Sharpening Part 29 – An Example

The expectations of life depend upon diligence; the mechanic that would perfect his work must first sharpen his tools.

Confucius

This is the final post in our series about Sharpening Japanese Woodworking Blades, in which I will try to bring all the information provided in the previous posts together into a single practical example. That does not mean the entire contents of those posts is repeated here, however, so please refer to the previous articles if things become confusing. I have provided some links in the text, and provided links to all the articles at the end.

But before we dive into our practical example, I would like to create some context.

Paying Debts

The purpose of this blog, as I have mentioned before, is not to sell stuff or attract clicks but to help our Beloved Customers increase their knowledge and improve their skills in maintaining and using the high-quality hand-forged professional-grade woodworking tools we purvey.

Another purpose is to pay a debt of the kind that can’t be recorded on paper, only in the heart.

In this series of posts I have carefully NOT promised quick and easy results, nor have I given abbreviated explanations or promoted dumbed-down techniques tailored to fit neatly within the publishing parameters of a book, magazine article, or a pretty little video. This is because the series is not about me, or my skills, or what I think is best, or selling stuff but rather helping our Beloved Customers obtain real long-term results and life-long skills of the sort expected of professional Japanese woodworkers. And since I can’t instruct them directly, our Beloved Customers must truly understand the principles and techniques so they can train themselves. Fragmentary instructions and short-cuts would be far easier to write about, but wouldn’t help with that training.

I share many experiences in common with most of our Beloved Customers, but I’ve also had some unusual experiences working with and being mentored by extremely accomplished Japanese professional craftsmen including sword sharpeners, tool sharpeners, carpenters and joiners. None of those gentlemen charged me a notched nickle for the things they taught. Likewise, I have never sought compensation for teaching others those same techniques. And so we come to the other reason for this series, namely to pay those gentlemen back for the time they spent and the kindness they showed me.

So gird up your loins, recall the information and techniques presented in the previous 28 posts in this series, and let’s sharpen a blade.

Removing Damage and Correcting the Bevel

We will not even try to deal with all the possible starting points for sharpening a woodworking blade. In this example we shall assume the lands surrounding the hollow-ground area at the blade’s ura are already flat, planar, and polished. If your blade is not in this condition, follow the instructions at the end of this section. We shall also assume the edge has a small chip that must be removed first. These conditions will cover 80% of sharpening jobs.

Richard Kell 625-3000 Brass Bevel Gauge
Richard Kell 625-3000 Brass Bevel Gauge

If the blade’s cutting edge bevel angle is where you want it to be, the bevel is already flat, and the blade isn’t damaged, please skip to Step 11 below.

1. Examine the Bevel Angle: Check the bevel angle with your bevel angle gauge. 27.5° ~ 30° for plane blades, 27.5° ~ 35° for oirenomi and atsunomi. No less than 24° for paring chisels.

2. Correct the Bevel Angle: If, based on the check in the previous step and the blade’s actual performance, you determine the bevel angle needs to be adjusted, correct the bevel angle using your 400~800 grit diamond plate or FLAT carborundum stone either free-hand or using a honing jig like the Lie-Nielson product, the Eclipse jig, or whatever catches your fancy. If you use a honing jig, you may want to add a drop of oil to the moving parts before they get wet. Be careful to avoid making skewed or curved (cambered) cutting edge unless that is specifically what you need.

3. Examine the Edge: Examine the blade by eye and touch. Stroke the edge with your thumb (over and away from the edge not into the edge!) to confirm its condition, and run a fingernail along its length to check for defects as described in the previous post in this series. Your fingerprints will snag on any rolls or burrs, and your fingernail will detect irregularities invisible to the eye. Assuming there is some minor damage, go the next step. If there is no damage, the bevel is in good shape, and the blade is just dull, skip to step 11 below.

