Definition of Hardness in Water stones & Sigma Power Stones

[thumbsucker]

Hi - I am looking for a fine honing water stone in the 8000 plus range I am looking at the Sigma Power stones from Japan Tool (http://www.japan-tool.com/).

So excuse my silly questions.

However I was wondering about hardness. What does it actually mean and what does it imply about the performance of the stone.

Now I have used king stones, and they are classified as soft. They wear down fast and need constant flattening, this has always irritated me about water stones.

However they cut relatively fast not as fast a diamond plate, but fast enough.

Now if the stone is harder, should this mean that it stone will remain flatter for longer?

However do harder stones cut as fast or slower then soft stones? Since the soft stones are constantly wearing away revealing new abrasives.

I borrowed a guys Chinese natural water stone, it was very hard stone in that it was slow to wear, but it just had no cutting power. After ten minutes of honing it would not turn a good burr.

Does anyone use the Sigma Power stones, do you have any comments on them? In the photos (http://www.japan-tool.com/toishi/jinzou/Sigma_Power/Sigma_Power.html) of them they are labelled as ceramic stones, not as water stones. Does this mean that they are not a clay medium, like the King's? I have heard that ceramic sharpening stones are very slow cutting.

I use only A2, or M2 steel blades and chisels for my work.

[Des.K.]

I have the Shaptons not the Sigma, but both types are ceramic, and therefore probably comparable.

The Shaptons cut quite fast, but they have a very different feel from the softer King stones, and may take some getting used to. I've found they provide a better feedback through the blade to the hands. They do remain flatter for longer, but they still need to be flattened regularly, though obviously not as frequently as the softer stones.

I've never used the Sigma stones, but I would say they would be similar.

Des

[NeilS]

Hi TS

Can't give you a definition of 'hardness' with waterstones, it's just a relative description mainly used with natural stones. Harder stones tend to be slower wearing (the particles break away less often to reveal fresh grit) and have, but not always, a finer grit size. They are the final polishing stone. You wouldn't try to raise a fresh burr with them, but polish the burr off. Rare natural stones can be both hard and aggressive (the particles don't break away but also retain their cutting edges for longer) but they come at a premium price.

Suggest you forget all about the Chinese waterstone, at least for now. It's not a good starting point for getting into waterstones.

I have some Sigma waterstones (1000, 2000 & 8000) and they do wear a bit slower than my Kings, but faster than my Naniwa. They say that the Sigma are better for high alloy steels, so may suit your A2 or M2 blades.

If you are looking in the lower grit range (I note you are only looking in the 8000 range at this stage), also consider a Bester stone, which is one of the hardest stones in the lower grits.

Having not used Shapton, I can't comment from experience, but understand the Pro ones sold in Japan stay flatter but also cut faster. Again a little bit more expensive than the Sigmas in the finer grit stones.

Natural stones are another story altogether....:?

No matter what the waterstone, I keep a diamond plate next to the stone and constantly apply the plate to keep it flat. The added advantage is the fresh grit 'mud' this creates which optimises the cutting power for that stone.

If you are shopping around, also have a look at Tools from Japan (http://www.toolsfromjapan.com/store/index.php?main_page=index&cPath=335_404). There is a currency option button at the top of each page. The postage costs have to be factored in for any cost comparisons, which of course will have also been added already to any local suppliers.

Hope this hasn't confused you more than helped you, TS.

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[rsser]

Hock goes into this in his 09 book on Sharpening.

The only thing that stuck with me was re the Shaptons; in hardness they're mid rated.

Haven't had a chance to try mine yet.

But with M2 my assumption would be that diamond stones would be the way to go. Eg. DMT D8EE

I'll take another look at what Hock says if you like. FWIW

Edit: did that; all I can add is that he says hardness is a function of the binder.

[thumbsucker]

I have ordered some sigma stones from Tools From Japan (http://www.toolsfromjapan.com/store/index.php?main_page=index&cPath=335_404_403). I got them at a much better price then what Japan Tool (http://www.japan-tool.com/) list them at.

While feedback on the Sigma stones are limited, my impression is that they cut faster then most, give a very sharp edge, and do not dish as much.

I should have them in 2 weeks.

I will post a review of them once I get them.

[rsser]

Look forward to it. Thanks Helmut.

[Mr Brush]

Helmut - those prices on the Tools From Japan site are certainly attractive for the finer grits of Sigma stone.

