Sharpening Part 27 – The Entire Face

A beautiful face: Oohirayama Lotus stone

If a dog will not come to you after having looked you in the face, you should go home and examine your conscience.

Woodrow Wilson

The subject of how to use the face of your sharpening stone is so basic and seems so unimportant that few give it the attention it warrants. But it is not trivial: it deserves its own post because it can truly make a big difference in the time and money you spend sharpening.

Money Down the Drain

Instead of focusing his attention on the blade alone, a wise man will make a conscious effort to use the entire face of his sharpening stone from edge to edge, end to end, and corner to corner instead of digging an oval swamp in the center of his stone’s face.

This habit will help to keep a stone’s faces flatter over more strokes longer, saving time truing the stone, and extending its life thereby saving money.

Remember that you paid money for the stone, the entire stone, not just the hollowed-out oval area in the center most people create when carelessly sharpening. How much of a stone do most people throw away? Idunno, 20%? If you paid $100 dollars for the stone, that means $20 was turned into mud and washed away without providing any benefit to you at all. And don’t forget that you had to spend time cutting down those high spots to keep the stone’s face flat. That makes it more than a $20 loss if you count your time worth anything, which you should.

Why not use the sides and ends of the stone too?

Developing Good Habits

When developing these intelligent work habits, use a carpenter’s pencil to cross-hatch the stone’s surface to help you keep track of the areas you have not yet touched. Industrial diamonds are made from graphite, it’s true, but pencil lead is still softer than the finest sharpening stone and won’t affect the sharpening process one way or another.

Also, before and while sharpening, frequently use a thin stainless steel ruler to check the stone’s face lengthwise and crosswise at various locations, and of course on the diagonals to monitor wear. Don’t guess, lazy bones, examine. Between ruler and pencil you may discover you have developed less-than-efficient sharpening habits. With some thought you will also figure out how to change those habits so your sharpening efforts will be quicker and more cost-effective.

Before long, you will be able to detect uneven wear and warpage fairly reliably without using either tool as much, so stick with it until you do.

Hang Ten

One conundrum you have probably already discovered is that it is impractical to use the extreme right and left sides and both ends of the stone’s face to sharpen a blade. Or is it? Here is wisdom: Teach yourself how to sharpen with one corner of the blade hanging off the stone part of the time, alternating between right and left corners, of course. Strange as it may seem this technique is effective at not only keeping your sharpening stone flatter, but for keeping the cutting edges of your blades straighter. If this doesn’t make sense to you, think about it real hard. Then give it a try and you will see what I mean.

And since you are taking short strokes anyway, why not work the blade crosswise at the ends of the stone? A lot of expensive stone going to waste there.

I hate to sound like a broken record, but you will find that making short strokes will make it much easier to use the entire face of the stone.

If you feel this post needlessly states the obvious, or is “verbose,” allow me to remind our Gentle Readers once again that the purpose of this blog is not to provide entertainment, sell stuff, troll for clicks or snag subscribers but to help our Beloved Customers develop good work habits through education. Some of them are newbies, and others are old hands, but if I were to write only for the professionals then I would be neglecting the newbies, so if you know this stuff already please congratulate yourself and celebrate your good fortune by buying a new carpenter’s pencil.

Related image

YMHOS

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or profitably “misplace” your information.

Other Posts in the Sharpening Series

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

Sharpening Part 12 – Skewampus Blades, Curved Cutting Edges, and Monkeyshines

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

Sharpening Part 26 – The Taming of the Skew

My relationship to reality has been so utterly skewed for so long that I don’t even notice it any more. It’s just my reality.

Ethan Hawke

The Taming of the Skew

You will have noticed that it is easier to keep a blade stable when sharpening its bevel if you skew it on the stone. There is nothing wrong with skewing the blade so long as you understand the natural consequences of doing so and compensate for them appropriately.

Let’s examine some of those consequences.

First, a skewed blade tends to wear-out, or hollow-out, the center area of the stone quicker. This is inefficient, wasting time and stones, but can be compensated for if you pay attention and work the blade evenly over the stone’s entire face.

Second, people tend to place uneven pressure on a skewed blade, wearing the blade unevenly.

In addition, the leading corner is exposed to more fresher, larger grit particles (which cut more aggressively) than the trailing corner. As a result, the blade’s leading corner tends to be abraded more, causing the blade’s edge to gradually become skewed or rounded in shape over many sharpening sessions. This is definitely bad, and is often mistaken for the work of those devilish iron pixies. But if you are aware this can happen, and pay attention, you can compensate for it. 

Third, and I have no way to confirm this, I am told by the guys with microscopes that diagonal scratches at the extreme cutting edge leave it a tad weaker, causing it to dull just a bit quicker. The way to compensate for this is to keep the blade’s cutting edge perpendicular to the direction of travel during the last few strokes on the finishing stone.

So in summary, habitually skewing a blade while sharpening is fine, but may cost a little efficiency, and may cause your blades and stones to become distorted.

Please read the quotation at the top of this article and consider whether or not your sharpening reality has become skewed without your realizing it. I know mine was for a long time.

These aren’t things you wouldn’t have figured out for yourself eventually, Beloved Customers and Gentle Readers, but now, at least if you pay attention, you’re a few years ahead on the learning curve.

In the worst case, at least ignorance isn’t an excuse anymore.

YMHOS

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Shakespeare’s Shrew, Katherine Minola, played by Elizabeth Taylor in the 1987 movie. In this photograph she’s obviously watching someone skewing a plane or chisel blade while sharpening it. She has the classic “squint eye” down perfectly, as did Clint Eastwood, of course.

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or conveniently and profitably “misplace” your information.

Other Posts in the Sharpening Series

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

Sharpening Part 12 – Skewampus Blades, Curved Cutting Edges, and Monkeyshines

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

Sharpening Part 25 – Short Strokes

Long-term consistency beats short-term intensity.

Bruce Lee
Festina Lente Doors in the Palazzo Vecchio, Florence, Italy

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. The classical references shouldn’t prove too onerous.

If our clever Gentle Readers pay attention to their blade’s movement when sharpening, they 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 rock-n-roll? That’s right, the crapulous bulging bevel rears its ugly head and spits in our eye.

Short strokes, somewhere around 1-½ inch in length, make it 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 and am adding the following clarification to avoid confusion.

A short stroke results in smaller changes in the angles of one’s joints and tendons 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, in the case of short strokes, the angle of joints and tendons at the beginning of a stroke does not change much by the end of the same stroke, making it easier to manage joints and tendons during and between strokes 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.

鑿研ぎ #14_e0248405_1553630.jpg

Please note that this analysis is simply my opinion, and perhaps not a weighty opinion at that because I am not a physician, nor have I conducted physiological studies and dissections upon which a rigorous opinion must be based.

