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 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 our Beloved Customers 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 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 want to create a barely-detectable, tiny and clean burr as soon in the sharpening process as possible. My advice is to do it on the 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 look at how to test it next.

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 a small burr, 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 off without special effort.

Assuming the ura is already polished on your finest finishing stone, you shouldn’t need to touch the blade’s ura 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. Therefore, it is important to 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 some powerful tools to use when sharpening your excellent tools, and none of them cost you a nickel. 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

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 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 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 16 – Pixie Dust

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

Carl Sandburg
Related image

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.

Related image

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

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The Marketing Department

Links to Other Posts in the “Sharpening” Series

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

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

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

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

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, profitably “misplace” your information, or do any other monkeyshines with it.

Sharpening Part 11 – Supernatural Bevel Angles

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Pixie, kobold, elf, and sprite, All are on their rounds tonight; In the wan moon’s silver ray, Thrives their helter-skelter play.

Joel Benton

Iron Pixies

Gentle Reader, have you ever placed a tool down, only to later discover it has vanished into thin air? Do your tools ever become unexplainably dull or corroded within what seems like just a few days after cleaning and sharpening them? If so, you may have an Iron Pixie infestation without realizing it. 

Respected fairyologists theorize that, unlike their timid brethren frolicking in forests, or their blingy cousins in Hollywood, New York, and Washington DC who delight in tricking the mass media, film industry and corrupt politicians into constantly making greedy, immoral, hypocritical fools of themselves, Iron Pixies (genus Fatum Ferrum), do not fear iron or iron alloys. Indeed, besides pilfering and concealing tools that contain iron, they love nothing more than to use their corrosive powers to return this metal to its natural state through the thermodynamic chemical process known as “rubeum, et conversus abibo” (turn red and go away).

These piratical pixies become especially joyful if the owner of the snatched tool is unable to find it after much frantic searching, and is eventually forced to buy a replacement. Only when they see the replacement tool will the pernicious pixies permit the owner to locate the pilfered tool, usually rusty and chipped.

We’ll come back to the supernatural aspects of woodworking tools, but first let’s examine some more mundane details about sharpening blades, and a few things that typically go wrong with them.

The Ideal Bevel Angle

There is such a thing as an “ideal bevel angle” for each blade in each cutting situation, one that cuts the wood quickly, cleanly, with minimum force expenditure and that keeps the blade effectively sharp for the maximum amount of cutting possible, but determining this angle is not an easy calculation since it is difficult and expensive to actually observe what is happening at the cutting edge from a shaving’s-eye-view.

For example, a steep  60° bevel angle on a chisel will support the cutting edge thoroughly and will be durable, but it will pound the wood more than cut it wasting time and energy and damaging the wood unnecessarily. On the other hand, a 15° angle will cut well, but is likely to chip and dull quickly. A balance is necessary.

This balance will depend on many factors including hardness and abrasiveness of the wood you are cutting at any time (e.g. Sugar Pine versus Ipe), the quality and nature of your chisel blade, the type of cut you are making (low-pressure surface paring versus high-pressure deep mortises), and the care you take to protect the cutting edge. Yes, technique matters.

Determining the ideal bevel angle is ultimately a trial and error process the diligent craftsman will unconsciously perform until it is second nature, but the following are some general guidelines to get you started.

Most Japanese woodworking tools, including plane blades and striking chisels (oirenomi, atsunomi, tatakinomi, mukomachinomi) perform well in most construction and furniture woods with the standard 27.5°~30° bevel angle. This is a good compromise, acute enough to cut most wood efficiently without too much friction, while still providing adequate support to the thin cutting edge to avoid chipping. 

But like any rule, there are exceptions. For example, 35° is often a superior bevel angle for chisels when quickly cutting mortises in harder woods or planes shaving tropical hardwoods.

When cutting very soft woods, such as Paulownia, similar to balsa wood, a 22~24° bevel angle may work best. 

Paring chisels (tsukinomi), when used properly, are subject to less violent forces than striking chisels, and can handle a 24° bevel angle. But for most woods, a professional-grade Japanese plane or chisel blade will likely experience chipping if the angle is much less. 

There are many variables and potential solutions one might consider, but as a general rule, I recommend starting your experiment with a 27.5~30° bevel angle for plane and chisel blades. 

If you find that your blade chips or dulls quicker than you think it should, increase the angle gradually until it calms down. This can result in a double-bevel blade, one difficult to sharpen freehand. In this case, I fully support using a honing jig, at least until you achieve a flat bevel wide enough and stable enough to sharpen freehand. But don’t handicap yourself by relying solely on honing jigs because they can become like training wheels on a bicycle: slow and childish.

Mercurial Bevel Migration

There is a strange, almost supernatural phenomenon many woodworkers experience, the first evidence of which is a plane or chisel blade that previously held a sharp edge a long time suddenly and unexplainably beginning to dull or roll or chip sooner than before. Even professionals with many years of experience occasionally see their tools exhibit this nasty behavior. 

Some craftsmen faced with this dilemma begin to question their sanity. They may ask themselves: “Has heaven turned its face against me? How do I rid myself of this curse? Do I need to see a shrink?” Other craftsmen, more aware of the dangers of pernicious pixies, draw strange hex symbols on their walls or inlay brass circles and pentagrams into their floors to exorcise them from their workshop. Indeed, this practice has a long history in Europe and America.