I'd be interested to know what methods they offer for shipping, and the approximate shipping cost for 1 or 2 of the Sigma stones. I have a feeling that they won't be that different to the Shaptons in terms of performance.:2tsup:

I currently use a Norton 4000/8000 waterstone for final honing. It gives good results, but is only slightly harder wearing than the King stones, so constant re-flattening is required. I'll be interested to hear what you think of the Sigma stones.

[thumbsucker]

Mr Bush - It cost me AU $50 shipping for four Sigma stones weighing in at 4 kg's via Air Mail. The two week wait is due to the fact that Tools from Japan keeps no stock and so they source the stones and pass them on to the buyer.

Tools from Japan were fast to respond to my questions and very helpful.

[Groggy]

Helmut, is that Stu from Tokyo?

[thumbsucker]

I was wondering the same thing.

The guy from Tools From Japan was an Australian and his name is Stu.

Doubt that there would be many Australian living in Japan both being woodworkers and both being called Stu.

So it is Possible.

[Sheets]

Stu from Tokyo and Stu from Tools from Japan are not the same entity.

Here is one: Stuart Ablett's Workshop (http://www.ablett.jp/workshop/)

The other: Tools from Japan blog. (http://toolsfromjapan.com/wordpress/)

[thumbsucker]

I asked Stu for some information on the stones this is what he sent me.


Well, starting from the low grit to the fine grit, here's how they work.

The #120 is one of the hardest coarse grit stones going. It will do a lot of work before it needs flattening, and I am of the opinion that if you can manage your sharpening well, you will never need to 'flatten' it. Besides which, it's a rough stone and is only really used for getting blades into shape.

The #1000 is again one of the hardest medium stones going. It should not require 'soaking' but a dunk in some water for a minute is not a bad thing. They soak up water very rapidly, and if you let the stone get too dry, it will clog a little and give a finer finish. But since you have the #2000 coming as well, keep it wet as much as possible. A squirt bottle of water will be a great help, just a shot now and then to keep the surface clean and swarf free. The #1000 does remove metal at a good rate, depending on the steel as well as a Shapton and stays even flatter. But if I had a choice, I'd choose a Bester #1000. The Bester do need soaking, but again it's only a minute. Just as hard as the Sigma, but the Bester chews metal up like there is no tomorrow. (And if you want to switch to the Bester, no trouble at all.)

By comparison, my

The #2000 is very similar to the #1000, but backed off a little in aggressiveness and speed. A dunk in water should be enough, and then keep the surface wet. Not much more to say, it's a 'refined' Sigma #1000.

This is personal opinion though. You may find they work better for you with just a splash of water or by leaving them in a tub for 5 minutes. I can tell you that compared to my old King #1000, these things are a dozen steps ahead everywhere, except maybe for outright speed. The King is about as fast, but you really need to be on the ball to prevent the King from dishing excessively, where the Sigma stones need far less attention. And the King needs to be submerged in water for at least 5 minutes, and then kept wet all day. A right pain really, but since I inherited the thing and it works well, I can't manage to convince myself to use anything until I wear it out. I am halfway there now after a couple years, so another couple solid years of use might see me looking for a new stone.

(Or it might have an imaginary accident with a hammer beforehand...)

The #8000 is not as hard, and is more conventional in it's composition. It only needs a splash before working, and is quite similar to a King #8000 except that it was formulated for tougher steel alloys rather than plain carbon steel like White steel and W1. It is 'quite' soft, but as it is a fine stone, that shouldn't be a problem and it will resist dishing very well. Maybe not as hard as a Shapton Professional #8000, but faster and resists dishing in the bargain.

Sigma happens to make and sell cooking knives, and these stones are designed for their knives, many of which are stainless steel and similar tough alloys, so they also produce a range of stones to get and keep their knives sharp. Just lucky coincidence that they work well sharpening all manner of blades and they are priced well too. It is quite common for professional carpenters here to go from the #1000 to the #8000 because the intermediate stone isn't really required for simple carbon steels as they often use here. The Sigma stones also work very well with the newer HSS planes and chisels that are becoming common here which are used on questionable and abrasive materials during renovations and new pre-fab construction.

Which brings me to a little tid-bit of information I discovered only today...

I read a few things, and ended up putting two and two together and, well, what do you know about M2 HSS plane blades?

You may not know this, but special sharpening stones do exist for HSS woodworking blades. King make a brace of #1000 stones, and I have them listed in the store. Sigma also make a pair of sharpening stones, one is @ #1000 and the other is 'fine' and they are a matched pair for HSS, but are available separately. They also make a special 'carbon' stone that uses a carbon based binder which is very tough, and the stone is graded at #700 grit. The #700 does not have many fans, but the pair of Sigma stones (sold as 'Select II) are quite well thought of.