4. Remove Damage: Remove chips and dings from the cutting edge by standing the blade, cutting edge down, on a flat 1000 grit stone, with ura facing away from you, tilted a few degrees from vertical towards you, and pull the blade towards you without applying downward pressure. Usually one or two strokes will suffice. The goal is to remove damage by creating a flat at the cutting edge. Examine the flattened edge with eye, fingertip, and fingernail to see if the chip or defect has been removed. Repeat until it’s gone. Don’t overdo it. Whatever you do, don’t allow the blade to become skewed! This method takes a bit of courage the first time, but it is the quickest, surest, and most economical way to get the job done.

5. Clean the Blade: Carefully clean grit and mud from the blade and the honing jig’s wheel (if you use one) to prevent contaminating the next stone. This is important.

6. Check and Color the Bevel: Check the bevel frequently to confirm full contact. You might blacken the bevel with a marking pen or Dykem to make it easier to monitor progress. This step is worth repeating between stones because it is helpful in monitoring what you cannot see otherwise.

7. Sharpen on the Rough Stone: This is the most important stone in the process. Now that all the damage has been removed and the bevel is in good shape, we need to abrade the bevel until the flat we made in step 4 is gone and we have created a tiny, clean burr. Sharpen the blade’s bevel on your roughest diamond plate or FLAT carborundum stone. If sharpening freehand, take short strokes. Always use the entire face of the stone, including corners, edges and ends as described in the previous post in this series. Turn the stone end-for-end frequently to compensate for your natural tendency to work some areas of the stone harder than others. Watch the edge carefully to make sure the width of the flat made at the cutting edge in Step 4 above gradually decreases in width evenly along the cutting edge’s length. If the flat becomes narrower at one corner than the other, apply extra pressure at the wider side, or hang the corner of the blade’s narrower side off the stone for a few strokes to correct. Stop when the flat is gone, and a clean, uninterrupted, but barely detectable burr is created. With practice, you should be able to do this without a honing jig. When using all the stones and plates in this process, keep them wet at all times, and add water as necessary. If the stone becomes dry, not only will it clog and stop cutting efficiently, but friction may cause localized heating of the thin metal at the cutting edge softening it. Remember, you’re tearing metal from an extremely thin cutting edge. You cannot see it and your fingers cannot feel it but this destruction heats up metal at that thin edge.

8. Check the Burr: Your fingertip will feel the burr long before your eye can see it. Stop when you have a small, uniform burr without interruptions the full width of the blade. Confirm this with your fingernail. Anything beyond this is just wasting metal and stones. With practice, this process will go very quickly, and you can move onto the next stone while the burr is barely detectable.

9. Create Skewed Scratches: When you have a uniform burr, work the blade sideways, or at an angle, on the stone to create diagonal scratches on the bevel removing the straight-on scratches the stone produced.

10. Clean the Blade: Wipe and wash the blade (and the honing jig’s wheel, if you are using one) to remove grit and mud. This is very important to prevent contamination of finer-grit stones. 

At the conclusion of step 10, the bevel will be flat, uniform, and at the correct angle. The flat created during step 4 above will be gone, and you will be able to just detect a full-width tiny burr using your fingers. 

For the next steps, keep the blade attached to the honing jig if you used one in the previous steps. Otherwise, sharpen freehand if you can. Don’t let the honing jig become a crutch that slows you down and prevents you from developing control.

Normal Sharpening Procedures

This is where the sharpening process normally starts when the blade is not damaged and the bevel is in good shape but only needs to be sharpened. It usually does not include a honing jig which can only slow things down.