I know that making short strokes feels inefficient, and it is compared to a machine, but you, Gentle Reader aren’t a Cyberdyne Systems product. 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 haste slowly.” It is defined in the dictionary as 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 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

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.

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or conveniently and profitably “misplace” your information.

Other Posts in the Sharpening Series

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

Sharpening Part 12 – Skewampus Blades, Curved Cutting Edges, and Monkeyshines

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

Sharpening Part 24 – Sharpening Direction

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If you do not change direction, you may end up where you are heading.

Lao Tzu

When using the rough stones, and especially when learning basic sharpening skills, it is best to sharpen the bevel in one direction only, lifting the blade off the stone, or at least removing all downward pressure, on the return stroke. The reason for this seemingly inefficient movement is simply that, at least for most people, trying to abrade the blade on both push and pull strokes is extremely likely to cause the blade to rock creating the dreaded bulging bevel.

There are certainly many exceptions to this rule, and we actively encourage you to try to develop the concentration and muscle control required to sharpen in both directions on rough and medium stones, but be aware it may take some years. In the meantime, remember the ancient adage and imperial moto: festina lente, which we chose to translate as “Slow is smooth; Smooth is fast. “

Part of the difficulty of sharpening in both directions is the resulting loss of concentration: the swing of the thing is hard to sense. Perhaps another part of it is due to the difficulty of controlling the complicated and constantly-changing angles of bone and tendon. Both of these natural mental and physical tendencies can be overcome by talented and determined people given time and daily practice, but in the case of everyone I have ever talked with on the subject, it takes many years of focused on-the-job practice, and extreme concentration at first to overcome pre-existing bad habits and avoid developing bad muscle memory.

Which Direction?

At this point you need to make a decision, unless you have already made it inadvertently. That is, to sharpen on either the push stroke (pushing the blade away from you) or the pull stroke (pulling the blade towards you). Most people choose the push stroke, as do I, but in reality the pull stroke is actually a little more efficient because the pressure tends to focus closer to the bevel’s front instead of back, and rocking is reduced. Whichever direction you choose, use it consistently.

However, and this is critically important, when it comes to the final finishing stone, work the blade back and forth in both directions. The finishing stone is not abrasive enough to change the bevel’s shape, and since you need to polish the last few microns width of blade’s cutting edge, a very tiny amount of unintentional rocking is actually helpful, as mentioned in a previous post.

Training Techniques

If you decide you want to develop the ability to sharpen on both push and pull strokes, I can share some helpful guidance that was given to me many years ago by a sword polisher.

The first step in training yourself is to begin by lifting the blade on the return stroke (either push or pull depending on your preferred direction). All the things mentioned above apply. Becoming proficient with this technique is foundational. Strive to project your senses into the blade traveling over the stone, indeed right down to the last few microns of the cutting edge.

When you are able to create a sharp edge while maintaining a flat bevel consistently and without much concentration using this “one-way” technique, then move on to the second step, which is to keep the blade in contact with the stone on the return stroke, but relieve all downward pressure. Begin slowly with full concentration and and seek for smooth motion. It’s at the transition from one direction to the other where those nasty iron pixies cast their spells of confusion.

And finally, when you have mastered the “light-touch” technique, try applying downward pressure in both directions, beginning slowly at first and with full concentration striving for smooth motion.

Remember, don’t grip the blade like a thrashing snapping turtle, but hold it lightly in your hands like a small bird: too tightly and it will be crushed; too loosely and it will fly away. Don’t lock your wrists or elbows, but actively and consciously rotate them to keep the blade’s bevel always perfectly flat on the stone (your stone is flat right, right?). And don’t forget to use your small, thin stainless steel straightedge and brass bevel gauge to frequently check the bevel for flatness and proper angle.

And as always, brutally crush bad habits, and don’t allow new bad ones to take root.

Sadly, this is a skill that, once learned, tends to deteriorate with time unless practiced frequently. As with cherry blossoms, muscles, tendons and eyes are neither static nor eternal. Setsunai, desu ne.

YMHOS

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or conveniently and profitably “misplace” your information.

Other Posts in the Sharpening Series

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

Sharpening Part 12 – Skewampus Blades, Curved Cutting Edges, and Monkeyshines

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

Sharpening Part 23 – Stance & Grip

When the show starts, I am in my SpongeBob stance, and I walk like SpongeBob, and the first step that I take, I am SpongeBob.

Ethan Slater
Ok boiz and gurlz, ready to sharpen?!

Stances

There are several practical stances for sharpening, including standing, sitting on a bench or in a chair, squatting, kneeling on the floor, or sitting on the floor. With practice, all these stances can be made to work well.

When starting out, however, I think most people benefit from using a standing position with the stones placed on a workbench or table, or on a board spanning a sink. 

Whichever stance you choose, locate and be conscious of your center of gravity, (usually just below your belly button), and try to keep it at the same elevation while moving the blade forward and back. 

Flex your knee joints, and loosen your elbow joints and wrists. Locking up your wrists and elbows will make it impossible to avoid rocking the blade. This is important. Actively concentrate on allowing the wrist to rotate in a manner to keep the blade’s bevel flat on the stone’s face.

In the case of a normal resharpening job, instead of a major repair, remember the goal: to abrade and polish the last few microns of steel at the extreme cutting edge, using the flat bevel as an alignment jig, exactly as craftsmen have been doing for thousands of years.

Don’t let yourself get lost in the forest of trees and focus just on abrading and polishing the entire bevel. Focus the majority of pressure on the extreme cutting edge, and less on the rear of the bevel, but without lifting the rear of the bevel off the stone. In the case of Japanese blades, the rear of the bevel is all soft jigane iron and will take care of itself. Yes, it is a balancing act. Yes, it takes focus. Yes, you will make mistakes, overbalance, gouge the stone and mess up the cutting edge a time or two. Everyone since the day the first caveman tried to grind his stone axe on another stone has made that mistake, so don’t worry about it. You fell off your bicycle the first few tries, scraped your knees and elbows, survived, and now ride like the wind! Yiiiiiihah!

Get a Grip

The way you hold your plane or chisel blade during sharpening will greatly influence the quality of the end product and the stress placed on your hands during the process, so it is worth paying attention to.

There are as many was to hold a plane or chisel blade when sharpening as Baskin Robbins has ice cream flavors. And like ice cream, none are right or wrong, except Burgundy Cherry, which of course is superior to all others (ツ)。 In the interest of brevity, we will only look at three grip methods. If you are not using them now, I suggest you give each a try over a couple of sharpening sessions to see if they are an improvement or not. Feel free to adapt these or develop your own from scratch once you understand the key points.

