Questions on sharpening stones

Dear Mr. Sellers

I am about to work my way through your course, I want to start with sharpening. I recently discovered that my new chisels, although of good quality, needed to be lapped. I turned to my Norton water stones, only to discovered that they needed to be flattened. I then turned to my Norton flattening stone only to discover that it was crowned (not dished) and needed to be flattened. So now I need to buy a diamond stone to flatten the flattening stone to flatten the water stones to flatten the chisel! I therefore appreciate your logic of eliminating the ‘middle men’ and flattening the chisel directly on the diamond stone.

 However, before I purchase the diamond stones, I have a question concerning the gradation of the stones which I hope you will be kind enough to answer. 

 I currently use three water stones 1000, 4000 and 8000 grits to grind, hone and polish. When looking at what DMT (the maker of the stones available from Lee Valley) offers, a trio of 600, 1200 and 8000 seemed appropriate though I wondered about the jump from 1200 to 8000.

 You use 250, then 800 and 1200 grit stones to grind and hone, followed by 15000 grit stropping to polish. DMT recommends 325, 600 and 8000 stone followed by polishing with 1 micron paste. Your gradation (and DMT’s) is quite different from what I expected.  Can you explain the reason for your choice and whether the medium is a critical issue. In other words, if you were to use water stones, would choose a different mix.

I look forward to your response and getting your course off to a sharp start!

 Bill

Montreal CANADA

Hello Bill,

Firstly, I have shortened your letter just a little to reduce the lead in for the readers and to keep your name private. Here we go:

Para 1:

Uneven surfaces on sharpening stones is most common and in the ones I have tested, high end ones included, the problem is common to almost all stones. This is an extreme and rare exception in better quality diamond plates. Cheap sharpening plates are rarely flat and all other stones never stay flat because that is impossible. Especially is this so with   self fracturing water stones, which is the main advantage of good diamond plates. That being the case I stay with diamonds alone because they never let me down. I have noticed of late a hybridizing of abrasives. I think that this is often more silly than practical. I am not sure why people complicate things so. perhaps it’s to supposedly create their ”own methods.” I find that it’s this that confuses the whole issue of sharpening and prolongs what should be short, quick, simple and effective. Better instead to simplify rather than merely make a name for ourselves.

A few years ago, for about three decades, all the guru woodworking writers were advocating Japanese water stones. Everyone went in that direction and began rejecting other types of natural and man-made stones and started buying stones that, well, wore out. Great stuff for catalogue companies and salesmen who were also offering the same advice for some reason I assure you. Remember that many of our present day “experts” became gurus through slick sales talk and we have seen them go through the gamut of selling planes, selling techniques and selling sharpening stones or plates. Many of them have gone from selling water stones to selling diamond plates, diamond paste and tons of other stuff. One company, Trend, sells a bottle of diamond lapping fluid for an unbelievable £7.50 and states that WD40 is too thick and that doing so “results in your tool skating over the diamond surface.” This is not true and therefore in my book that makes it a lie I suppose. That said I don’t advocate WD40 because it is primarily composed of hydrocarbons. I generally find glass cleaner, not window cleaner, the kind we use for cars, the best treatment and instead of paying £7.50 per 100ml I can buy 500ml for under £1 from any Pound stretcher store and it works as well if not better. Watch out for the snake oil!!!

Para 3:

By now you will realize that I have no time left for water stones because of their intrinsic propensity to disintegrate and end up hollow. Using another stone to flatten it depends on that stone being flat. Though it may start out flat, it cannot stay flat, so we have a built in problem all around. Forget water stones and get diamonds. How did that song go? Diamonds are a man’s best friend.” It’s a good idea to progress rapidly to diamond plates and better quality ones such as EZE Lap or DMT.

When it comes to particle size as you rightly say I have used 250, 800 and 1,200. This in fact quite arbitrary really because the particulate fractures and becomes finer as you work the stones. What starts out as coarse 250 ends up being much finer the more I use it. Eventually I replace the coarse because of this. It would actually be hard to say what the particle size is on any stone once they have been used for a few weeks. So, instead of become overtly concerned about grit size I have found course fine and superfine from EZE Lap works well and has worked well for me for over a decade. Nothing more philosophical than that really. I will say that I find 8,000 grit a huge jump and would tend to stay with jumping with the buffing compound rather than diamonds. The finer the grit the greater the propensity to surface clog. You don’t get that with compound and a strop or wood.

