Sharpening Part 15 – The Most Important Stone

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

Gatekeeper, Emerald City

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

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

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

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

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

Motivations

The Great and Powerful Oz has spoken!

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

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

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

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

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

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

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

Disclaimer

Here it is in red letters.

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

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

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

I have never done a product review.

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

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

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

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

Goals, Objectives and Priorities

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

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

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

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

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

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

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

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

The Goldilocks Set

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

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

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

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

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

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

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

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

Which Brand of Synthetic Stone?

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

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

The Most Important Stone

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

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

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

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

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

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

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

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

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

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

YMHOS

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The Marketing Department

Links to Other Posts in the “Sharpening” Series

Sharpening Japanese Woodworking Tools Part 1

Sharpening Part 2 – The Journey

Sharpening Part 3 – Philosophy

Sharpening Part 4 – ‘Nando and the Sword Sharpener

Sharpening Part 5 – The Sharp Edge

Sharpening Part 6 – The Mystery of Steel

Sharpening Part 7 – The Alchemy of Hard Steel 鋼

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

Sharpening Part 10 – The Ura 浦

Sharpening Part 11 – Supernatural Bevel Angles

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

Sharpening Part 13 – Nitty Gritty

Sharpening Part 14 – Natural Sharpening Stones

Sharpening Part 15 – The Most Important Stone

Sharpening Part 16 – Pixie Dust

Sharpening Part 17 – Gear

Sharpening Part 18 – The Nagura Stone

Sharpening Part 19 – Maintaining Sharpening Stones

Sharpening Part 20 – Flattening and Polishing the Ura

Sharpening Part 21 – The Bulging Bevel

Sharpening Part 22 – The Double-bevel Blues

Sharpening Part 23 – Stance & Grip

Sharpening Part 24 – Sharpening Direction

Sharpening Part 25 – Short Strokes

Sharpening Part 26 – The Taming of the Skew

Sharpening Part 27 – The Entire Face

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).

11 thoughts on “Sharpening Part 15 – The Most Important Stone

  1. Thank you sincerely for this post. I am so exhausted by the sharpening homework I’ve assigned myself. Pain being the best medicine, it’s taken me quite some time (and a case of contact dermatitis) to learn the above lessons. If it’s not right on the coarse stone/electroplated nickel whatever – it’s not right.

    The problem with the blind leading the blind, over the internet no less, is they can’t see any of the people they’re talking to. Who are trying, and failing (though I suppose in this case a failure might be worth quite a bit, depending on the cost of the solution).

    Thank you for your service. You are an invaluable member of the influencer community no doubt ;0. With so much learning still to do, it’s amazing the results and serenity that unlearning can often yield.

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    1. Mike, Thank you for your kind words and for sharing your wise observations. The contents of this post, while not sexy, are the foundation to developing professional-level sharpening skills. I’m glad you have already learned them. Like you, I struggled for a long time before the advent of the confusing, orc-infested snakepit that is the internet to learn them. Looking back, I think the lack of the internet was beneficial because I went looking for guidance from real professional craftsmen instead of wasting time wandering long in the dark and murky digital wilderness. It’s my hope that other readers will gain enough from this blog to spare themselves the same trouble, expense and dermatitis. Cheers!

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  2. Depending on how much work the edge needs I start at the Atoma 600 or 1200. Most of the time the 1200 is more than enough. Gotta love the speed and efficiency of diamonds. After the Atomas I switch to natural stones. First it’s a large slab of Coticule that I use with a thick slurry that puts it in the 2-4k range and easily erases the scratches from the Atoma 1200. Then I dilute the slurry for finer sharpening and I finish on only water for a fine edge. This is where I stop with my atsunomis as there really is no point in going to a higher grit with these. After the Coticule I switch to an Ohira suita for my oire and usunomis. I flatten all my stones with a 400 grit diamond plate from Kensyo (before the Kensyo I used an Atoma 400 for this). A diamond plate is a faster and more efficient way to flatten stones than the antiquated two stone method.

    I know you will probably say the stone will be contaminated with diamonds but it won’t. I’ve never had an Atoma or my Kensyo shed diamonds flattening stones.

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  3. One quibble and one question. The quibble is about there not being a difference between synthetic stones. I started using King stones decades ago and while it was a lot of work I could get a reasonable edge. Last year I switched to Sigma II stones and holy moly what a difference! So much faster! I also just got some Pride Abrasives stones (made in the US of A) and they are basically like the Sigma stones. Much faster than the Kings. So based on my limited experience I would say that speed of cut can vary a lot among at least these synthetics. Has that not been your experience?