The Gorilla Grip

First, let’s examine what I call the “Gorilla Grip.” With the plane blade resting ura facing up, the blade’s long axis pointing at 11:00, and the cutting edge furthest away from you, grip the blade’s sides with your right-hand’s thumb on the left side, ring finger and pinkie on the right, the tip of the middle finger resting on the right corner directly behind the cutting edge, and index finger extended alongside the middle finger. Then lift the blade and roll your ring and pinkie under it.

Rest the tip of the ring finger of your left hand on the left corner directly behind the cutting edge, with your middle finger and index fingers extended and their tips resting adjacent.

Extend your left palm over your right thumb’s last joint, and wrap your left thumb under the blade. You are now ready to rock-n-roll, without the rocking and rolling motion

The advantage to this grip is that it is very strong, ergo “ gorilla.” The downside is the blade tends to end up skewed on the stone because the right wrist must be twisted to keep the blade straight. Also, because the wrist joints are at very different angles with respect to the blade, and it is easy to apply a lot of force, extra care is necessary to keep the wrists firm but loose and rotating in harmony.

Notice how thumbs are poised to fit under the blade’s head
Four fingers pressing down on the blade’s ura as close to the cutting edge as reasonably possible.
Finger position on a chisel. The left hand thumb passes under the blade’s neck supporting it vertically, while the pad presses against the neck’s right side. The right hand thumb passes over the top of the neck, restraining the tool vertically, and presses against the neck’s left side firmly securing the neck between both thumbs. More fingers can press down on the ura in the case of wider blades. Conversely, only one finger can press on narrow blades.

The Three-finger Grip

The other grip is one I call “three-finger,”(指三本) after the most proper way of bowing in Japan when seated directly on the floor (preferably tatami mat) in the “seiza” posture with legs folded underneath the body, both hands touching side by side with the pads of three fingers of each hand extended and touching the floor in front of the knees, and the thumbs and pinkies tucked out of sight. Very proper, and elegant especially for ladies.

In the case of the three-fingers grip, the blade is oriented directly in front of and on the body’s centerline with cutting edge furthest away. The hands hold the blade in a more symmetrical fashion than the gorilla grip, with the middle and index fingers pressing down on the blade’s corners closest the cutting edge (depending on the space available), with the thumbs curled under the blade’s head (end opposite the cutting edge), and either the ring fingers or pinkies touching the blade’s sides to assist in lifting it.

The advantages to this grip are less tendency to skew the blade, looser wrists, and better control of bevel angle. The disadvantage is slightly less power because it is harder to get the shoulders over the blade. This is the burgundy cherry version, in your humble servant’s opinion.

The Three-finger Monkey Grip

A hybrid of these two methods is one I call the “three-fingered monkey.” Place the right-hand thumb alongside the blade’s left side, instead of under the head forming a combination of the gorilla grip and three-finger grip. This method provides a little more power than the three-finger grip, and less skew than the gorilla grip.

Is one of these grips best? It’s like riding a bike: None are wrong, but some work better than others.

 In all three of these grips, most of the pressure will tend to focus at the blade’s corners which can create uneven wear on the ura. While this may be unavoidable, especially in the case of narrow blades, try to focus the majority of pressure on the centerline of the cutting edge. It seems insignificant, but if left uncorrected, the resulting unbalanced pressure will cause the blade to wear quicker at the corners and become curved. Yes the blade is iron and steel and does not flex much, but it is a verifiable fact that the points where your fingers apply pressure will be abraded quicker.

There is a saying in Japan which is quite appropriate when talking about sharpening that says “Dripping water wears away stone.” In this case, just a little differential pressure from your fingertips will shape the blade over many weeks and many passes over the stone, wearing away both stone and steel in useful ways or not. It is worth being aware of this potential and paying attention.

Chisel Grip

The grip I use on chisels is very similar to the grip for planes, and varies with width. 

The long handle makes chisels tail heavy and a bit more difficult to manage so it is often useful to select a grip style that is absolutely stable using just a single hand.

Most solutions involve holding the chisel in the palm secured by middle finger, ring finger, and pinkie, with the index finger extended and centered right behind the cutting edge.

The index and middle fingers of the other hand can also be pressed near the edge and the thumb wrapped underneath the handle.

Polishing the Ura

Polishing a 70mm plane blade’s ura.

When polishing the ura of a blade, be it plane or chisel, make sure the stone is flat. If it isn’t, you will regret it later without realizing why.

Let’s look at a plane blade first. Notice in the photo above how my right hand is curled under the blade’s head supporting it while my thumb presses down on the bevel close to the cutting edge, a grip that makes it easy to apply a lot of pressure precisely while maintaining control of the blade.

Two fingertips of my left hand are pressing down on the bevel for a total of three pressure points. The thumb can press down as light or hard as you feel is necessary, but it typically applies the highest amount of pressure. It’s important the left hand fingertips apply equal downward pressure to avoid creating uneven wear (unless one corner of the blade specifically needs more pressure applied).

Try to remove nearly all the weight of the blade’s head from the stone so that all but a tiny amount of applied pressure is focused on the “itoura” cutting land at the blade’s extreme cutting edge. No good can come of wearing a trench into the ura’s side lands.

Move the blade in two directions at the same time: Mostly to and fro in line with the cutting edge; but also on and off the stone’s edge perpendicular to the cutting edge. This will help avoid wearing a trench in the side lands and produce a stronger cutting edge (IMO).

Keep the stone flat and reverse it frequently to ensure even wear and less wasted stone.

Concentrate your senses and develop hand-soul coordination : You are a leaf on the wind; Watch how you soar (Hoban “Wash” Washburne in Serenity). I hope you have better luck than Wash did…

In the case of chisels, I hold the handle in the palm of my right hand and place thumb and forefinger on opposite sides of the neck/shoulders pinching it between them. I place the tips of the fingers of my left hand on the bevel, and move right and left hand together. And as in the case of plane blades, I move the blade both forward and backwards and left to right at the same time.

Give it a try. What do you have to loose?

In the next post in this series on sharpening, we will look at which direction to sharpen in. Few give this matter any thought, but most should.

YMHOS

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or conveniently and profitably “misplace” your information.

Previous Posts in the Sharpening Series

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

Sharpening Part 12 – Skewampus Blades, Curved Cutting Edges, and Monkeyshines

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

Sharpening Part 22 – The Double-Bevel Blues

The fool doth think he is wise, but the wise man knows himself to be a fool.

William Shakespeare, As You Like It
It is well with me only when I have a chisel in my hand – Michelangelo Buonarroti 1475-1564

In the previous post in this series on 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 bulging bevel. In this post, I would like to touch on a subject that will make thoughtful people think and befuddled folks lucid: 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 my opinion:

  1. 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. 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 there will be a price to pay later over many sharpening sessions to restore the proper bevel, so it is only a temporary, not a long-term solution;
  2. 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.
  3. 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 cuts 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.