Not scientific at all, but you see the results as I work. People have become overtly obsessed with sharpening to fine levels that are impractical for real woodworking in general. That’s fine if the intension is to sharpen and not work wood. Many such people lose sight of the fact the wood itself is abrasive and so what starts out at 15,000 or 20,000 becomes  reduced to a few hundred in the first few strokes anyway. That’s the edge that becomes long lasting, not 20,000.

53 comments on “Questions on sharpening stones

  1. Interesting stuff about gurus flogging waterstones and bandwagon jumping. I can’t imagine why the Japanese have wasted centuries using them….still, what would they know?
    BMG

    • bmg,

      it most likely has to do with the fact that diamond stones didn’t exist back then. nor did many of the other methods used today. plus, i don’t think this is “bandwagon” jumping. Like me for instance, I switched to diamond stones while everyone else was talking up water stones all the time, well before I even knew who Paul Sellers was, sorry Paul. I just got sick of flattening stones all the time and dealing with the water.
      the results are what really matters. I get better results quicker and easier with diamond stones than any others I have used. You are entitled to your opinions I guess, but they should be thought through with historical context. What if the Japanese had diamond stones 1000 years ago. I bet they would have switched themselves.

    • We’ve been using oil stones for centuries – so would the Japanese if only they knew!
      Re the OP above, if I were him I’d just get stuck in sharpening with whatever he’s got in the way of kit, and not to look to closely at “flatness” and other distractions. Not to bother with lapping either – a waste of time and effort.

    • We know why they use water stones. Its history and tradition. You cannot use a square edged stone to sharpen traditional Japanese weapons. I’ve asked and witnessed it. They use water stones because they can round the edges a bit. Woodworkers are not weapons sharpeners, but tradition has crossed over into carpentry. You can see videos on sharpening Japanese swords for museums. Its just a historical remnant; more cultural than anything.

  2. I switched to diamond stones a while back after using water stones for a long while. I will never switch back. Diamond stones and stropping makes sharpening quick and easy, best edges I have ever had in half the time, easy to clean up, and best of all, I get more actual work done, both at home and at work I use diamond stones. Really the best way to go.

  3. We were just talking about this on Thursday. I was told it might end up with a smoother cutting edge if I went to a 6000 grit water stone between my diamond stones and my strop. And, in fairness, I tried it on my 3/4″ chisel, and it came out to a perfect mirror finish. I then took my 7/8 chisel and worked it just a bit longer on 1200 and the strop. It came out comparable, but certainly not as clear a polish. Is this difference, so minute to the eye even under magnification, really going to make a practical difference?

    • I am sure that it is measurable and that it makes a difference with a first or second cut, but in the practice of every day the first and second strokes take that edge and so within a few strokes you are reduced to a lesser level before you can derive great benefit from it because no tool can actually retain that perfect edge. for anything but temporarily. Some tools hold it longer than others and that’s the whole point (or edge). The choice is yours really. You can buy a chisel that takes and keeps a keen edge for 50 bucks or 5. Some take a keen edge and some don’t. I just happened to discover that many cheaper chisels take and keep a keen edge and the edge is easy to get. The most expensive chisel I use in any of my videos so far have all cost less than $7-10 max. I also know that all too often I cannot tell the difference after but the very shortest time. For some highly specialised work such as carving a violin scroll I need this, for chopping a mortise and paring an oak tenon I usually don’t.

      • That’s what I figured honestly. I used both the 3/4 and 7/8 for both paring and chopping, and while I did notice a pronounced difference in functionality when I took a pinch longer on the 1200 stone and the strop (and I’m talking about 20 or so strokes on the 1200 and about 50 strokes on the strop rather than what you do in the videos), I noticed no difference in truth between the two chisels. And, FYI, I noticed no difference in the function of my $70 Narex’s and some of my co-workers chisels in the range of $200-$500. Wonderful!

  4. Hi Paul,

    Is there any maintenance you do on your diamond stones? I bought a couple of EZE Lap (the 6×2 ones) stones and I’m sure they’re losing their cutting ability, after only a few months of occasional use.

    I’ve cleaned them with washing up liquid and water which seems to help a little but I was wondering if there’s something else I should be doing to look after them properly.

    George.

    • Hello George,

      All I use is auto glass cleaner. My stones cut for dozens of students and often for years. All diamond stones lose their abrasive qualities and settled down to a consistent level. You don’t say what grit size your’s are so it’s hard to answer. EZE Lap has held up fine for me as have DMT.