11. Check and True the Medium-Grit Stone: You may decide to use more than one medium grit stone. I always use a 1000 grit, and often use a 2,000 grit stone as well. Whatever you use, it must be clean and flat. As described in previous posts, you need to check your stones flatness frequently with a stainless steel straightedge. To do this, wash any mud off the stone and pad (don’t rub) the stone’s face dry with a lint-free clean cloth or paper towel. Hold the stone up to a light source, place the straightedge along the stone’s length, across its width, and across its diagonal and check for light leaking between stone and straightedge. Make a pencil mark, such as a line or circle, on high spots using a wide carpenter’s pencil. Once you understand if and how the stone is distorted, flatten it using whatever method you prefer, a diamond plate, a specialized truing block, or my preferred method, another stone of the same grit. If you use my way you won’t need to worry about grit contamination and can save time and money by truing two stones at the same time. Six of one, half-dozen of the other.

12. Sharpen on the Medium-Grit Stone(s): Work the bevel on your medium-grit stone in short strokes using the stone’s entire face from side to side, end to end, and corner to corner, turning the stone end-for-end frequently and being careful to avoid rocking the blade. A bulging bevel is bad news, Bubba. You will know you are done with this stone when all the diagonal scratches from the previous stone, especially at the extreme edge, have been removed. The burr may or may not have disappeared by now. Check with your fingerprints and fingernail. If it still remains, it should be just barely detectable. If it is still big, you need a few more strokes on this stone to shrink it. Using a loupe at this point will be informative. End your work on this stone by creating some new diagonal scratches on the bevel erasing all the previous straight scratches.

You may want to repeat this step using another medium-grit stone, such as 2,000 grit, to save wear on your finishing stones. Either way is fine.

13. Clean the Blade: Wipe and wash the blade (and the honing jig’s wheel, if you are using one) to remove grit and mud. This is very important. Remove the honing jig at this point if you have been using one.

14. Polish on the Finishing Stone: Move onto your finishing stone, usually a 6,000~8,000 grit synthetic stone. This may not be the final finishing stone you use. Be sure it is flat, uncontaminated with grit from rougher stones, and wet. You may want to use your nagura stone to create a slurry from the stone’s corners and edges that will accelerate the polishing process. The finishing stone serves a polishing function, and because it’s grit is so fine, it lacks the ability to distort the bevel badly, so you can take longer strokes and polish the blade on both the forward and return strokes. When all the diagonal scratches from the previous stones are gone, you are done with this stone. If there is still a burr left after the medium-grit stone, it should have evaporated by now. If not, the burr was probably too big to begin with and your technique needs refinement.

15. Examine the Bevel: Take a good look at the polished bevel. Are there still scratches left from the previous stone? This may be because you did not remove all the scratches from previous stones. Or it could be because this stone or previous stones in the series were contaminated with dust or rougher grit. If so, you should figure out why and correct that problem before the next sharpening session.

16. Polish the Bevel Using the Final Finishing Stone: This step may not be necessary, depending on the time available, the degree of sharpness required, and your inclinations. This extra polish probably won’t make a significant difference in the cutting tool’s cutting performance so is often abbreviated during a busy work day. If you use a natural finishing stone or a 10,000+ grit finishing stone, this is the time to use it. Simply repeat the process in step 14 above, but be sure to apply light pressure, keep the stone at least a little wet, and sharpen on both the push and pull strokes.

17. Polish the Ura: With the bevel polished as finely as you intend it to become, polish the ura on the final finishing stone only. Place the last 1/2” of blade’s length on the stone’s edge (the stone MUST be flat) with the cutting edge parallel with the stone’s length, and the rest of the blade hanging off the stone but supported by your right hand. Press down on the bevel with two or three fingers of your left hand. Be sure to apply even pressure with these fingers. These fingers press down only and do not push the blade. The right hand pushes the blade back and forth and onto and off-of the stone. Take light strokes focusing pressure on the extreme cutting edge, but without lifting the blade’s head.

18. Polish the Bevel (Again): After several strokes on the ura, polish the bevel.

19. Alternate Between Ura and Bevel: Go back and forth polishing the ura and bevel, but keep in kind that you want to limit the number of strokes on the ura side (assuming it’s already highly polished as discussed above).

