the effective grit of each will remain unchanged.
Reread the last paragraph three times, click your heels three times, and do that prayer thing again. Namu Amida Butsu.
Conclusion
It’s important to keep ones’ stones flat and free of wind, and it’s not difficult or time-consuming to accomplish. In this article we looked at inexpensive traditional ways to effectively flatten and maintain our sharpening stones long-term. Give them a try.
Now that our stones are looking good, in the next post in this series of hogwash refutation we will be ready to consider how to use them to flatten and polish the ura of our blades. Y’all come back now y’hear.
YMHOS
I don’t want to hear no more cracks about hogwash. You said to clean the stones, didn’cha!?
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may a family of hogs move into my shorts.
In the previous article in this series your unworthy servant listed some of the tools and accouterments necessary for sharpening Japanese tools using waterstones. In this article we will examine one especially useful stone mentioned previously: the Nagura. I know, it sounds like the name of some evil thing that crawled out of a mountain cave in Angmar in Middle Earth, but if you don’t have this little stone, you should get one.
The Nagura Stone
Nagura stones have been used in Japan for millennia, but they are not unique to Japan. For instance, the Coticule stones of Northern Europe have been used with nagura-equivalent stones since before Roman times. And I would not be surprised if the same tradition existed elsewhere too, they are so useful.
Mikawa Nagura Stone
There are several varieties of Nagura stones mined in Japan, the two most popular being the grey/black Tsushima stone pictured above and the softer white Mikawa stone pictured below. I use a soft white Mikawa Nagura stone for my straight razor.
The black Tsushima variety is cut from sedimentary stone on the ocean floor near Tsushima in Nagasaki Prefecture, located midway between Japan’s Kyushu island and South Korea. I believe it to be the best for general usage so I will discuss this stone in particular.
Like all Japanese natural stones, Tsushima Black Nagura are mined from sedimentary deposits created by airborne volcanic ash being sifted by distance and wind and filtered by waves and tides by the time they reach the ocean floor. But they have not been subjected to the metamorphic weight and heat that makes harder stones, and are relatively soft and permeable. They also tend to crack in the same plane they were laid down in, especially if subjected to wet/dry and/ or freeze/ thaw cycles, so special measures are necessary to protect them.
The Job of the Nagura Stone
The Nagura stone is typically used to perform five tasks.
1. Cleaning Finishing Stones: Finishing stones always become contaminated with pixie dust and grit from rougher stones. A 10,000 grit stone with 1,000 grit particles mixed in is much less than 10,000 grit effective. If you think a stone is contaminated, wash it well with a scrub brush and clean water then work the surface with a clean Nagura stone to loosen and float up the contaminate particles, then wash off the slurry. The stone will be clean.
2. Removing Clogging: Similar to 1 above, the Nagura stone is effective at unclogging dried slurry and metal swarth from the sharpening stone’s surface helping it get back to work sooner.
3. Truing Stone Surfaces: Finishing Stones need to be trued occasionally, usually the corners and edges. Use the Nagura periodically to knock these high spots down. The resulting slurry can be used for your normal sharpening process without it all going to waste. This is wisdom.
4. Reducing Startup Time: Time is money. Waterstones abrade most efficiently when they have a slurry worked up, but it can take time to get decent slurry started on some stones, especially hard ones, and with some blades, especially those with soft jigane. Use the Nagura to quickly bring up this necessary slurry saving time and money. If you focus on the corners and perimeter of your stones, which tend to be high anyway, it will contribute to truing the stone as mentioned in 2 above.
5. Reducing the Average Particle Size in the Slurry: Nagura grit is quite fine. You can add Nagura slurry to a stone (by rubbing the stone to create slurry at corners and edges, BTW) to reduce the average grit size of the slurry making a stone create finer scratches and a better polish on your blades. For instance, adding Nagura slurry to a 8,000 grit stone makes it function more like a 9,000-10,000 grit natural stone without the bulk and weight of an additional full-size stone.
Using the Nagura Stone
Nagura stones are just as useful when sharpening with synthetic sharpening stones as they are with natural stones. In fact, they may be even more useful with synthetic stones since they tend to be harder and synthetic stone slurry containing nagura particles more closely approximates the performance of natural stones.