      • Hi Paul,

        Is an auto glass cleaner like auto gym fast glass what you mean? I didn’t know the difference in windex window cleaner and an auto glass cleaner being from the US but looks like I can get auto gym products in Canada

        • Not really sure what the difference is between auto glass and glass cleaner but it is less frothy and works better.I have found that inexpensive glass cleaners equal the honing fluids I have experimented with at a fraction of the price with no downside at all so I hate to see people spending much for so little. I am sure there could be something to honing fluids but presentations to me have so far failed to impress me. I buy auto glass cleaner from Dollar and The Dollar Store chains when I am there. Autozone sells something that smells and looks the same for about $5 a large spray bottle and that works too. I suspect that they take out whatever froths and smells like house cleaning stuff. Someone said that the plates rust and I that that does happen with some diamond plates but by the time that happens you are down to the steel plate and you most likely need a new plate anyway.

    • George
      I have dmt plates and had the same problem. I contacted dmt and they said to scrub them with a washing up sponge pad with some Ajax on . They cut better after I did that and also looked cleaner. Don’t worry about scrubbing too hard,they said it would be fine.

      Ric.

  5. Paul,
    I bought an “extra coarse” and an “extra fine” DMT plates after I saw you doing a sharpening demo at the Rockler in Arlington, Texas over 8 years ago. You were only using the 2 plates with a strop at the time. I was a bit surprised to see that you added a third. That being said, I’ve got a bunch of sharpening jigs, stones, etc, that I haven’t used since I saw your demo. Freehand sharpening using the 2 plates and strop are working great for my chisels and planes. Do you use the same setup for knives? I’ve tried but only get mediocre results. Do you have any advice to sharpen knives?

    Thanks for saving me hundreds in sharpening gear over the years!

  6. Hi Guys,
    I am a complete amateur, so I got “sucked in” to all kinds of views about sharpening. I used abrasive paper on glass, I have plenty of waterstones which worked well, but maintaining them was a pain. Recently I acquired a Trend diamond stone and I use WD40 as a lubricant (thats what I had in my toolbox). I like it, it is easy, no fuss and works well, at the end I strop. It came with an eraser (rubber) for cleaning the surface. It works fine, so maybe if you have problems cleaning the surface you may try it. Just a normal stationery eraser.
    Hope it helps.
    Regards,
    Norbert

  7. Its funny really . For the best part of the last 40 odd years I have used one slate oil stone which I pinched off my dad (He for some reason had two ) ! I have know idea what grit it is, I think I have washed it twice and cant remember ever checking to see if it is flat and I use 3 in 1 oil . I resort to a gridstone or belt sander if an edge gets damaged . The only strop I have ever used is the palm of my hand ! I am a working carpenter making my living fashioning wood . I am always being complimented on the condition of my tools and their sharpness. So I think people make to much fuss and have to agree with Paul that whatever technique you use it has to be quick and produce a strong long lasting edge or else you are losing money.

  8. There is a technique I use to remove swarf as I sharpen. Unless you have a faulty plate I cannot give a reason other than clogging. My stones still cut wel after years of use . They are EZE Lap.

    • I’m sure I’m doing something goofy that is spoiling the coarse stone that eventually I’ll figure out, since you have such good performance.

      May I ask two quick questions? First, how much pressure do you use when you are lapping? Do you feel like you are really bearing down and that lapping for an hour would be a huge amount of work? Maybe I used too much pressure on the stone?

      Second, you show how you use the superfine stone to remove the wire edge when grinding and honing. When I do that, the superfine scratches and spoils the polish on the back of the blade. Should I just ignore those scratches, it’s part of the work, and makes no difference? Sometimes I can remove the wire edge on the strop instead of the superfine to avoid this, but if a lot of grinding was done, then the burr just digs into the strop.

      • Persevere and you will gain just what you need.
        Re pressure. I do apply quite a lot of pressure but not too much.. Also if the iron or chisel is hollow I do not try to get the hollow out at all. Just focus on the 1/2″ or so beyond the cutting edge and that will work fine. I wouldn;t worry too much about scratch marks in the surfce and superfine polishing, try the tool and see how you feel about the results. Results are what matter.

  9. I have a Veritas MK II Honing guide. Can I use this guide with the diamond plate? Will it damage the brass wheel that rolls on the stone?

    • It’s fine to use the Veritas guide on diamond plates. There is always some reduction on wheels on stones of any type, but not noticeable.

  10. Regarding flattening the backs of chisels (and plane irons), is it necessary to go through the wet-and-dry sandpaper series before getting to the stones, or does the sandpaper stand in for the diamond stones for those of us who don’t have them yet? Thank you.