Related image

Unfortunately, more than one blacksmith has been falsely accused of poor workmanship when the fault actually lay with the tool’s owner unwittingly allowing Iron Pixies to run amok. If this happens to your tools, please use the methods described below to purge any pestilent pixies in the area.

You would be wise to consider all possible causes of Mercurial Bevel Migration (MBM), including those unrelated to any infernal fiends that may or may not be skulking in your lumber stacks. 

But if not pesky pixies, what else could cause this maniacal metallurgical malfeasance?  Never fear, Gentle Reader, there is another possible explanation, one that can be resolved without paying for years of expensive psychotherapy and mind-altering drugs, or placing small bowls of blood and milk around your workshop, or enduring the pain of tattoo needles, or paying for stinky ceremonies involving burning sage and spirit drums.

The more likely cause is simply that it’s human nature when sharpening chisels and Japanese blades with their laminated, top-heavy construction to apply more pressure to the bevel’s rearward half (farthest from the cutting edge) abrading the softer jigane body more than the harder hagane cutting layer. Eventually, as the soft jigane wears away, the bevel angle will decrease to the point where the cutting edge will lose support and become fragile.

Once you are aware of this tendency and take preventative measures (and assuming you don’t have an iron pixie infestation), all should be well.

Next let’s examine some measures to get rid of both this bad habit and trixy pixies.

Pixie Predation Prevention & Pacification

If you suspect the presence of iron pixies, you should perform a Pixie Detection test. A reliable method is described in the next section below.

In any case, to avoid pixie infestation, you should create a workshop environment unfriendly to pixies. The following is an partial list of measures I have found to be effective.

Image result for brass bench dog
Brass bench dogs are an effective pixie repellent
  1. Cleanliness: Clean bench surfaces and sweep the floors daily. Periodically vacuum and wet-mop workshop floors twice a year during the winter and summer solstices (approximately June 21 and December 21);
  2. Add more lighting: Iron Pixies fear light because it reveals them to their enemies;
  3. Keep a pair of boots near the door into the workshop: Pixies are deathly afraid of boots, especially when they contain the feet of sharp-eyed human children, but just the sight of boots will prevent them from entering a space;
  4. Keep brass benchdogs in your workshop. Expert fairyologists insist, and I agree, that having a brass bench dog (remember, Iron Pixies do not fear iron or steel or the IRS) or two close by will banish Iron Pixies to the workshop’s dark recesses and keep their nasty claws away from tools. The deterrent effect of bench cats is unclear, but if you decide to rely on one, be sure it bothers to stay awake;
  5. Welcome spiders: Although this may seem to contradict No. 1 above, Iron Pixies fear spiders, especially daddy longlegs, who tangle them in their webs.
  6. Make regular offerings to the gods of handsaws. More on this subject in future posts.
Richard Kell bevel gauge
A compact and effective brass bevel angle gauge by Richard Kell

A more mundane but sure way to prevent MBM is to make or buy a bevel angle gauge and regularly use it to check your bevels during sharpening. Aluminum, stainless steel or even plastic gauges will work of course, but brass or bronze are more effectual at purging perfidious predatory pixies because copper is toxic and zinc causes pixies indigestion. Be sure to store it close to your valuable steel tools to help repel the maniacal monsters.

Here’s the important thing: once you have this tool on hand, use it to check each blade before, during and after sharpening to ensure you are maintaining the correct bevel angle instead of allowing it to decrease incrementally over repeated sharpening sessions. Make this a firm habit. More on this important subject in future posts.

Remember to measure the bevel angle at the blade’s far right or left edges because the hollow-ground ura of Japanese blades makes it difficult to correctly measure the angle if you check it elsewhere.

Pixie Detection Methods

A serious pixie infestation in a toolchest located in a clothing-optional workshop. Notice the absence of bench dogs, bevel angle gauges and boots in this image. An invitation to disaster!

Iron Pixies are secretive creatures most people never see, but if you suspect you have an infestation, a detection test is called for.

While there are many proven methods to test for pixie infestation, the least expensive non-toxic iron pixie detection test is to sharpen a plane blade, and while doing so, attempt to “stick it” on the stone as in the photo below. This phenomenon is evidence the stone and the blade are in such perfect contact that the suction between the blade, water and mud on the stone’s surface strong is enough to support the weight of the blade.

No, this is not a trick photo with concealed supports, superglue, or photoshop enhancements. The blade is “stuck” to the wet stone’s surface. This is a rite of passage those who wish to become proficient in sharpening must accomplish, iron pixies or no. Not recommended for potato chip-thin Bailey-style plane blades.

If you are unable to accomplish this marvelous feat even after many attempts, you can be assured of the presence of peevish pixies nearby. In that case, use the preventative measures listed in the section above. You should also flatten your sharpening stones (especially the rough and medium grit stones) and make sure your blade’s bevel is perfectly flat. Bulging bevels are the pernicious pixie’s playground. (Aha! Iambic pentameter!)

Fair warning: If you stubbornly persist in your efforts to stick a plane blade before purging the area of pixies, they may go berserk to prevent this sublime event from occurring. If that happens, Katy bar the door!

Infernal Pixies! You Shall Not Pass!!

In the next stage of our adventure, we will examine some of the health ailments blades commonly suffer.  High cholesterol in chisels? Planes with pneumonia? Or just toolish hypochondria? Stay tuned to find out more.

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

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