20. Examine the Edge: Check the full length of the cutting edge frequently with your eyes, fingertips and fingernail. The burr should be gone entirely. The edge should be sharp, and absolutely smooth. All the rougher scratches from previous stones should have disappeared. I make a final sharpness test by shaving an ultra-thin slice of skin from a callous on a finger allowing my bones to sense the degree of sharpness. This method is much more accurate than shaving hair off the arm. If you try it please don’t draw blood.

21. Clean, Dry and Oil: After you are done sharpening the blade, rinse it with clean water or sharpening solution (Item 5 in Post 17) and wipe it dry on a clean cloth or paper towel. You may want to strop it lightly on a soft clean cloth (or the palm of your hand, if you are confident in your abilities) to remove hidden water. I recommend applying a spray liquid rust preventative to the blade that displaces moisture, such as CRC Industries’s 3-36 or WD-40. CRC3-36 is paraffin based, floats water out of the blade’s nooks and crannies, and leaves a film that will prevent corrosion long term. However, please note that, while WD-40 is very convenient and displaces moisture, it evaporates entirely and is therefore not adequate for long-term corrosion protection. If you are going to use the blade right away, a little oil from your oilpot is cheaper, more convenient, and will do the job just fine.

With practice, and assuming you have not let your stones become too distorted, this entire process from Step 1 should take no more than 10~15 minutes. This assumes the blade is chipped or damaged and you need to correct the bevel or use a honing jig. Honing jigs slow the process down but are convenient when using rough stones and coarse diamond plates.

If the blade is in good shape and just needs normal sharpening, the goal should be 5 minutes from the medium grit stone in step 11. If you can’t do that quickly right away, don’t rush, just practice and get a little quicker each time: Slow is smooth; Smooth is fast.

Note: If you are sharpening a new blade, or the ura needs to be trued and/or repaired, work the ura on all the stones used in the steps above, but be careful to limit the number of strokes on the rougher stones to the absolute minimum. Also, instead of keeping just 1/2” of the blade’s length on the stones, move it diagonally in and out towards the blade’s center to prevent the stones from digging trenches in the ura. Use special care during this process.

I recommend covering at least your finishing stone with something when you are not using it to protect it from contaminating dust. I simply wrap mine in a sheet of newspaper. It doesn’t take any time or money. Some stones prefer to read the sports pages, others prefer current affairs. Just ask them.

Conclusion

I am confident the techniques described in this series of posts will prove useful if sharp tools matter to you. Your tools may not talk much, but if you train yourself in these techniques I promise they will sing their appreciation.

I trust the gentlemen that taught and mentored me would be pleased with the content in this series of articles, although I doubt they have time for reading nowadays. I will ask them when I see them again in the big woodpile in the sky.

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

Sharpening Part 28 – The Minuscule Burr

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 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 28 – The Minuscule Burr

Sharpening Part 29 – An Example

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

Related image
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 29 – An Example

Sharpening Part 24 – Sharpening Direction

Related image

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 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 28 – The Minuscule Burr

Sharpening Part 29 – An Example

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 28 – The Minuscule Burr

Sharpening Part 29 – An Example

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

Sharpening Part 28 – The Minuscule Burr

Sharpening Part 29 – An Example

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 16 – Pixie Dust

Ashes to ashes, dust to dust, if the women don’t get you then the whiskey must.

Carl Sandburg
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In the previous post we examined sharpening stones, the minimum set I recommend, those I typically use, and the most important stone in any set. In this post we will shift our focus to things that can go wrong when sharpening, including supernatural influences.

Dust Contamination

As I mentioned in the previous post in this series I almost never take a 10,000+ grit synthetic finishing stone or natural finishing stone to jobsites. This decision is based on observation under practical conditions: Jobsites are rough and dirty places, and stones are fragile. 

Iron Pixies are rabid fans of Lingerie Football. Don’t hang posters or watch games in your workshop if you want to avoid crowds of the tiny beer-drinking fiends.

