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

In this post in our series about Sharpening Japanese Woodworking Blades your always humble and obedient servant 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 their instruction. 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, but 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 diamond stones or FLAT carborundum stones 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 a 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 cutting edge with your thumb (over and away from the edge not towards the cutting 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 flat and in good shape, we need to abrade the bevel until the flat we made in step 4 is gone and we have created a minuscule, 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, so keep it cool with water.

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 diagonals to 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/stone, a specialized truing block, or my preferred method, another stone of the same grit. If you use my method 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 especially important at this stage in the sharpening process. 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 6,000~10,000 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. 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 the cause 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. The final 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.

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 mind 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 cheap, 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 it that quickly right away, don’t rush, just practice and get a little quicker each time: Remember the turtle with the sail: Festina Lente: 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’ll make the introductions, so let’s ask them when we meet again in the big lumberyard in the sky.

In the next and final article in this series, we will consider how to restore a worn-out ura in a plane (and maybe even a chisel) blade. Is there no end to the excitement?

YMHOS

If you have questions or would like to learn more about our tools, please click the see the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may Mama Shishi bite my head off.

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Sharpening Part 28 – The Minuscule Burr

Do the difficult things while they are easy and do the great things while they are small.

Lao Tzu

A key milestone Beloved Customer should aim for when sharpening a blade is the production of a “burr” at the edge when abrading the bevel (not the ura) using the first rough stone in the series. The formation of the burr indicates that the extreme edge of the bevel side of the blade has been abraded enough.

In this post in the Sharpening Japanese Tools Series, we will examine how to raise this burr and why it is important to do so, how to use the burr to test the condition of the cutting edge as you are sharpening, and how to transition from one stone to the next finest stone in the series

Raise a Burr

The steps in creating and then abrading away a burr. The size of the burr in step 2 is grossly exaggerated for clarity. Indeed, unless severe damage to the edge needs to be repaired, you should not normally be able to detect the burr by Mark 1 Eyeball alone.

Japanese plane and chisel blades tend to have harder steel at their cutting edges than Western chisel and planes, and consequently, their steel does not exhibit the plastic deformation necessary to readily produce large burrs, or “wires” as some people call them, when being sharpened. In fact, “burrs” on professional-grade Japanese chisel and plane blades may be difficult to detect.

The key point to remember is that the formation of a clean, uniform, smooth burr signals the elimination of all major defects, chips, and dents at the cutting edge. If there are a lot of deep defects to remove, the thickness of the metal at the edge that must be abraded is correspondingly greater, and the burr developed will tend to be correspondingly larger. But a large, loopy burr or wire is not desirable because it will tend to break off prematurely leaving a jagged, ragged edge that will actually set back the sharpening process.

You need to create a barely-detectable, tiny and clean burr as soon in the sharpening process as possible. My advice is to produce it by abrading the only the bevel side of the cutting edge on your roughest stone, although you may not be able to test if it is clean until after a few strokes on the medium-grit stone (1000 grit).

As we discussed in a previous post in this series, the way to keep the size of the burr minimal and the blade’s bevel flat is to focus the pressure of abrasion as close to the extreme cutting edge as possible, but without overbalancing and gouging the stone and dulling the edge. This is the most essential skill in freehand sharpening.

Now that we have a burr, let’s test it.

Testing the Burr

As you are working to produce the burr, you will need to quickly test its progress, but that can be difficult, if not impossible, to do by eye alone.

To make this process easier and quicker, rub the pad of your thumb or finger over the ura’s edge, away from the cutting edge, thank you very much, when using your rough stones. Your fingerprint ridges will snag on the burr long before you can see it. If the edge is chipped or damaged, the burr will not be consistent but will be interrupted at each defect. There is nothing at all to be gained and much to lose by allowing the burr to become larger than absolutely necessary, so pay attention.

Once you have produced a small burr the full width of the cutting edge and confirmed its existence, you then need to test it for defects. If you run your fingernail along the burr’s length (the width of the blade), you will feel interruptions in the burr long before you can see them. Keep working the blade’s bevel on the rough stone until the burr is consistent across the full width of the blade, and free of dents and chips.

In the case where you need to remove serious damage to the cutting edge, you may want to use a loupe to ensure the defect has been transferred entirely to the burr and is not longer in the cutting edge.

