Home » Paul Sellers’ Blog » Diamonds Are Forever – Or At Least Here to Stay

Diamonds Are Forever – Or At Least Here to Stay

There is always the challenge of changing someone’s made up mind once the mind is indeed made up or someone has already perhaps invested time and money into something or, even more, taken offence. It’s natural to defend a stance we already agree with, after all. We all do it to some greater or less degree I think. But being close-minded means much effort is often wasted.

By now you should have realised that abrasive is available to us in many different forms and that both abrasive and steel wears away.

The Encyclopaedia Britannica describes abrasive thus:

Abrasive, sharp, hard material used to wear away the surface of softer, less resistant materials. Included within the term are both natural and synthetic substances, ranging from the relatively soft particles used in household cleansers and jeweller’s polish to the hardest known material, the diamond. Abrasives are indispensable to the manufacture of nearly every product made today.

Of course there are then pages describing the substance of abrasive we don’t need at the bench, but what we need to know is that about 95% percent of the abrasives we use in woodworking and sharpening is man made using naturally occurring materials mostly mined and then fired into the bricks we call whetstones or sharpening stones. Some of these stones work best with water and some with oil. Natural stones are generally mined or quarried and then cut to size and graded according to quality, hardness and size. Natural stones were the standard means of sharpening for centuries. Many natural occurrences affect the quality of natural stones and this leads to higher levels of waste material that can then be used to make man-made stones and so minimise waste. Man-made stones have the least waste of all.

What happens at the purchase point results from the decision you make in choosing stones or a sharpening method or system. In fairness to catalog suppliers, the range is massive and the demand great. I would not like the job of categorising and choosing the offering although it is dead simple for me; in the name of the old Bond movie I think, “Diamonds are forever.” I think I have already said this but all abrasive stones cut steel. Because powdered abrasive doesn’t remain in position but as loose particles gets pushed around, most abrasives are formed from particulate into hard blocks and wheels. Some sharpening stones rely on a slurry from the fractured surfaces to further abrade and polish surfaces of steel.P1010386

Sharpening stones

The width of most stones and plates used by woodworkers is between 25-30mm thick by 50-75mm wide and 200-250mm long, but larger stones and plates are made and used. I use 75mm by 200mm (3” by 8”) diamond plates. A favourite addition of mine is a 200mm x 200mm coarse diamond plate for restoration of bevels. 

Most bench plane irons are between 50mm and 65mm wide. Up until the recent guru workshops, people held the plane iron in the right or dominant hand so that the iron and hand align comfortably in the arm and with the body squared to the end of the oilstone applied pressure from the greatest advantage point for applying adequate pressure.

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Stones today might still be generally categorised under the generic term whetstone but it’s an older term, which simply means sharpening stone. Oilstones are whetstones as are waterstones as are diamond plates. These stones are made up of solid particulate graded according to coarseness except for the diamond plates which are steel based and surface coated with diamond particles in different grades. Diamonds are the hardest of all substances and are the most wear resistant. All other stones start out flat and wear down throughout the sharpening process. This wear forms a curved or hollowed surface. The modern trend is to continually flatten the whole surface of stones and I believe that this is somewhat valid if indeed the stone is hollowing and not just curving. In a previous post I told you that it’s simply a method to combine the use of oval motions with overhanging the long edges of the stones to keep the stones flat across the narrower width throughout sharpening. This is to even out the wear, but this of course is only practical with wider blades such as bench plane irons and wider chisels 1” and up. The long curve, as distinct from hollowed or dished, doesn’t need to be flattened really, but the reason for flattening is mostly  the initial ease. You must then figure this into the equation because constant flattening then negates the initial ease.

Do all stones need to be dead flat?

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A dished stone is very handy to have around
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Flat and straight and curved and convex – I use both