Image result for lie-nielsen honing jig photo

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 use 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 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 workable, 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 an 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 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 demonic 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.

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 unintentional 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 mouth, or even slightly dampen the wood with a planing fluid such as water, whiskey, or unicorn wee wee. All these methods can help.

On the subject of planing fluid, water works well but dries slowly and can have problematic secondary effects. And 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. First, whiskey has a good water/alcohol ratio that wets the wood about the right amount of time and then evaporates cleanly. Too wet and it penetrates too deeply. Too dry and it evaporates too quickly. Isopropyl alcohol works fine too but it is considered a pharmaceutical in Japan and so is very expensive. As with other alcohol products not intended for internal consumption, it contains poisons added at the demand of greedy governments for the sole purpose of maximizing tax revenues. I don’t need those poisons touching my tools or my skin. Whiskey doesn’t contain poisons (other than alcohol, of course), it’s cheaper and smells better.

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 nosehair 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 are careless, or use it too often, the nano-bevel will become a microbevel, 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 will fall out and your dog will barf whenever it sees you! Or is it your dog’s hair will fall out and you will barf? I forget.

Now where did I set down that jar of planing fluid….?

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 train yourself 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 Dude, I’m done sharpening using my most excellent honing jig for now and am off to the beach on my chick magnet! Don’t wait up, Mom.

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

Sharpening Part 12 – Skewampus Blades, Curved Cutting Edges, and Monkeyshines

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or profitably “misplace” your information.

Sharpening Part 20 – Flattening and Polishing the Ura

A mind needs books as a sword needs a whetstone, if it is to keep its edge.

George R.R. Martin

Now that we are geared-up and our sharpening stones are flat, let’s make our blade sharp. The first step in sharpening a new blade is truing the ura. So let’s get to it.

General

All standard chisel blades and plane blades, whether Japanese or Western, need to have a planar flat or ura that it will be in contact with the sharpening stones its full width, and ideally, full length. Perfection is not necessary, however, so don’t let yourself get obsessive. If the ura is arched (concave), for instance, so it is in contact with a flat sharpening stone near the neck of a chisel, or head of a plane blade, and the cutting edge, that may be workable, but it must be in complete contact right behind the cutting edge. I cannot stress this importance of this point too strongly.

Once the ura of your chisel is flat and true, you should not need to true it again unless the blade needs major repairs. Japanese plane blades, on the other hand, are a little more complicated because repeated sharpenings tend to gradually wear out the land right in front of the cutting edge, called the “ito ura,” and the bevel must be tapped-out to compensate, and the ura re-flattened. I won’t delve into the subject of “tapping out” the ura of plane blades in this post but will save it for future discussions about Japanese planes.

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 narrow straightedge works well in most cases. Place the edge on top of the full length of the shiny land at one side of the ura all the way to the cutting edge. Keep the straightedge touching the land; Don’t let it span the hollow- ground urasuki. 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 that will indicate 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-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 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 the last 6mm or so of the cutting edge will be curved upwards towards the chisel’s face.

I learned two things from my examination of this Sukemaru brand atsunomi. First, there is a high spot (convex) at the skinny land on one side located approximately 1/2 to 5/8 the blades’s 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 land right behind the cutting edge curves downward away from the ura just a tiny bit, enough to cause problems.

I next need 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. If it becomes too much, take a coffee cup or three of the medicine mentioned above and slather it on your 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 light radiating from my gigantic brain (ツ). Thank goodness for my aluminum foil skull cap with its protruding copper wires!

Any plan needs 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 should plan to 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 flat area right at 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. Make certain every step in your plan and every stroke on the stones gets you closer to this objective, not further away. This means working smart.

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.

If the blade is wavy (rare) or banana-shaped (convex), your plan needs to take those details into account.

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. This area we 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.

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 try to work the entire length of the blade, but this is illogical and ignores three points. The first point is that the majority of the metal I need to waste is usually located to the right and left of the 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 notches in the side lands anyway. The third point is it makes no sense to try to grind down the land nearest the neck since the plane of the ura hinges on this land. Best to leave it alone and focus my efforts where they will make a difference.

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.

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 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 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 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.

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 in 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 land right at the cutting edge.

The high spot on the land near the top of the photo has been relieved after a few passes on the #400 diamond plate. The side lands are 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 ura is in good shape. Note the land at the photo’s bottom 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. Some but not all strokes are full length. The goal is simply to remove the deep scratches left by the diamond plate.
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 left 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 this blade once his gear is ready, assuming he is able to sharpen freehand.

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.

YMHOS

Links to Other Posts in the “Sharpening” Series

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

Sharpening Part 12 – Skewampus Blades, Curved Cutting Edges, and Monkeyshines

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or profitably “misplace” your information.

Sharpening Part 17 – Gear

Do what you can, with what you have, where you are.

Theodore Roosevelt

Sharpening can be a stuff-intensive process, so I want to reduce the number of accoutrement to the barest minimum especially since portability is always a factor in my case. The following is a list of some gear, besides sharpening stones, that I am confident will prove useful whether in your workshop or the jobsite.

I will first list the gear needed for general sharpening either in the workshop or the field. At the end of this article that I have listed a minimal set of gear for use specifically in the field where space and weight might make it inconvenient to carry the heavier/bulkier general set of sharpening gear.

General Set of Sharpening Gear

The following is a list of tools and equipment I think are indispensable for sharpening Japanese woodworking tools in general and in many, but not all, circumstances. I have not included some tools that may be necessary for doing “uradashi,” i.e. “tapping out” the hollow-ground urasuki of Japanese plane blades. So here we go.

  1. Stone Base or Holder: A wooden base with a wedge to secure stones is the old standby, but repeated wetting and drying and the resulting expansion and contraction may compromise a wooden base over time. For my synthetic stones I have come to prefer the commercial bases with twin metal rods and rubber feet. They are unromantic, but are durable, stable, non-slip, grip the stone tightly without breaking it, and work well anywhere. If you decide to make and use a wooden base, I highly recommend Ipe wood because it is stable, unaffected by water, won’t rot, and bugs hate it.
Washing powder storage square plastic buckets in 2L 5L 8L 10L 15L 18L 20L

2. Soaking Bucket for stones: A medium size plastic or steel mop bucket (not the heavy industrial unit with rollers) is best for soaking stones because they are durable, and their more or less rectangular shape is superior to round buckets for leaning stones on end against the inside walls. You don’t want to stack the stones on top of each other if you can avoid it. Any durable bucket that doesn’t leak will work, but a tightly-fitting lid is a big advantage. You will need to soak all but your diamond plate and finishing stones in this bucket before use. 