Even if Murphy is drunk and the Iron Pixies are distracted watching Lingerie Football on the boob tube (pun intended), airborne dust at the jobsite will always instantly degrade an expensive 12,000 grit rated stone to an effective 4,000 grit or less in an instant, making a fragile, expensive, ultra fine-grit stone pointless. How clean is your workplace? Something to think about. Seriously.

This is not just a theory that sprouted from my overactive imagination like a dandelion on a dung pile, but is scientifically verifiable. Give it try.

Get out your microscope or high-power loupe. Place a clean glass slide near where you will be sharpening. 60 minutes later, examine the slide and count the dust specks. How did they get there? Dust is in the air quite naturally, but vehicular and foot traffic kick up lots more.

Most of those dust specs are larger and harder than the grit that makes up your finishing stone. Imagine what happens to your blade when those pieces of relatively large, hard grit get mixed into the stone slurry, or become embedded into the stone’s surface. Not a pleasant thought.

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Dust contamination even has historical precedence. Japanese sword sharpeners traditionally do their best work during the rainy season when there is less dust in the air to contaminate their stones. 

Professionals that polish pianos, stone, glass and jewels are also sticklers for eliminating dust contamination.

Just design and build a few cleanrooms for picky customers with SEMs (scanning electron microscopes), or with lens coating equipment, or who make pharmaceuticals and you will get an education about dust and the problems it creates quickly.

What dust do we find at construction job sites or workshops? First, assuming we are working at a building project, there are exterior sources of dust. Unlike a house, the doors and windows are usually open to gain maximum circulation, even when dusty landscaping operations are ongoing and trucks carrying materials and garbage are running everywhere kicking up clouds of dust.

effects of dust on lungs

Second, unless you have the jobsite entirely to yourself, there are usually other trades inside the building grinding, sanding, cutting and walking around kicking dust into the air too. The most pernicious dust on the jobsite is drywall and joint compound. This white fluffy dust appears harmless, but it contains tiny granite silica particles harder than steel, that float around and settle on everything. They are a health hazard that has put more than one person in the hospital with respiratory problems. They will contaminate your sharpening stones.

Sandpaper, sanding discs, grinders and angle grinders also spray millions of tiny hard particles everywhere, many of which float in the air and can travel some distance before settling, especially inside an enclosed building or workshop.

dangers of dust on site

Does your business or home workshop have a large door facing a public road with cars and trucks going back and forth? Do people with muddy boots come in and out? Are dirty pallets with piles of dirt hidden on the bottom boards offloaded inside? Do you use sanders or grinders in your workshop?

If you are sharpening outside, or at a dusty jobsite, or inside a dusty workshop, and especially if you regularly use sanders and grinders there, I recommend the following procedures before you use fine-grit stones:

  1. Try to locate your sharpening area away from foot traffic, grinding and sanding operations, and dusty areas;
  2. Sweep the surrounding floors well, since it is the movement of feet that billows settled dust back up into the air, and wait at least 15 minutes after sweeping for the dust to settle before sharpening;
  3. Wet the surrounding ground or floor with water to keep the dust down (this makes a big difference);
  4. Lay a clean cloth or a sheet of clean newspaper over your fine stone when you are not using it for more than a couple of minutes to prevent airborne dust from settling on it;
  5. Keep your fine stone wrapped in a clean cloth or newspaper when you are not using it;
  6. Scrub your fine stone under running water with dishwashing soap (neutral PH) and a clean natural-bristle brush before each use to remove dust and embedded grit.

And for heaven sake, even if you can’t take your benchdogs with you everywhere, at least have a brass bevel angle gauge in your toolkit, and use it everytime you sharpen, to keep the pernicious pixies at bay. I hang mine around my neck from a red string, red because all species of the Little Folk strongly dislike that color. It’s no coincidence that Iron Pixies take great joy at turning valuable tools red.