    • Hello again, Yes, use the abrasive paper first. Don’t sweat this like some obsess about and please don’t fall into the trap of the scary-sharp method except as a very temporary fix in lieu of getting good sharpening stones or plates as soon as you can afford to. I usually go through the grits from 250, 400, 600, 800,1200,1600, 2000, 2400. From there I go to a flat block of wood, plywood or MDF. Don’t obsess over the flatness of this either as the pressure you apply compresses the wood and so catches the whole surface of the back. Keep you abrasive papers well flushed with water to float off abrasive particles and steel as this can round the corners to the flat face slightly. From this point on, when you have the back flat and polished out, you never need do this again. Just use a strop, even without buffing compound on the leather, to break the burr from the cutting edge if there is one.
      You can buy the abrasive from any auto store, Autozone is fine.

  11. hi every one i dont know if this is the place to ask this question but cant find anywhere else so here it goes. i have a couple of swords and daggers and also a couple pocket knives that get alot of use they need to be sharpened i want to get them as sharp as a razor or as sharp as possible. i have tried some of the handheld sharpeners and also table mounted sharpeners that you pull the knife through and didnt get very good results certainly nowhere near what the companies that make them claim. so my father gave me a very fine sharpening stone (looking at it it almost has the look of a block of metal but its not just very fine now i have heard some stones are ment to be used dry just as they are and others made to be used with water on them and even others made to be used with oil on them as lubrication. now my question is how do i tell what kind of stone it is i dont want to mess anything up using it the wrong way is there any way to tell if they are ment for oil watter or dry? please any help would be much appreciated
    -dave

  12. Dear, well everyone i suppose….has anybody here including yourself mr sellers tried the average rubber erasive to try on your diamond stones just to declog and add a bit of life back in them??…try it…i have all the worlds of sharpening…you name it diamond plates, diamond paste, waterstones, strops, stropping compounds and ill just safely and wisely say that i use them all in fairness to get the edge that works for me…and yes the effort is unreal an my arms are like…massive..but that be the foreplane to thank mainly but for me that effort shows in the time that edge lasts and the finish it leaves behind….and mr sellers…youre an inspiration to very many and your work is amazing its been a pleasure to have seen your vids on youtube i hope to be as successfull but i doubt with my mentality that will be possible…but boy do i love to make some craking stuff 🙂

    • My experience with Trend is that the diamond plating peeled off after a short time whereas I have never known DMT or EZE-Lap peel off. I don’t use DMT though I have used them on a very limited basis. I think that EZE_Lap have proven themselves to me. I have bought them over the past 15 years and they’ve never let me down yet.

    • Trend is crap. 300 grit side lost peeled some diamond shaped leaves. The 1000 grit side blistered up on a spot near the center of the stone.

  13. It appears that Eze-Lap no longer offers an 800 grit, will 600 grit suffice as an intermediate? Also, are your stones 3″ x 8″ x 1/4″ Flash Diamond Stones? Thank you for your time.

  14. In your opinion, what is the best way to clean a diamond stone if it has clogged? Like on the tip where everything gets wiped off. I’ve read that a household abrasive cleaner and a tooth brush would work.

    • Mineral spirits and a brass wire brush will un clog a diamond stone pretty well and a regular clean with an ordinary eraser will keep any particles building up preventing clogging

    • I haven’t had my diamond plates clog so I assume it’s because I use auto glass cleaner. Just a regular nylon nail brush and warm soapy water is generally recommended by EZE Lap and DMT makers.

  15. I was using only water on my stones and trying to flatin my plane blades it seams to take over 8 hours to do. But after using glass cleaner it cuts so much faster than just water thanks so much for your tip on using it. Now if I can fix my ocd of having to flatin the back and front of my plane blades and chisels to a mirror finish.

  16. I plan to buy DMT diamond stones, but do not know if I should buy the continuous surface stones or the ones with the perforations (that presumably hold swarf for better sharpening). I am new to woodworking, and simply do not know enough to determine “fact” from “marketing.” Any suggestions are appreciated.

  17. Glass cleaner on DMT works fine for me. It works fine with wet/dry paper. A reputable dealer who sold me ceramic slips for carving tools told me to use water as lubrication. (That’s pretty close to glass cleaner.)
    I have a couple Arkansas stones (hard; translucent) and I can’t see why I shouldn’t use the same bottle of glass cleaner as I use on everything else. I like your use of the term “snake oil”. What’s the difference between spending five minutes or, say, seven minutes? All I care about is a sharp, sharp edge that will reasonably hold up while doing the work.
    I have no idea about glass/ceramic, and haven’t the inclination to spend the time on research.
    I bought a reproduction Viking whetstone (it hangs on a cord around my neck because it feels nice and smooth). When I polish my Buck knife on the stone (said in the literature from Finland to be Jasper), the Buck knife takes a polished sharp edge I can’t get any other way. The stone itself gets cleaned when I shower.
    I just can’t see any difference, and when you say in your video that glass cleaner smells nice, I find myself nodding my head.
    As long as I keep a reasonably consistent free hand angle on grinding, honing and polishing, everything seems to work well, and a bit of water with an emulsifier in it (soap, glass cleaner, whatever), what on Earth is all the fuss about?
    Why would I introduce oil if it is entirely likely that some Medieval guild-master had a source of supply and wanted to make some extra income.