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I soak my synthetic stones 365 days a year. I close the lid to prevent evaporation and keep out mosquitoes, journalists and tax collectors, and add either washing soda, borax or a few drops of Simple Green ProD5 concentrate to the water to prevent bugs and algae from growing when I won’t be using the stones for a while. Simple Green is a better bug/algae killer, but Borax has the advantage of making the water slightly alkali which helps prevent rust in my blades during sharpening.

Some stones use a magnesium-based binder that can dissolve and weaken them if left soaking for long periods of time. Please refer to the manufacturer’s instructions.

3. Glass Plate: 9mm~12mm thick float glass. This is used to true the faces of waterstones when they become distorted through use. The piece I use is 60mm x 30mm x 10mm. This plate can be used for many other purposes including checking the fettle of your plane’s soles. I leave this in my workshop. We will discuss how to use this in future posts in this series, God willing and the creek don’t rise.

4. Working Surface: If working outside, a Japanese craftsman will place his stone holder directly on the ground or concrete slab. A craftsman that works inside a shop will often have a wooden or plastic box with a board spanning the narrowest dimension forming a bridge. The stone rests on this bridge, often with a wet towel between board and stone to prevent slipping. This box, called a pond, catches water and mud dripping from the stones. The ideal situation is a board spanning a sink with a faucet of running water. When away from the workshop, I prefer to place a piece of fiberglass-reinforced rubber roofing membrane on a truck’s tailgate or stack of boards or gypboard at a jobsite. I can roll-up this lightweight, tough, and absolutely waterproof mat and stuff it into my toolbox for easy transport. In my workshop, I use a large plastic cutting mat on my workbench, but any waterproof non-slip surface will work. No need to get fancy. My stones and sharpening gear are stored under my workbench close at hand. 

5. Water Source: While sharpening, you will frequently need water to wet your stones and rinse blades. If you work at a sink, use the faucet. If you work outside, a garden hose works great. Some people, mostly knife sharpeners who seldom use stones finer than medium grit, will scoop water from their pond or bucket to wet their stones. However, since stone slurry drips into the pond, or washes off the surface of stones soaked in the bucket, this water will always contaminate stones with the grit from rougher stones, making it difficult to remove all the scratches left by the previous stone. To avoid this contamination, always use clean water for wetting and rinsing. 

Some people prefer a spray bottle to add water, but spray bottles wet things I prefer to keep dry, so a better choice, in my opinion, is a plastic bottle such as a dishwashing soap bottle or a plastic lab wash bottle with a bent tube coming out the top. Almost any plastic squeeze bottle will work.

Tap water contains chlorine in all but backward countries, and chlorine accumulates and accelerates rust, so I use distilled water in my wash bottle, and add washing soda or borax to adjust the water’s PH, a technique I learned from sword sharpeners. 

Some people add just a bit of liquid lye to their water to adjust the PH. This chemical can be purchased from industrial cleaning supply companies. Too much will damage your skin, so be careful. Also good for keeping Iron Pixies in the shadows.

6. Sharpening Station and/or Sharpening Pond: I don’t use a sharpening pond, and don’t believe them to be essential, but several practical options are illustrated below.

余暇のある時や休日だけに出現するものであるにせよ、専用の研ぎ場があるというのは工作をするものにとって幸せなことです。自分なりに工夫を重ねながら研究を深めてゆくのは、何よりも楽しみを感じさせてくれるでしょう。
A bridge placed over a sink forms the ideal sharpening station. Professional workshops frequently use this classic arrangement. Flush the drain well. You may need to remove the sinks’s P trap and clean sharpening stone mud out of it every couple of years.
Plastic boxes placed inside a wooden box make a portable sharpening pond and stone storage box. There are dozens of variations on this theme possible.
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Perhaps the best solution in my experience (short of a dedicated sink) is a plastic box to catch water, with another plastic box nested inside containing sharpening accoutrements such as a wash bottle, brush, abrasive powders, an oiler, and nagura stone. This equipment, along with the sharpening stones, 2 bases and stainless steel straightedge pictured, can be stored inside the box and the lid closed for ease of transport and to keep out pixie dust. This is an inexpensive and extremely practical solution, but be sure to use a high-quality box made of high-impact plastic.
Another plastic box used as a sharpening pond with a simpler bridge.
Image result for straightedge

7. Stainless steel straightedge: Use this to check stones for flatness and wind, and cutting edges for straightness. Don’t use a plain steel one unless you want to give the iron pixies skulking under your workbench great joy. The thinner the better. The thick blades used in combo squares are difficult to use in less than ideal light

8. Wiping materials: You will need something to clean and dry your blades during sharpening sessions. Rags work well for wiping and drying blades, and can be washed and reused, but be careful to avoid cross-contamination. Paper towels are most effective and convenient in my experience, but they cost money and make garbage. Decisions decisions.

The classic Japanese “Baby Turtle” brush with palm-fibre bristles.

9. Scrub brush: A clean stone is a happy stone, as are bases, buckets and glass plates, all of which have grooves and scratches and holes where grit can hide. Scrub brushes are great for digging out this contaminating grit. Palm fiber brushes are ideal because the bristles are finer and grit does not get embedded into the bristles as much as plastic brushes.

Lie-Nielson Honing Guide. An excellent if expensive tool.

10. Honing Guide: This tool is optional. I hesitate to recommend these jigs because they can easily become a crutch preventing you from becoming proficient at freehand sharpening. However, jigs make it much easier and quicker to shape blades to the desired angle on rough stones, especially when correcting a double-bevel or bulging bevel to a more useful single, flat bevel. Eclipse-style honing guides work well. The die-cast versions are inexpensive. Lie-Nielson makes a terribly expensive version machined from stainless steel that I am fond of. Jigs won’t work for all blades, but it is worth having one.

tzushimanagura8_4
A Tsushima Nagura Stone

11. Nagura Stone: More details will be included in next post in this series.

Minimal Set of Sharpening Gear

Sometimes, especially when working at remote jobsites, weight and/or space may impose physical limits on the tools we can carry with us. The following is a list of the minimal set of sharpening tools I bring in these situations.

1. Stone Base: At the jobsite the stability this tool provides becomes more critical than ever, but if an ultra-light set of tools is needed, then it can be eliminated by placing the stone directly on the rubber sheet I use as a portable working surface.