The following are few references regarding silica and construction dust: Silica-Safe.org Center for Disease Control. Makes you want to wear a respirator in bed.

The legal team hard at work digging up dirt

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

Sharpening Part 28 – The Minuscule Burr

Sharpening Part 29 – An Example

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 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

Related image
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

This image has an empty alt attribute; its file name is tenor.gif
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

Sharpening Part 28 – The Minuscule Burr

Sharpening Part 29 – An Example

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

Sharpening Part 28 – The Minuscule Burr

Sharpening Part 29 – An Example

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 12 – Skewampus Blades, Curved Cutting Edges, and Monkeyshines

Even monkeys fall from trees (猿も木から落ちる)

Japanese saying
A famous wood carving of 3 monkeys located at Nikko Toshogu Shrine post resconstruction that illustrates a famous saying originating in China that also works as a pun in the Japanese language. From right to left: See no evil; Speak no evil; Hear no evil (見ざる、聞かざる、言わざる).

Ideally, a tool blade will have absolutely uniform dimensions: the right thickness and taper, perfect cross-sections, uniform curvature, and straight edges and surfaces. However, professional grade Japanese tools are not made on CNC machines, but are hand forged, and have dimensional imperfections. Indeed, imperfections are part and parcel of all human endeavors. Most imperfections don’t matter; Sometimes they make the tool better; Other times they need to be remedied.

You, Gentle Reader, may not notice that the blade or cutting edge of one of your chisels or planes is “skewampus,” and consequently the cutting results are less than ideal. You may blame those poor results on your technique in using the tool or the irregular wood grain, when the real problem is the shape of the blade’s cross-section, or your unintentionally sharpening the blade with a skew. We will examine this problem in this post.

We will also look at the curved or “cambered” cutting edge profile in plane blades, the benefits and undesirable results it can produce, and how to incorporate this blade profile intelligently into your woodworking repertoire.

Many people, like monkeys in trees, learn bad habits from their friends and teachers. We hope this post will help you understand what is going on with your woodworking blades, and how to shape and sharpen them intelligently instead of just monkeying around. Please be sure to BYOB (bring your own bananas).

A serious craftsman doing Fine Woodworking in a Pixie-free workshop (notice the strategically-placed boots).

Dealing With Skewampus Blades

Skewampus is an interesting word I learned from my mother. I am told it is a combination of the word “Cattywampus” meaning “in disarray,” and “askew.” I think it is the perfect word for describing the ailments some blades suffer.

While less than ideal, it is not unusual for the thickness of a chisel blade’s cross section to vary slightly across its width, with one side being thicker than the other, forming an irregular quadrilateral cross section. This irregularity is found in plane blades too, but it is not typically a problem. Since there is more steel on the thicker side, the cutting edge will tend to develop a skew during sharpening.

Japanese plane and chisel blades are formed by laminating a layer of hard steel to a much softer body made of extremely low-carbon steel or iron. If the lamination exposed at the cutting edge is not uniform, the area of the blade with more hard steel touching the sharpening stone will abrade slower than areas with less exposed hard steel such that the cutting edge will tend to become skewed during sharpening. Perfection is not required, but the uniformity of the lamination is an important detail to observe when purchasing Japanese tools.

Likewise, Western plane and chisel blades that are not uniformly heat-treated, and that exhibit differential hardening across the bevel’s width, will also tend to become skewed during sharpening as one side of the bevel abrades quicker than the other. This problem is more common than you might imagine, especially in the case of inexpensive tools where appearance and low price are given higher priority than quality.

Anyone that has experience bidding high-dollar construction projects will understand the statement “the most profitable job may be the one you lose.” Cheap tools are much the same way: that low-cost chisel or plane may look good on paper, but if you count your time worth anything, if you dislike headaches, and real-world performance matters to your bottom line, then such a tool is often disastrous. Caveat emptor, baby.