Nagura stones are easy to use. Simply wet the large stone and rub the small stone on its surface. You may need to add additional drops of clean water while doing this. The goal is to wear down the high spots on the large stone while at the same time producing a slurry mixture from both stones to use when sharpening blades.
The key is to pay attention, use your handy dandy stainless steel ruler to identify the high spots, maybe mark them with a pencil, and use the nagura on those areas first. Don’t be a ninny and rub the nagura all over the sharpening stone’s face willy nilly like you’re washing your pet goat. Make a plan. Work the plan. Develop good habits and speed will follow.
If the large stone is already perfectly flat, and you need to produce a starting slurry, work the ends and corners of the large stone with the nagura in anticipation of those areas becoming high in the near future. That’s a good boy.
Protecting the Tsushima Nagura Stone
Nagura stones are fragile. To avoid water penetration between the sedimentary layers and the cracks that may result, it is wise to use the side of the stone that was in a horizontal plane when it was formed. It is also wisdom to use only one surface of the stone and to coat the stone’s other 5 sides with paint to prevent water infiltration and cracking, and to keep skin oils from penetrating. Traditionally, natural urushi lacquer made from an irritating tree sap has been used for this purpose in Japan, but any high-solids urethane will do the job.
The Nagura stone is a subtle tool. As your sharpening skills improve the value of this tool will become apparent.
In the next article in this depraved series about sex, drugs and goat washing, we will discuss ways to maintain sharpening stones. Some people will be miffed. Others will be thrilled. Goats will be indifferent. What about you?
YMHOS
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may all my sharpening stones sprout clumps of sand.
The finest, softest natural stone your humble servant routinely uses. Black Cashew natural urethane paint (made from cashew nuts) has been applied to the bottom and sides to retard water infiltration and prevent de-lamination in this sedimentary stone. It is a joy to use, and all my blades simply wriggle with joy when it’s their turn for a ride.
Advice is a dangerous gift, even from the wise to the wise, and all courses may run ill.
J.R.R. Tolkien
We receive a lot of inquiries about natural finishing stones, so your humble servant wanted to share some accumulated thoughts and experiences about them with Beloved Customer. Perhaps they will be useful.
To begin with, natural Japanese stones are a lot of fun, and can create a beautiful, cloudy finish on a blade’s bevel. They truly make my heart sing, wild thing.
I believe that blades finished with a natural stone tend to stay sharper a little longer compared to synthetic stones, but can’t prove it. Despite my fondness for them, I want to make it clear that natural stones are not magic, and are not critical to doing good work.
It is interesting to note, however, that while top-quality natural stones are expensive, if judged by the amount of steel they can sharpen, they are actually no more costly than the better synthetic stones. But they can be more of a gamble.
Geologists believe (they weren’t around at the time to witness the event, although they like to pretend they were) that natural sharpening stones typical to Japan were created when particles of volcanic dust fell from the sky, were sorted, and sifted by winds and waves, and settled onto the sea floor eventually becoming sedimentary stone. Sounds likely.
Being natural, they carry the inherent and potentially expensive risk of internal defects, such as weakness between sedimentation layers, cracks, and contamination such as hard particles of sand concealed inside. Even if you find one that seems perfect in every way, the bones never stop rolling because you never know what lurks inside.
This stone is a medium hardness natural finishing stone I regularly use. The stone is epoxied to a base made of Ipe wood. The purpose of this exceptionally hard and rigid base is to: (1) Protect the stone from dings; (2) Reinforce the stone against cracking; (3) Provide a longer, more stable footing in-use; and (4) To span irregularities on the surface being used for sharpening, which often includes the ground in the Japanese tradition. The stone’s sides are coated with a natural urethane called Cashew, a product of the cashew nut tree, to prevent water from soaking into the stone’s sides potentially causing cracks and delamination. The bright orange color is to ensure pesky pixies do not talk the stone into sprouting legs and walking away when outside the workshop. They can be persuasive when talking to stones, donchano.
Your foolish servant erred with his first purchase of a natural stone, one recommended by a hardware store owner in Sendai many years ago. I fear he intentionally foisted a low-quality stone on me that a person more experienced with natural sharpening stones would have rejected. This stone “drags” steel, a phenomenon where the stone deposits hard clumps on the blade that then gouge the stone’s surface and leaves rough spots on the blade. It’s impossible, BTW, to judge a stone’s propensity for this pixieish behavior by eyeball alone.