There can be no doubt at all that all stones were worn to curved and/or hollowed surfaces throughout the centuries and millennia. It was not because they couldn’t flatten stones but because for general use there  was little need to. It also meant that they knew the necessity to manipulate the steel blades they were honing or grinding to keep stones more evenly shaped or shaped how they wanted them shaping — how they ‘liked’ them. When I used oilstones I did that too, mostly because I liked to stop my stones from hollowing. I would dare to go much further than this and say that in some cases, for curved irons, gouges and such, they relied on curved surfaces customised by their individuality in the same way craftsmen and women through the millennia developed shapes to metals and clays and glass and fabrics by eye and arm movements and could replicate exact shapes over and over with barely any discernible differences. Curved surfaces along the length of a stone still facilitates a good cutting edge without compromise in any way at all, but working with narrower tools such as 1/4”, 3/8” chisels, plough plane irons and such caused gouging and hollows to the stones that they couldn’t just let go because these causes ever-deepening hollows that, left uncorrected, renders a stone unusable for wider plane irons.P1010397 Now let’s look at hollowed surfaces for a just a minute. I remember one time using a hollowed stone to sharpen my edge on a number 4 1/2 plane iron. After two strokes the man who’s stone I borrowed told me to stop as I was ruining his stone. I was holding the iron at the wrong angle or a different angle from the one he would usually use. When he honed his iron the sound was smooth but when I honed it was more a coarse grating sound. He showed me the angle he honed at, which was more elongated along the length of the stone. This meant that the cutting edge came out with his preferred gentle camber along the edge of the cutting iron. I was 16 years old. I understood then that not all stones needed to be flat. You see, for me, the question is who is it in this generation that demands flatness to every sharpening stone? It wasn’t heresy to have curved stones then and it isn’t today. P1010403A hollowed stone may vary in depth but, by adjusting the angle of presentation longitudinally and laterally, you can create diversely varied curves to the cutting edges of tools according to task. Many craftsmen used a cambered iron in those days. It was more common than we think. That said, you can create cambered irons on flat stones too. To do that I might use a figure of eight method, but I can simply roll the iron too. Scrub planes are bench planes that employ the deepest curves. The problem with hollowed stones is the effect they have on the bevel of the tools such as chisels. If the stone is hollowed then the bevel is convex in both directions and the chisel edge of say a 1” chisel or a plane iron cannot be straight. In most chisel work we rely on the edges being as close to straight as possible. That means flat becomes generally a necessity. Flipping the chisels over and using the hollowed or even curved stone for the flat face is obviously devastating because even after just a few strokes it’s a lot of work to reflatten the face to remove the now curved corners. 

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Hollowed stone
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Flat across but curved along
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Flat faces curve corners on hollowed stones – not good!

Many people have restructured their thought processes. At shows about five years ago salespeople and gurus were set up with waterstones, flattening stones and baths of dirty water. No one would have set up with oilstones at that time because even though they worked fine and were clean and easy to use, they had become old fashioned and out dated. Today it’s changed all the more and the same people once selling waterstones are now set up selling diamond plates of different types because, I think, mostly people saw that flattening waterstones was messy looking, dirty wet, can be expensive and time consuming and oilstones are, well, old fashioned. Other stones like ceramic stones are options too and my choice outside of diamond plates might well be ceramic stones but they are not so easy to find. That said, my concern is getting people to the work at as low a cost as possible and especially for those who just don’t have the money for expensive stones and plates. The lowest cost start up is using stones. They cut steel effectively and they are not that expensive generally but you have to work at stopping them from dishing and especially is this so with narrow chisels and plane irons. It’s not so much the wider plane irons that cause the dishing and uneven wear issues although they do too, it’s the narrow blades that cut deeply and unevenly.

Concluding preference

Personally I concluded long ago that flat diamond plates are the simplest and most effective long term solution to almost all of my sharpening edge tools. Long term they prove the cheapest too. I prefer non mechanical methods because in general it’s faster and more effective and very convenient. P1010373Every chisel and plane iron in the New Legacy woodworking school is still sharpened using diamond plates only and they (both tool and plates) do last and last well. I value what our forebears developed using stones alone and want to respect that their work was exemplary using dished stones and often stones unequal in quality to their ambitions. P1010371Stone makers have given us a vast array of water stones to work with and solutions to flatness and we can indeed keep one side curved and the other flat to reduce sharpening time or have separate stones for different tasks and tools. It’s still confusing to thumb through a tool catalog be that paper copy or online. Too much info’ creates a dearth of what it takes to understand it and that’s attention.  Not many of us working people have the time to ‘pay‘ attention. I’m not sure if that’s going to change.