A chisel or plane blade that has an irregular cross section or a skewed cutting edge may not be a problem for many cutting operations. However, when cutting mortises, a chisel blade with a skewed cutting edge or irregular cross section will tend to drift to the side gouging the mortise’s walls and ruining tolerances. If you find that your mortise walls are gouged, or that tolerances are poor, check your chisel blade’s shape, and correct any deformities.

Like all human work spaces, Japan’s smithies are not immune from pixie infestation despite annual blessings by Shinto priests and periodic offerings of rice, salt and wine to the spirits. In a previous post we discussed supernatural predators, so I will refer you to it for antidotes to pernicious pixie pox. But the deformities we are examining in this post are more often the natural result of the human eye misjudging hammer blows or non-judicious use of grinder wheels rather than precocious pixies at play.

If your blade’s deformity is not excessive, you can compensate by applying a little extra pressure on the blade’s thicker side while sharpening it. 

It is interesting how a little off-center pressure on a blade being sharpened over many strokes can change its shape. Many people unintentionally deform their cutting edges by not paying attention to the amount and location of the pressure their fingers apply. A word to the wise.

Another potential solution is to skew the blade in relation to the direction of travel when sharpening the bevel. This works because the leading corner of a skewed blade is abraded quicker than the trailing corner. But once again, inattention causes many people to skew their blades when moving them around on their sharpening stones unintentionally creating, instead of intentionally correcting, skewed cutting edges. There is nothing wrong with skewing the blade when sharpening so long as you are aware of the distortion this practice can produce and compensate accordingly. Another word to the wise.

If these methods don’t compensate adequately, you may want to grind and lap a chisel blade to a more uniform cross-sectional shape. A chemical bluing solution used afterwards will help conceal the shiny metal exposed by this operation if your chisel objects to the shiny spots. Some of them can be quite vain, you know.

A chisel with a an adequately uniform lamination and cross-section, and nice polish.

Cutting Edge Profiles

Many people have access to electrical jointers and planers, but relatively few have industrial equipment with the capacity to dimension wide boards such as tabletops. And of course architectural beams and columns are typically too long or too heavy to dimension with most stationary electrical equipment.

The choices available to most people for dimensioning such materials therefore are either handheld electrical power planers and/or sanders, or axes, adzes and hand planes. Powerplaners, sanders, axes and adzes are beyond the scope of this article, but we will look at hand planes.

I need more than one plane? You can’t be serious!

Although the very idea gives some woodworkers vapors (I don’t mean gas), an efficient craftsman will have multiple planes with cutting edges honed to profiles matched to specific operations.

Everyone that dimensions larger pieces of lumber by hand needs a plane with a wide mouth and a curved or “cambered,” cutting edge called a “scrub plane” in the West, and “arashiko kanna” in Japan.

This variety of plane excels at hogging a lot of wood quickly when the craftsman needs to significantly reduce the thickness of his lumber.  If the blade is narrow and curvature is deep, this plane will hog wood quickly, but leave a deeply rippled surface, often with bad tearout.

One might also have a second arashiko, or jack plane with a wider blade with a shallower curvature for the next steps in the dimensioning process. Such a plane will not hog wood as quickly, but it will produce a surface that is closer to flat and smooth and with less tearout. You can see the advantage of having two arashiko planes, or a scrub plane and a jack plane, with different cutting edge profiles when dimensioning lumber.

Many Gentle Readers use electrical-powered planes to dimension lumber before turning it into furniture, doors, chairs, or sawdust, etc. and are aware that planers always leave tiny ripple-like scallop cuts on the wood’s surface, along with some tearout. This will not do as a final surface. A hand-plane finish is far superior, but it doesn’t make sense to remove any more than the bare minimum of wood necessary to remove the washboard.

A finish plane is the perfect tool for this job on condition that it is sharp, set to a fine cut, the chipbreaker is tuned and set properly, the blade profile is appropriate for the width of the wood to be finished, and the wood does not have too many large knots. In one or two passes such a plane can easily remove the ripples and leave the wood clean and shiny without changing its dimensions much at all.