    Now the question: in your opinion is it safe to keep water stones, either synthetic or natural, in water or should they be dried after use? Let’s assume that I’ll be using them 5 days per week. Should I take them out of the water at the end of the day and dunk them the next? Or just leave them submerged? I’ve read that the answer is, 1) don’t do it, 2) go ahead it’s fine, 3) it depends (on things that are never specified).

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    1. Gary, thanks for your comment. Most welcome. I agree that King Stones are probably not the best anymore. I don’t use them except for some old Gold Stones I have laying around. But I don’t want to comment on one brand versus another. Regarding storing synthetic sharpening stones in water long-term, other than the 6,000 and finer grit ones, I keep mine in a bucket of water 365. I cover the bucket with a piece of plastic to slow evaporation and add Simple Green industrial cleaner/disinfectant to keep algae and mosquitoes from growing. No degradation. Of course, I don’t let them freeze. I think many soaking/drying cycles tend to make them harder over time, at least that’s my experience with the stones I use. Some varieties of Shapton Stones are famous for melting if kept wet too long, and soaking can be deadly to many varieties of natural stones. But in my experience, for rough and medium synthetic stones of any brand, constant soaking should fine unless the manufacturer specifies otherwise. Stan

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  4. Magnesia based stones like the Naniwa Chosera and Shapton Pro can and will melt or crack when you soak them 24/7 due to the binder (magnesia) leaching out. Ask me how I know 😦

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  5. I had a Shapton Pro 1000 and 5000 that were quite soft after I stored them in water for a month. I was curious to what would happen after 3 months so I left them in the water. When I took them out I was able to easily break both in two pieces. Shapton also tells you not to soak their stones for more than 30 minutes but I didn’t know that at the time. My next stone was a Naniwa Chosera 3000, another magnesia based stone, and I was told storing it in water was fine. It wasn’t though because it cracked after 2 months. After going through 3 stones I learned that magnesia based stones will leach their binder into the water.

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    1. Henk, Thanks for the insight. Unfortunate result. Right now I have 4 Bester (Imanishi) stones soaking in a bucket. I have changed the water many times, but one or two of those 1,000 and 2,000 grit stones have been soaking continuously for over two years. No problems. I have done the same with King stones too with no problems. Friends have told me stories similar to yours about Shapton stones, but no one ever mentioned magnesium being the cause. Deiter Schmid (https://www.fine-tools.com/naniwa-chosera.html) mentions the same problem with Chosera stones, consistent with what you wrote. I did not continuously soak my Shapton stones so perhaps that is why they held up OK, but I don’t think they are a good value and haven’t bought anymore. What has been your experience with Sigma? When I find a stone that works well for me, I buy in volume. I bought 2 cases of the Imanishi stones at a time discount 12~13 years or so ago because I knew I would use them up. Imanishi’s products are not fancy but do a good job for me and I got a good discount. I still have 2 or 3 of each grit left, so it will be a while before I need to resupply. I did the same with my 6,000 grit finishing stones. They are a brand called “Pony” that a carpenter friend recommended. I have never seen them outside of Japan. They’re a little hard, but with a Tsushima Nagura startup dressing they do a satisfactory job. I bought just a single case and only have one fresh stone left. I understand the maker of Pony brand is no longer in business, so I will probably need to find a replacement next year, I suppose. Suggestions? Perhaps the Coticule will work as well or better?

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  6. Sigma makes excellent stones. The Ceramic line that is, not the Select II line. The Sigma Power ceramic 6k (aka jinzo renge suita) is the best 6k stone on the market in my humble opinion. It’s hard, dense, fast, dish resistant and has excellent feedback. The Sigma ceramic 1000 is terrific as well but it comes in two forms, hard and soft. Be sure to get the hard one. The ceramic 2k is more of the same. You really can’t go wrong with any of Sigma’s ceramic stones. I don’t like the Select II line as much. These were developed specifically for very hard steels like HSS and they will mud up a lot with softer steels like the jigane. Not my cup of tea.

    The Coticule will do a great job as well. Even better in my opinion because it creates a very robust edge. Just make sure to focus most of the pressure on the hagane. You’ll see what I mean.

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