2. Soaking Container: There are many potential solutions for soaking stones in a minimalist or ultra-light situation. I will describe just a few here. If I need to able to move wet waterstones to and from the jobsite during the workday, but a bucket full of water is not convenient to haul around without a truck. If clean water is available at the jobsite (water coming from newly-installed pre-flush plumbing may not be clean, BTW, and immediately post-flush it may contain lots of chlorine used to sterilize the pipes and fittings), then the minimalist solution I employ is to use a dry plastic bucket to carry tools, including sharpening gear, to and from the jobsite. I then add water before beginning the work day. Depending on the other tools I will need during the workday, this is often a good choice. Another option is to scrounge a joint compound bucket or paint bucket and leave it at the jobsite. But unless I have a gang box or other trustworthy tool lockup available at the jobsite, I still may need to transport at least one wet sharpening stone to and from the jobsite each day. The ultra-light solution I sometimes employ is to carry my waterstone(s) in a durable plastic container with a watertight lid, such as the thinner (6cm) rectangular containers by Tupperware. Water can be added at the jobsite to keep the stone(s) soaked and ready to rock-n-roll. And with the lid closed, dirt and dust can’t get in. An even lighter option is a heavy plastic bag. I place the stone(s) in the bag and carry it in my tool bag. At the jobsite, I can add water and close the bag with a thick rubber band to soak the stone(s). But be forewarned that these bags will not protect the stones, and the stones will make holes in the bag at the worst possible time.

3. Working Surface: I use the fiberglass-reinforced rubbber roofing membrane described in item 4 above. This is invaluable for many applications.

4. Water Source: Clean water is necessary even in the field to add to the stones and to wash mud off tools. To save space, I use a small plastic squeeze bottle with a tightly closing lid that originally contained ketchup. If clean water is available at the jobsite, I carry it in my toolbag empty.

5. Stainless Steel Straightedge: See Item 7 above. I use a thin, flexible, lightweight one in the field.

6. Wiping Materials: A clean face towel and a some folded paper towels work well.

7. Scrub Brush: I always bring my “Baby Turtle” scrub brush. It’s lighter in weight than a plastic brush and comes in handy for tasks beyond sharpening too.

8. Nagura Stone: Just in case I need to get an extra-fine finish.

The selection of stones I use at the jobsite will depend on the work planned for that particular day, but the minimal set is a 400 grit diamond plate, a 1,000 grit synthetic waterstone, and a 6,000 or 8,000 grit synthetic finishing stone. If I anticipate a lot of sharpening, and if weight is not critical, I will bring two 1,000 grit stones to provide 4 flat sharpening surfaces thereby reducing the need to spend time flattening stones at work. I can also use them to flatten each other. If I need to do some fine finish planing, such as when doing door modifications/installations, I will bring a 10,000 grit synthetic waterstone. And of course I always carry a Tsushima Nagura stone.

In the next post in this romantic series of adventures in sharpening will focus on the important Nagura stone. Stay tuned for muscled thews and busted bodices!

YMHOS

Links to Other Posts in the “Sharpening” Series

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

Sharpening Part 12 – Skewampus Blades, Curved Cutting Edges, and Monkeyshines

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

IfIf you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or profitably “misplace” your information.

Sharpening Part 15 – The Most Important Stone

Orders are nobody can see the Great Oz! Not nobody, not nohow! 

Gatekeeper, Emerald City

Many people high-center on the question: “What is the best way to sharpen my tools?”

I was hesitant to publish this series of posts about sharpening because, beginning with this post, I must answer this question by writing about tools and techniques that contradict many people’s sharpening religion. Some of those people will doubtless become emotional. As Benny Franklin once famously said: Ça ira, ça ira.

The objective of this post is to help our Beloved Customers properly maintain, sharpen and use the blades they purchase from us. Nothing else.

This post will not be a sharpening tutorial; that will be a future post.

We will examine the process of sharpening woodworking tools using mostly waterstones. We will touch on the motivations, goals and priorities related to sharpening you should consider, the minimum set of sharpening stones I recommend, and my suggestion for the most important stone in your arsenal, one you must be proficient in using.

Motivations

The Great and Powerful Oz has spoken!

You might have noticed from my previous posts that I like to understand motivations. Am I cynical? Perhaps, but where there are smoke and lights presented and money to be made, there is almost always someone behind the curtains spinning dials and pumping pedals. Oooh, pretty lights!

Anyone who does anything has a motive for doing it, and knowing that motive can help us evaluate the validity, and sometimes even the honesty, of what they do, say and write on a particular subject. How can we best ascertain the motivations of those advocating various sharpening methods and related accoutrements? Here are some simple questions you might want to ask: Are the promotions or promoters touting sharpening stones or other stuff they might profit from? Are they selling books on sharpening? Do they teach classes on sharpening? Do they have “sponsors” or “patrons” that supply them, at no cost or with large discounts, stones, diamond paste, sandpaper, sharpening machinery, and/or honing contraptions in exchange for promoting those goods? Are they “influencers” (yes, that’s a real vocation in the YouTube World) who are compensated for clicks? Do they publish reviews on products they receive for free? You see the pattern.

Regardless of their business model or motivations, many people give good advice. But some are shills, while some others are pretenders, and their advice will be colored accordingly. Caveat emptor, baby.

And then there is the most obvious motivation. After all, it doesn’t cost even $20 to make a Mechaultrasuperfine Ninja-purple Gold-dust-infused Musashi Walk-on-Waterstone that retails for $650. And have you calculated the long-term equivalent cost of diamond paste and abrasive films? Somebody’s making serious cash.

Just once I’d like to cross the road without having my motives questioned…

Whatever stones you select, I urge you to find a good balance of performance vs cost vs time vs sustainability, with sustainability referring to both the amount of landfill-stuffing the selected process creates as well as its long-term effect for good or ill on your blades. This 4-variable calculus depends not only on the characteristics of the stones and blades you use, but on your sharpening skills too, so it may take years to find the inflection points if you take a scientific approach. The quadratic formula does not yield useful results, sorry to say.

At one time or another I have tried and tested many popular sharpening “systems” including those that rely on jigs, machinery, sandpaper, plastic films, stick, liquid, paste, and powdered abrasives, buffers, strops and even superflat ceramic plates. I enjoy learning new things. They all get the job done, and all have serious merits, but to reduce the time and brain damage involved in this calculus, a wise man will learn from professionals, people who have been down the road before and actually use tools to feed their families, and who have no conflict of interest, be it stones, books, or clicks. That’s what I finally did, and I think it worked out well. But I need to issue a disclaimer before we go further.

Disclaimer

Here it is in red letters.

I say what I believe and believe what I say, even if it offends the “gurus” of sharpening. I buy their books and DVDs, watch their YouTube videos, and try the sharpening techniques and even the “tricks” they recommend, so I like to think I am not a “frog in a well,” as the Japanese saying goes. If I don’t know something, I will say so. I am not a child to be offended if you disagree with me, but I ask you to not become orcish.

Please note that we do not now and have never received goods, discounts, or financial compensation of any kind from anyone in exchange for modifying our opinion about sharpening tools and techniques.