15 comments

  1. Gary Blair says:

    Hello Paul,
    As I was telling Eddy Flynn in a related post, I started out a couple of years ago sharpening with an old hollowed oil stone and felt I was completely “behind the times” because that was all I had or could afford at the time. I then progressed (or so I believed) to water stones.. Though I was satisfied with the results, I believed what I had heard and ended up spending more time flattening the stones (and cleaning up the wet mess) than I did actually sharpening! Then, after discovering your lessons, I saved up and purchased the three EZE Lap diamond plates, made a holder, made a strop on a board charged with chromium oxide, and haven’t looked back since…. It now amazes me how little time I spend sharpening! That said, though I love my diamond plates, if I had to regress, it would be to my Grandad’s old hollowed oil stone. Best wishes to you and your family during Christmas.
    Gary Blair
    Lander, Wyoming

  2. Craig says:

    EZE Lap diamond plates are great but sometimes I wonder, we are so hell bent on this site in keeping traditional methods by the using hand tools, but when it comes to sharpening our tools we marvel and praise at the modern product, to which is to me is rather hypocritical of us all, myself included. For hundreds of years craftsmen have been using oil and water stones, and they produce exceptional work, sharpening their tools were a way of life and in their work pattern. To us “modern” woodworkers(not Mr Sellers) it’s a daunting task so we look for the quickest way out, I once spoke to an old woodworker about introducing him to EZE lap’s he told me that when he sharpened his tools, he had a several stones (oil) for certain tasks for his tools, he told me that he could feel for each chisel, plane iron for what he required the individual tool to do for him to which diamond plates could never do for him as they were to flat for him, having read your blogs Paul I see now what he was talking about.

    • I think your’e right and the point should always be not to be too automatically dismissive of the past as not having what we smarts have got today because we should always be conscious of one reality; very, very few woodworkers match the standards of what was once common to almost every woodworking craftsman of old who had nothing of what we have access to today. I see beautiful cursive script in notebooks and signatures underneath pieces too. I see math formulas for elliptical roof voids and roofs spanning many yards hanging from king posts that most of us might dream of working on nowadays documented in plan drawers.
      We are indeed adapters. We take our bodies and minds and apply them to keyboards and achieve results we need not be ashamed of. When we go through three decades and persuade everyone that sharpening stones must always be dead flat we should at least have the integrity to ask who said that or why. Especially if we look at a £10,000,000 violin and we can’t yet replicate the varnish on it or even the particulate grit size used on it. I love the idea that new woodworkers will discover new things we never knew of and hope they will always acknowledge the great men of the past who never sought or even thought to signed their work but worked with honesty and integrity.

  3. David Devereux says:

    Paul, a question I posed in a recent post but you may have missed. Are you aware of what is taught in schools these days as that is where it all ought to start?

    • It is hard to keep up with what’s happening in schools save to say that the schools teach to national curriculum via Design and Technology (D&T) resistant materials classes but this is less and less hands on as schools use technology assistants to actually set up and use machines for most of the work in place of the students. School teachers are usually not well prepared or equipped to teach students and of course D&T is only compulsory through 14 years of age so the age when they can really do something isn’t even reached really.

  4. Juryaan Mulder says:

    Paul,do you think japanese chisels can also be sharpened the way you sharpen your chisels?
    Most people on the internet say they are not ment to be sharpened on daimond stones and certainly not with a round bevel .
    What is your opinion on this?

  5. Robert Wood says:

    Hello Mr. Paul Sellers,
    Thank you for the way you have shared your knowledge and experience.
    I have become an admirer of you and your philosophy of woodwork, etc.

    I was looking at the reviews of the EZE-LAP diamond plates and I am concerned with all the reports of these plates being warped.
    Have you heard of these same reports of these diamond stones being warped and do you have a comment or alternative on a good dlamond flat stone?

    Thank you,

    Robert Wood

    • Never have I had one warped or seen one warped elsewhere. If I got one warped I would just have it replaced but that’s never happened so not a problem for me. There will always be competition and preferences between makers and users and of course I could go on because I have seen plates recommended by others putting their name to a plate or selling plates at shows who never tell you that the worse problem of electroplating separating happens constantly or some other such issues whereby sections of diamonds are sloughed off but none of these things have happened for me with EZE-Lap and we are hard users of them.

      • Robert Wood says:

        Thank you very much, sir.
        FYI, I first heard about you on a favorite youtube channel, “Wranglerstar”.
        I have also bought your Artisan coursr 1 and 2 book because of his recommendation.

  6. Lewis Gold says:

    How do you secure the three diamond plates to the wooden base. It appears that they are secured by some fashion that allows you to hang up the board without the plates falling off the board.

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