Assuming the wood is cooperative and one knows how to sharpen and setup their plane properly, blade profile frequently remains a key factor many fail to grasp. Obviously, the curved cutting edge of a scrub plane cannot produce the perfectly flat surfaces required for joining two pieces of wood together. On the other hand, the corners of a perfectly straight blade will leave clearly visible steps or unsightly tracks on the surface of a board wider than the blade, which is not a problem when rough dimensioning a board, but is painful to see if the board’s surface is to be left with just a planed finish.

So how do we solve this conundrum? When finish planing, the professional approach is to use two planes each with a different cutting edge profile. The first type of finish plane has a perfectly straight cutting edge used to plane pieces narrower than the blade’s width. Since the blade’s corners are not riding on the wood while cutting it, they won’t leave tracks and ridges.

The second type of finish plane found in the professional’s toolkit has a curved cutting edge, or more correctly, curved just at the corners to prevent it from leaving tracks and ridges when planing boards wider than the blade. Nearly all the edge is left straight, but creating this tiny amount of curvature at the right and left corners causes it to smoothly disappear into the plane’s mouth so no tracks are made and any ridges are nearly impossible to see or feel. In other words, the corners of the cutting edge never touch the surface of the board, and so don’t leave discernible tracks or ridges. The finer the cut made the smaller any ridges created will be. Indeed, where a high-quality surface is required, the final cut with the finish plane will produce shavings thin enough to see one’s fingerprints through.

You may want to reread the previous two paragraphs to make sure you understand what these two cutting edge profiles are and what they can accomplish before you read further.

Naturally, a professional doing high-quality work needs at least two finish planes, one with a straight cutting edge used to produce flat, precisely-dimensioned surfaces on wood narrower than the blade’s width, and another finish plane with a cutting edge very slightly curved at the corners used to finish wider surfaces.

There are those that advocate using a curved blade, sometimes dramatically “cambered” as some call them, for all applications. Those who teach this sloppy technique twist themselves into knots justifying tricks to approximate flat surfaces using such blades. I have no doubt this is an ancient technique, but I think it is a sad practice that sprung from the carelessness of some craftsmen in flattening their sharpening stones, and with time this bad habit became a tradition in some quarters. I strongly suspect fans of this strange way of doing business habitually sand all visible surfaces anyway so tracks and ridges are not a problem for them. But the fact remains that perfectly flat, track/ridge-free surfaces work best for joinery.

Tradition and “monkey see monkey do” are a useful place to start, but as his skill level increases, the thoughtful and efficient craftsman will eventually seek to confirm the validity of the traditions he has been taught. I urge you to get started early.

Sadly, too many people never notice the strange instruction label pasted to their boot’s sole, nor that smelly stuff sloshing around inside.(ツ)

monkey-see-monkey-do
Mommy monkey teaching baby monkey bad habits. When will they ever learn?

Conclusion

As we come to the end of this post, my advice to you, Gentle Reader, is to learn two bedrock basic skills to perfection. First, learn how to keep your sharpening stones flat; And second, learn how to sharpen your blades to have a straight cutting edge. Everything else will flow naturally from these skills. Your blades deserve it. We will talk more about these subjects in the future.

In this post, we have discussed 12 serious points about plane and chisel blades and how to use and improve them all but a few woodworkers in the West are unaware of, or ignore, but which are common knowledge among professional Japanese woodworkers in advanced trades. While condensed, it is enough information to fill a book, but we are giving it to you for the price of bananas (BYOB, remember?). We hope you picked up on each point, and test those that are new to you.

The next installment in this simian soap opera of sharpening will focus less on monkeyshines, and more on stones and techniques. Please stay tuned.

YMHOS

I can’t wait to read the next post!!

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

Sharpening Part 28 – The Minuscule Burr

Sharpening Part 29 – An Example

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