I have personally taught many people how to sharpen tools over the years, but have never received a red cent for my time and haven’t used those training sessions as an excuse to sell stuff.

I have never done a product review.

I have never written a book or magazine article or even a blog post with advertiser support.

Please note that the document you are currently reading cost you nothing, was written and paid for by C&S Tools alone, and that there are no banners, commercials, or outside links on any of the pages in this blog. No SEO strategy at all. If Evil Google brought you here, it was not at our bidding.

We want to help our Beloved Customers, mostly professional woodworkers who already possess a certain level of skill, to level-up those skills. C&S Tools has no commercial incentive to mislead, and will not do so. But we do have a profit motive.

Remember, we have a 100% guarantee on the materials and workmanship of the tools we sell, so our sole financial motivation, and the very reason for this blog, is to help our Beloved Customers understand the tools we sell, and to become proficient in sharpening, maintaining, and using them so they won’t mistake a lack of skill and/or experience on their part as a problem with the tool. All most professionals really need is a little guidance. We want ecstatic customers because they become repeat customers. And we do hate to disappoint.

Goals, Objectives and Priorities

I mentioned 4 variable calculus above. Actually, it’s more like 5 variable calculus, the fifth variable being your goals and objectives for sharpening. Let’s examine those in more detail.

If satisfying curiosity are among your goals, then by all means try all the stones, sandpaper, films, pastes, jigs, contraptions, and machines available and methodically test them until they turn to dust. It simplifies the calculus, but the cost and time required to reach a final conclusion may become a heavy burden.

If beautiful blades, zen-like sharpening experiences, and improved hand-soul coordination are high among your ojectives (they’re included in mine), then you will want to try natural finishing stones. I heartily recommend them to those who have reached a certain level of skill with synthetic stones and are willing to roll the bones.

The performance of the sharpening system you select, including the following factors, is something should include in your calculations:

  • Time efficiency: How long does it take you to produce an adequately sharp edge starting from a dull/chipped one? How fiddly is the process? For this calculation you will need to determine how much your time is worth. Remember, while you may enjoy sharpening, from the professional’s viewpoint, time spent sharpening is non-productive time because, during the period you are working on tools, your hands, eyes, and mind cannot work on the stuff you contracted to deliver to the Customer;
  • Cost efficiency: How many billable hours and expensive supplies/tools/equipment must you expend to obtain an adequate cutting edge? For this calculation you will need to determine the cost of time, consumables (stones, sandpaper, film, paste, powder, beer) and equipment (grinders, jigs, plates, widgets, etc.) expended in producing an adequate cutting edge long-term. Even if you are not getting paid for your woodworking, your time still has value. And don’t forget to depreciate the cost of stuff. This is where synthetic waterstones shine in comparison to the many other sharpening systems out there.
  • Cutting efficiency: How well and how long does the sharpened blade cut? For this calculation, you need to determine what an “adequate cutting edge” is for you. For instance, given the same abrasives and expending the same amount of time to sharpen two blades, the blade with a rounded bevel, or even multiple bevels, is seldom as sharp as the blade with a simple flat bevel, as can be readily confirmed using a powerful loupe or microscope to examine the last few microns of the blade’s effective cutting edge (more on this subject in Part 21 of this series). Does the sharpening system you are testing tolerate or even promote bulging bevels or multiple bevels? Get out your loupe before your inner troll makes you say things you will regret.

If curiosity, pleasure and beauty are lower priority than practical performance in your list of objectives, then I suggest you focus on synthetic waterstones and the bedrock basics, at least for now:

  1. Obtain a minimum set of basic synthetic stones, or adapt what you already have;
  2. Learn how to use them skillfully;
  3. Practice those skills until they seep into your bones.

It is not an expensive process, but neither is it the instant short-term sort of thing the Gurus of Sharpening offer in their books and DVDs and classes through their tricks and gimmicks. It takes real skills that will serve you and your tools well for your entire life. And it all starts with the minimum set of stones.

The Goldilocks Set

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Oh my goodness, just look at the time! I really must be going.

Sharpening stones are expensive consumables that disappear a little with every stroke. If you need more than 5 minutes to sharpen a plane or chisel blade that was not chipped or damaged, then you may be spending too long, and wasting your time and stones, so it’s important to determine the bare minimum set of stones that work best for you.

The Goldilocks set I recommend includes the following 4~5 stones/plates:

  1. A Rough Stone: 400~800 grit rough diamond plate or two carborundum stones;
  2. Medium Stones: Two 1,000 grit waterstones (I will get into the reasons for having two stones of the same grit in another post);
  3. A Finish Stone: 6,000~8,000 grit waterstone.

Please also note that I don’t take 10,000+ grit synthetic finishing stones or natural fine-finishing stones to jobsites. This decision is based on simple practical experience: Jobsites are rough and dirty places, and stones are fragile. 

But there is an even more important reason: Airborne dust at jobsites will instantly degrade an expensive 10,000 grit rated stone to an effective 4,000 grit or less in an instant, making ultra-fine grit stones pointless. Dust will be the subject of the next post in this series.

The sharpening stones I normally use in the shop include a few beyond the minimum set described above. This set includes more stones, but the idea is that this finer gradation creates a better-quality cutting edge while consuming less of my expensive finishing stones. Natural stones can be pricey:

The packaging is fancier, but the content’s the same.
  1. One 400~800# diamond plate or two rough carborundum stones (only occasionally necessary);
  2. Two 1000# Imanishi waterstones (Bester brand) (usually necessary, but sometimes I skip it);
  3. Two 2000# Bester waterstones;
  4. One 6000# stone (fine enough for quickly finishing chisels and most planes);
  5. Two natural stones for finish planes and push chisels, or just for fun (a 10,000# synthetic stone works just as well).

Which Brand of Synthetic Stone?

I don’t think there is a dime’s worth of difference between the various synthetic stone manufacturers except for their marketing and distribution. I use what works for me and is available locally at the cheapest price. We don’t sell stones and have no relationship with or loyalty to any manufacturer. 

Regardless of manufacturer, I do recommend you avoid the extra-thick variety of synthetic stone because the oven’s heat sometimes does not penetrate deep enough leaving the interior too soft.

The Most Important Stone

Everyone focuses like a laser on the finishing stone, the final stone in the process, but when sharpening a particular blade, the most important stone is really the first stone you use in the series, be it a 400 grit diamond plate or a 2,000 grit waterstone. 

