Questions on diamond sharpening methods, stones and plates

Question:

Hi Paul,

I bought your book recently, having never done woodworking before, and have very quickly gotten very confused about the act of sharpening.

First of all, I figured that diamond stones would surely be pricier than oil or wet stones, but unless I’m looking in all the wrong places, they appear to be of a similar price! I had hoped I could find a cheaper set of equipment to start out with, since my budget is limited – are there ways I can get started with sharpening for cheaper than these diamond and wet/oil stones?

Second question: the wet stones I saw seemed to list 8000 grit stones as extra fine, whereas diamond stones list 1200 as extra fine – what’s with the differences?

Third question: you wrote in your book about stropping with a 15,000 grit compound, and how critical it is to keep the bevel at the appropriate angle while stropping, which makes it seem a little fragile to me. Now, obviously I’m not the expert, but when working with stuff that fine I would have thought that the first few cuts you make with the chisel or whatever would bring the edge back down to a level that would make the 15,000 grit stuff a little over the top, wouldn’t it?

Last but not least, would I be able to get by with only using two different grit sizes instead of the three you use in your book, and if so, which sizes should I use?

Thanks,

LM

Answer:

Hello Luke,

Different sharpening stones and plates

I and many others abandoned different natural and man-made stones to adopt diamond plates for three main reasons; they last long, cut fast and stay dead flat. Over and above that they are cleaner, less messy, more convenient.

Two sharpening plates or three?

With regards to two stones instead of three. I started with three stones and then went to two only myself. A cost factor at that time. I felt then that I spent too much time on the fine stone and of course that stone wore down more quickly. I went back to three around ten years ago and never switched from what I had.

Are cheaper stones any good ?

Now as to cheaper stones. I have found that 1) Cheap stones scuff off the diamonds. 2) The particle size is greatly varied on most cheap stones. The deep scratch marks are hard to remove and translate into a blemished cutting edge. There are only two makes of diamond sharpening plates that I can recommend for long term usage. EZE Lap and DMT.

Is the 15,000-grit edge more fragile?

No, the edge is strong and long lasting because of the convex bevel that ‘backs up’ the cutting edge. We are not talking micro bevels here because I never use micro bevels because I found I returned to the stones much more frequently. Micro bevels are very different t secondary bevels. I would recommend a 30-degree, singe bevel over this but a wider macro-secondary bevel would work great too. It’s more a convenience thing for me. I can sharpen a chisel in a few seconds if I do not use a honing guide even though I appreciate honing guides guarantee exact grinding and sharpening angles. I also advocate mastering the convex camber method because we use the round so much for other aspects of work such as creating coves, creating hand cut arches and much more. This enables the bevel of the chisel to ride the concave being worked much more smoothly and very efficiently. So, no, the cutting edge is not fragile at all. Typically I can chop 30-40 mortise holes 4″ long x 1 1/2″ deep by 3/8″ to 3/4″ wide in oak without sharpening. Using my method to resharpen takes no more than one minute and then I am off again. It works and has worked for almost 50 years. I have trained myself to do this and it is very much a system that works. Also, the reason I mention keeping the same bevel for stropping as grinding and honing is that students and those new to sharpening tend to feel they should hone at a much higher angle and even roll the chisel edge into the strop. This does nothing more than dull the edge and cannot sharpen it.

Stone fineness

Re fineness indexing on sharpening stones and plates. It takes me thirty stropping strokes on the plane iron to go from 1,200 diamond grit to a 15,000-grit polish. I want to keep expense down to a minimum for everyone and of course manufacturers would like you to buy ten stones in between 250 and 8,000. I suppose I am saying I find the finer 8,000-grit sharpening plates unnecessary.

Hope this clarifies things for you and others. I will post the answer and your question on my Q&A blog.

Best regards,

Paul S

16 comments

  1. Luke says:

    Hi Paul, thanks for such a comprehensive reply! It seems like you definitely recommend a 15,000-grit polish on the strop, and a 1,200 diamond grit prior to the strop, which is good to know. What grit size would you recommend for the first stone when using a two stone plus strop setup?