  18. Very informative. I’ve been losing sleep over which sharpening system I should use but the more I read into diamonds the more I like about them. Excellent blog!

  19. I use an India combination oilstone freehand for the secondary bevel and a sharpenset grinder when the primary bevel need to be done. Went through the whole gamut of diamond stones and decided that if the oilstone was good enough for generations of tradesmen it was certainly good enough for me.

  20. Mr Sellers,

    Thank you so much for your blog and youtube videos. Watching you work and teach has improved my woodworking results for sure, but I also get even more enjoyment out of my shop time now.

    My question is how large of a diamond plate do you recommend? I immediately want the EZE-Lap 3″x8″ stones, but I can save $30 going with the 2″x6″ size. Is the extra area worth it?

    I have a bucket of old chisels, 4 planes, and a few gouges from my grandfather. My father never used them. They are 1920 era tools than have been gathering dust and rust since 1980. I want to restore them for sentimental and practical reasons. I just finished restoring a 1″ chisel, and it took me nearly 20 hours with emery cloth and sandpaper. I’m quite happy with the results, but I think I’m ready to invest in a quicker method. Also, I went through a fair amount of paper, tape, and spray adhesive, so I think in the long run, sandpaper is probably more expensive than diamond.

    I’m thinking of buying the 3×8 double-sided Medium/Fine (DD8M/F) and also a smaller 1×3 extra coarse (21XC).

    My thinking is that the 3×8 double-sided will serve most of my regular needs, but I can use the small XC when I need to remove a lot of material during the restoration process. The extra coarse plates are a lot more expensive than the finer grits. I assume this is because the larger diamonds are more expensive to produce.

    Anyway, I welcome any comments or advice from anyone.
    James

  21. Someone says that the 1,000/6,000 combination of King Two Sided Sharpening Stone’s grit is not ideal for sharpening very dull cutting tools. Do you think so?

    • Yes, initial restoration would take too and can make a simple task laborious in the scheme of thing. I would suggest something much more coarse for initial restoration of what I call a ‘thick’ edge, maybe something between 150-400 grit. Then I would work on a more rigorous sharpening regimen using more frequent sharpenings on the 1,000 stone and if necessary, for an ultra refined edge, on the finer 6,000.

  22. Paul you are always careful in your videos not to let us see the exact ‘glass cleaner’ you are using – presumably to avoid any endorsement issues. When I look for glass cleaner in Halfords for instance, they all seem to contain some wax additive to make the glass hydrophobic, which doesn’t sound like a good idea in a cloggable diamond plate. Are you able to be a little more specific about what’s in the cleaners you use, or even name them?

  23. Mr. Sellers. You are a gift to us all. I only wishI had you as a teacher when I was young. It would have saved me a lot of headache and a lot of money.

  24. After reading Mr. Sellers response, I had to chuckle…you just can’t wisdom resulting from experience and the conclusions drawn from that experience. An example…some years ago, I got so sick of the constant evolution of shaving razors, (1-blade, then 2, 3, 4, pro-glide, on & on), all with a different attachment jig, meaning you had to buy a new razor w/each evolution. It dawned on me that a long time ago, guy were getting Baby-Butt-Smooth shave with…..a straight razor! And so, I bought a couple, and in that time, have shaved hundreds of dollars, (a little play on words), as well as knowing that I’m no longer contributing to the vacation fund of the Execs. at Gillette. One of the wood-working gurus some of you have probably tuned into used to be a sales rep at Lie Nielsen, and now represents Wood River…he used to talk about sharpening, and 8000 grit was the pinnacle…now on his website he offers what is called the Minimalist Kit offering a 300/1000 diamond stone and a Ceramic 16000 stone for $443. The kit go up from there, all the way up to $1374.00. Now, I watched a video of Mr. Sellers where he sharpened a hand plane, using the method he described, placed it on a board edge, looped a rope/string around the front knob, and pulled a full length shaving from the board. Like he said…Marketing!

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