You may find this whole discussion passing strange, so I will explain. The roughest stone (or diamond plate, depending on the amount of steel that must be wasted and your available time and budget) you begin the sharpening process with builds the foundation of your cutting edge by performing the following two critical tasks:

  1. Removing damage at the cutting edge; and
  2. Shaping/flattening the cutting bevel.

Only a rough stone (400~800 grit) can accomplish the first task efficiently. If the truth of this statement is not self-evident, I won’t even try to convince you. Do the comparisons yourself: count strokes, time, and cost, measure angles, and peep at scratches through a high-power loupe.

In addition, your roughest stone or diamond plate is also the most efficient tool for shaping the bevel and cutting edge, if it needs to be adjusted. Until these two critical tasks are completed, none of the subsequent finer stones can accomplish anything efficiently, and the faster and more precisely these two tasks are accomplished the sooner one can stop sharpening and get back to the real job of woodworking.

The role of the finer stones in the sharpening sequence is simply to replace the deeper scratches left by the preceding rougher stone with progressively finer scratches. And since this work is done using more expensive, less-abrasive and slower-working stones, it is most cost/time-efficient to accomplish this task as quickly as possible. If you knock out the two foundational tasks listed above using your rough stone/plate well, then you can accomplish the subsequent polishing work at minimum cost and maximum speed. Screw it up and your blades will hate you.

Please be sure you understand the meaning of the previous 4 paragraphs. They are the heart of this article

So how does this work in real life? If the blade is chipped, dinged, or needs shaping, then I start repairing and reshaping the cutting edge’s foundation with my diamond plate. A carborundum stone, if very flat and kept flat, will work too. If my blade is only dull, but not damaged, and the bevel is in good shape, I start with a flat 1,000 grit stone. If the blade is starting to lose its edge, but is not damaged and still cuts, I start the process with a flat 2,000 grit stone. Notice the word “flat” is used a lot in this paragraph.

The objective, again, is to create an adequately sharp edge in the minimum amount of time and cost by starting the sharpening process with the cheapest, most aggressive stone appropriate to the blade’s condition for the heavy wasting and shaping thereby creating a bevel and cutting edge which you can then quickly polish to the final cutting edge using the more expensive, finer-grit stones. Wow, that’s a mouthful!

I want to make one thing perfectly clear before ending this post. Except for a few special situations, I don’t recommend using secondary bevels or micro-bevels except in special circumstances because, like training wheels on a bicycle, they are not an efficient long-term solution. In fact, they are a short-cut that has stunted many people’s sharpening skills. We will return to this subject later. 

YMHOS

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The Marketing Department

Links to Other Posts in the “Sharpening” Series

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

Sharpening Part 12 – Skewampus Blades, Curved Cutting Edges, and Monkeyshines

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

If you have private questions or would like to learn more about our tools, please use the questions form located immediately below. Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” Your information will remain confidential (we’re not evil Google or incompetent facebook).

Sharpening Part 13 – Nitty Gritty

“The true mystery of the world is the visible, not the invisible.” 

Oscar Wilde

In this post we will dig into a few important nitty gritty points about sharpening stones everyone needs to know. Perhaps you already know all these points, but please ready your shovel because there may be at least one buried surprise.

A Flea’s-Eye View

When seen under high-magnification, the surface of a sharpening stone looks like millions of densely-packed stones embedded in a flat field. The smaller the stones, the finer the grit.

As the blade is pushed and pulled over these stones, they scratch and tear metal from the blade’s surface leaving behind scratches corresponding to the size of these small stones. This violence continues until the blade’s ura and bevel form a clean intersection of two planes.

A view of a blade sharpened with 1200 grit diamond plate showing the furrows left by individual pieces of grit

Seen under high-magnification, the cutting edge is jagged where these furrow-like scratches terminate at the cutting edge. To some degree, it may even look like a serrated sawblade. Some blades, like kitchen knives and swords, are used in a slicing motion to cut soft materials like meat and vegetables and enemy arms, and their performance benefits from a serrated cutting edge more than a highly-polished edge, and so do not need to be highly polished on fine-grit sharpening stones. 

Plane and chisel blades, however, are used to cut wood, a material typically harder than foodstuffs, in a straight-on direction, not in a slicing motion, for the most part. In this situation, a rough, serrated cutting edge is weaker than a highly polished edge because the jagged edges are projecting out into space like the teeth of a handsaw blade, and are relatively unsupported and more easily damaged than a highly-polished blade with smaller, more uniform scratches terminating more cleanly at the cutting edge. 

Therefore, in order to produce a sharp durable blade, we must make the microscopic cutting edge smoother and more uniform by using progressively finer grit stones to produce shallower and narrower scratches, and a thin, uniform cutting edge.

But how fine is fine enough? There is a curious phenomenon related to friction that is applicable to cutting edges, and is useful to understand. 

The Friction Paradox

Imagine a cube of heavy stone with its downward flat face resting on the level, flat surface of a larger slab of similar stone. Let’s say it takes some specific measure of force pushing horizontally on the stone cube to overcome the static force of friction between the two stone surfaces in order to make the cube start moving. 

If we gradually increase the degree of polish between the two contact surfaces and measure the force required to start the cube moving at each progressively higher level of polish, we will find the force decreases with each increment of increased polish, for a time. This is at least partially because the irregularities between the two surfaces (asperities) do not interlock as deeply when the surfaces become more polished. 

However, at some point, more polishing brings the surfaces of the two stones into such intimate contact that the molecular attraction between them, and therefore the force necessary to move the cube, actually increases. 

The Inflection Point

The same phenomenon occurs with tool blades. If you sharpen and polish your blades past a particular point, the friction and heat produced between blade and wood will increase, as will the energy that must be expended, while the resulting quality of the cut and durability of the cutting edge will not improve significantly. Of course, the time and money invested in stones spent sharpening past this point will be mostly wasted.

The inflection point where additional polishing yields increased friction with little improvement in cut quality will depend on your tool and the wood you are cutting, but you can gain a pretty good idea of where it is if you pay attention over time. While the sharpening stone manufacturers hate my saying it, in my well-informed opinion there is little practical gain, beyond self-satisfaction, to be had from sharpening chisels or planes past 6,000~8,000 grit, making this range of grit an inflection point in my mind. What about you?

Conclusion

I encourage you to conduct your own experiments to determine the inflection point in the case of your planes and wood you cut. Many who figure this out save themselves significant amounts of time and money sharpening over the long-term.

To those of our Gentle Readers that love sharpening more than woodworking, and enjoy putting money in the pockets of sharpening stone manufacturers more than keeping it for themselves, I apologize for pointing out the floater in the punch bowl. But you probably would have it noticed it eventually anyway, if only from the taste difference.

I will touch more on this important point in the next exciting installment in this scientificish adventure.

YMHOS

Links to Other Posts in the “Sharpening” Series

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

Sharpening Part 12 – Skewampus Blades, Curved Cutting Edges, and Monkeyshines

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or profitably “misplace” your information.