If you are careful to focus the abrasive effect of the stones on the extreme cutting edge instead of the rear of the bevel, the burr created before moving onto the medium grit stones should be barely detectable. Once again, except in the case of removing large chips or blade damage, creating a big burr is not only a waste of time, stones and steel, but if the large burr is torn off during sharpening, it will leave behind a tragic amount of damage that must be repaired by once again abrading the edge and raising a new burr. Don’t start chasing that tail.

Best to create just enough of a burr to confirm that damage has been removed and then encourage it to evaporate.

Don’t forget to check the angle of the bevel with your hand-dandy bevel gauge. See the section on Pixie Predation Prevention & Pacification in Part 11 of this series.

After the burr is in good shape, then polish the bevel on the medium and then fine stones. The burr will be polished away evaporating without special effort.

Finally, polish the ura side of the blade on the finest stone you intend to use. Feel the burr with your fingerprints and check it with your fingernail. Then polish the bevel on the fine stone. Repeat this front and back polishing process until the burr is polished away entirely.

Assuming the ura is already polished on your finest finishing stone, you shouldn’t need to touch the blade’s ura again on any stone until the final finishing stone.

Transitioning From One Stone to the Next

Recall that the purpose of each stone used after the roughest stone in the series is simply to replace the deeper scratches left by the preceding stone with finer scratches. In fact, there is nothing to be gained and much to lose by moving onto a finer stone before all the scratches from the previous stone have been replaced, so please check that all the scratches from the previous stone have been polished out before moving to the next.

This is not always easy to confirm without magnification, so to make it easier and surer, I suggest you skew the blade’s bevel on the stone for the last 3 or 4 strokes to make new diagonal scratch marks at an angle different from those produced previously. 

These skewed scratches will be at a different angle than those produced by the next stone, of course, and will be easy to differentiate from the new scratches with the nekid eye. When the next finest stone removes them entirely, you will know you have probably spent enough time on that stone, and can go to the next. But don’t forget to skew the blade again before going to the next stone.

Of course, there is no need to skew the blade on the final finishing stone.

Summary

We have discussed three important sharpening techniques in this article which you must master if you have not already:

  1. Raise a burr by abrading the blade’s bevel on your rough stones using your skillful technique;
  2. Test the burr for size and completeness using your fingertip ridges, and for defects using your fingernails. If the burr is incomplete or has detectable defects, continue to work the blade on the rough stones on the bevel side only until the burr is good.
  3. Skew the blade during the last 3~4 strokes on each stone (except the final finishing stone, of course) to create diagonal lines. When all those diagonal lines are polished off by the succeeding stone, you will know it is probably OK to move onto the next finest stone in the series.

You now have powerful tools at your disposal that can sense the state of a steel blade as thin as the edge of nothing, and without using your eyes, tools youv’e always had and which didn’t cost you anything. How’s that for value? (ツ)

Be forewarned, however, that if you use these techniques you may be forced to choose between a glamorous career as an international professional fingernail model or the quiet life of an expert woodworker. What to do, what to do…..

In the next and final post in this series we will use all the aspects of the sharpening process discussed previously to sharpen a blade step-by-step. Be there or be square.

YMHOS

The University of Tokyo’s Yasudo Kodo building hidden by Autumn Ginko leaves.

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may my eyebrows grow 10 inches everyday.


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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 it’s poor abused 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 at all. And don’t forget the time you spent 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.

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 Gentle Reader once again that the purpose of this blog is not to provide entertainment, sell stuff, troll for clicks or roll subscribers into Google Analytics’ Pit of Hell, 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 click the see the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may my face fall off.

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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

Beloved Customer has of course 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 sharpening 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. BTW, this is not a kindly suggestion but a commandment.

Second, it is human tendency to place uneven pressure on a skewed blade, with the natural result that the blade wears unevenly. Think about it now.

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, especially in the case of kiwaganna and other skewed-blade planes, causing self-doubt and mental anguish (aka “going bananas”). But if you are aware this can happen, and pay attention, you can easily compensate for it without months of expensive psychoanalysis or medicinal lithium. 

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. Your humble servant confesses that his 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. And there’s always lithium.

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 perfect, of course, as did Clint Eastwood.

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may my food turn to ashes in my mouth (a very ancient curse indeed).

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