I learned a bitter and expensive lesson about both natural stones and salesmen that day. I still use that stone for sharpening axes and gardening tools and as a door prop, but the real reason I keep it around is as a reminder of my foolishness.
After that disastrous adventure, I became more careful, pay less attention to what people say or even write, and distrust salemen like thin ice over a rushing river. Consequently, I don’t give a rodent’s ruddy fundament about most people’s opinions on the subject of sharpening stones. Nearly all who claim expertise talk and write about things they only partially understand. Many have a conflict of interest. Still others seek justification of their poor decisions.
Nor I do care about the region or mountain or mine a stone came from, or its designation or color. A word to the wise a stone seller near Kyoto whispered into my shell-like ear some years ago: Even the best mines produce mostly waste.
And because of the impossibility of evaluating stones long-distance, and considering Gildor’s wise words quoted above, I am hesitant to give advice about what stones to buy or where to buy them. But I will tell you what I do when buying a stone:
I examine the stone for cracks and signs of irregularities and impending separation at its sides (not all defects are fatal);
I flip it with my fingertips and listen to the sound it makes. Yes, a good stone sounds different from a bad stone;
I take the stone in my hand, close my eyes, and feel it with my ki 気. Does it feel sound and happy?;
I touch my fingertip to my tongue, wet the stone just a bit, and smell it. Does the moisture soak into the stone quickly, or is the stone too dense? Is the smell clean or muddy?
I touch it to my teeth (an ancient technique for detecting the fineness and consistency of a stone’s abrasive qualities);
I put a plane blade I know well to the stone, take a few strokes, and like a bow on violin strings, I feel the friction and listen to the music made;
I examine the scratches the stone leaves on the blade’s jigane and hagane using a loupe.
None of these critical tests can be conducted long-distance. BTW, if you think any of them are pointless, then I know where you can get a good deal on some swamp land in North Korea with its own lake perfect for a condo development. Well, actually its a settlement pond for a chrome plating factory, but the effluent discharge was recently brought up to 1876 standards so there is no pesky vegetation, or endangered fish or wildlife to deal with, and the price is right!
I have two natural stones I use regularly nowadays. One is of medium hardness suitable for most every straight blade. The other, pictured below, is very soft, and easily damaged, but creates a beautiful foggy finish on the steel.
I love my natural finishing stones, the feel of using them, their smell, the music they make and the pretty finish they produce on my blades. They are part of the romance unique to Japanese blades. I believe the stones I use now and their sisters worn to slivers in past decades were worth every penny I paid for them, but I recognize this is an emotional rather than practical viewpoint, and difficult to defend economically.
Don’t misunderstand: your humble servant is not suggesting you should not try natural sharpening stones, only that you carefully evaluate them in-person beforehand, and buy from a reputable dealer that offers a reliable warranty (please don’t ask for recommendations). And just to prove I am neither troll nor curmudgeon, I will give you the same advice about purchasing natural sharpening stones that a wise old man shared with me a long time ago, advice that has passed Gildor’s test.
Rule 1: Don’t trust your eyes alone when judging a stone’s origin, designation, appearance, or performance (see the five tests listed above): always try a blade on the stone before purchasing it to make sure it works for you and your blade;
Rule 2: Don’t buy a stone from someone you don’t trust and who won’t give you a reliable 30 day warranty to provide time to check the stone carefully for suitability and defects. Remember, the combination of stone and blade is much like a marriage where the softer (but actually granularly harder) stone smooths and polishes the harder blade. If the two don’t work well together, then even lawyers can’t make it right, but a warranty may help reduce the damage;
Rule 3: Don’t whine if the stone disappoints: roll the dice and smile at the spots they show you. Besides, hoes, axes, and hedge shears need sharpening love too.
On the other hand, if you have the stomach for Rule 3 and don’t mind risking your money, then the first two Rules can perhaps be ignored. I grew up in Sin City and know that can be fun too. You pays your money and you takes your chances; Baby needs a new pair of shoes!
Finally, if and when you find the perfect natural sharpening stone, I advise you to protect that lovely thing from damage to ensure it serves you long and reliably. The link below is to an article on this very subject: Protecting Natural Sharpening Stones
YMHOS
Ancient Roman or Norse dice in a pose worthy of gambling.
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