  2. Hi Paul,
    I bought a Faithfull double sided diamond stone, one side 300, and the other side 1000. I think that the diamonds have been put on a bit thin, after six months the stone is not up to much.
    Great thing about your blog, is it has made me much mless trusting of manufacturers, for example I was talking to an owner of a real tools shop in Brussels the other day, and I mentionned Marples to him. He said they were now in one big importing group, bringing in Chinese stuff; and living off their name. Thus have the mighty fallen.

    • I think that this is my point. How can a company like Rubbermaid that makes plastic buckets and bowls know much about what we want. I wiouldn;t hesitate to bu a Faithful chisel even though their chisels are made in China too. They don’t hide it and they cost between ¬£2.60 and ¬£3.50 in both metric and imperial sizing. I have tested these for abpout five years and they have been consistently good and pleasing to use. They take and keep a good keen edge, are slim enough for finer cabinet work and feel just like any Marples or Irwin Marples for a third of the price. Buy these top get started and see how you like them longterm. I am still smitten with wooden handles.
      I cannot say with Faithful sharpening plates. From what I have seen, they fall short.

  3. Chip Lis says:

    Are there different grades or qualities of diamond sharpeners? I have used these sharpeners for many years, like about thirty or so and recently was listening to some old guy, I’m 53,say that he’s had his diamond sharpeners for about three or four years and they haven’t lost their quality. He’s either full of shit of just hasn’t much experience, I say the latter. He appears to me to be the therapeutic type of “carver” sharpening his knives and chisels. I’d appreciate some more knowledge over questioning some old guy’s skill level and knowledge. Chip

    • There are different grades from extra coarse to superfine and even finer. Here at the school the plates last for about five years, but that’s multiple users. In the scheme of things I think that that is about 25 years of daily use. I have tried all of the plate manufacturers and found EZE-Lap to be the best overall sharpening plates for consistency, longevity and pound-for-pound best value.

      • David Baker says:

        Paul,
        I’m new to woodworking and I’m very appreciative of the time you take to invest in the aspiring enthusiast. What is the optimal width of the stone for flattening the back of the chisel? I noticed in the video that you had already flattened the chisel. Can this be accomplished on the stones you use in the video. Also, I just picked up a set of Stanley Sweetheart Chisels. I’m curious to here you comments on them.

  4. simo says:

    Hi Paul – I’ve just watched your sharpening videos for plane irons. Great stuff…

    I’m on a tight budget for a set of diamond stones but notice EZE do some 3×2 inch size versions. Do you think these are too small for working a set of chisels and a 2″ wide plane iron ?

    Please say they’re not, otherwise I’ll have to not eat for a couple of weeks :)

    • Darrell says:

      Simo,
      EZE Lap diamond plates are available through Amazon, and I think the prices are quite reasonable. I’m like you, on a tight budget. My plan is get 1 diamond plate each month or 2. I figure that way I can start to use them, or just keep using my existing sharpener until I have them all.

      http://www.amazon.com/s/ref=nb_sb_ss_i_1_7/189-0097124-2557257?url=search-alias%3Daps&field-keywords=eze%20lap%20diamond%20stone&sprefix=eze+lap%2Caps%2C737

      Cheers!
      Darrell

      • simo says:

        Thanks for the link. Shame I’m not in the USA ! these stones are more like 80 USD over here in the UK, hence looking at the smaller sizes.May have to look into the shipping costs…

        • I think some of our US cousins may not realise that the premier US and Canadian made planes cost those in Europe and here in the UK about 30% more, so when we consider costs of simple tools like planes we have to really count the costs. Funnily enough, often UK made tools sell for one third less in the US. A Lie Nielsen 4 1/2 smoothing plane currently costs a UK buyer $465 whereas the US Highland Woodworking price is a mere $325. It looks about the same for Veritas planes also.

          • simo says:

            Hi Paul,
            Quite agree with the prices on new quality planes over here.

            So would you reckon the smaller plates are a false economy and maybe unworkable ?

            Btw – the blog is just great – i’ve learnt loads. Keep up the
            good work !

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