Other stones do exist solely for HSS tools, but I am not as familiar with them as I am with the King and Sigma. The glut of diamond sharpening plates and stones (I only have plates listed thus far) have also been developed with HSS in mind and many are fairly recent products here, especially since HSS tools have only taken off in the last few years. Previously Blue steel was the 'tough' steel, but it didn't need any special sharpening methods.

Well, that's my thoughts on the Sigma stones. I really like them and I manage to sell quite a few of them with no complaints so far. As you might expect, these are rarely the first water stones for those who do buy them, so those who use them do have a basis for comparison.

I hope that helps, and I hope to hear back from you soon as I have the #120, #1000 and #2000 here ready to leave, and was planning on getting at least 2 of them out tomorrow. The #8000 stones take a long time to come in, and I am expecting it in the next couple days. I usually keep one on the shelf because they do take so long to get a hold of, but the last one ran away recently and I hadn't managed to get another in the mean time.

[NeilS]

Thanks TS for passing on that very useful info from Stu.

May have to take a closer look at the Besters (just don't ask how many stones I have already)...:B

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[thumbsucker]

Here is some more information from Stu regarding polishing stones in the 10,000 plus range.


While the Sigma #1000 is a great stone, I do believe the Bester #1000 is superior, and it's even a little bigger. The price difference is only 300 yen, and there may be that much difference between calculated and actual shipping costs (I always refund any extra shipping charges) so there may be no cost difference. If there is a difference after that, I'll cover it myself. If that works for you, let me know just to confirm it please.

With regard to the #8000 grit, I honestly believe that beyond this stone, you are looking at diminishing returns. Any #8000 stone will give an edge that is sufficient for most edge tools, most of the time. If a sharper edge is required, then how you get it should be decided by whichever method suits you best. This could be stropping, polishing with compound or a finer grit stone. Unfortunately, beyond #10000 grit the choices are limited because, as I said, beyond this point the need for something sharper is quite small.

I also think that with the Sigma #8000, any #10000 stone is not a big enough jump to warrant the money. Sounds odd since I am selling stuff, but I don't want you (or anyone) to feel short changed in any way. If you did decide to go with a finer waterstone, then it should be either something really special in #10000 grit, or something much finer than #10000 grit.

The current Sigma #10000 stone is in the same 'model line' as the #1000 and #2000 Sigma stones I list, the #8000 is not. What is strange is that many people are convinced that the #10000 was previously labeled #8000 grit. I cannot confirm or deny that, but the difference between the two is quite small in real terms. Very much a case of one or the other, but usually not both.

The Naniwa #10000 Superstone is, again, not a big enough improvement in my mind over the Sigma #8000. What you do need to realize is that the Sigma #8000 is above average. Not as hard outright as a Shapton Professional, but faster, thicker and resists dishing very well, which makes it a popular choice here. But the Sigma #10000 is just as popular...

The Naniwa Chosera (Ultra Ceramic) is a big enough improvement over the Sigma #8000, but they are not inexpensive either. From me, one would be 24995 yen plus 1000 yen or so for basic SAL/Small Packet shipping. Tools for Working Wood has them on sale right now, for US$225 or so, and if the shipping works, I'd have to tell you to take them up on it if you wished to use one of them.

The Shapton Professional #12000 might be enough of an improvement, but I wouldn't be confident in that statement until I had to the chance to compare them back to back.

The Shapton Glass stone in #16000 grit would most certainly give a sharper edge, they are very hard and strongly resist dishing, but they are very thin (5mm or so of usable material) and quite expensive at @9500 yen from me, and I don't have them listed yet, but I am considering it very strongly since outside North America, they are difficult to find. It would be a Japanese market Glass stone which are different to the American version, being specifically suited to Japanese blades. It was said that there was a difference in Pro stones too, but few could notice it. The difference between the American and Japanese Glass stones is easier to feel. Because they are not heavy, they cost about 600yen to ship via SAL/Small packet. Of course there is also the #30000 Glass stone at @26500 yen, but the jump to that is too far from the Sigma #8000 unless you are using a very small microbevel and actively work to keep it very small.

[NeilS]

Another useful slab of info, thanks TS.

Stu hasn't mentioned natural waterstones for grit sizes above 8000. They are not exactly a consumer product and perhaps not normally used for M2 steel, but they are in my opinion the next step if you want to go beyond #8000 and not want to go down something like the diamond paste path.

However I would be seeing how you like the edge off the #8000 before thinking of anything finer.

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[rsser]

Thanks for passing on the info Helmut.

When ordering a couple of Glass stones from the US the supplier couldn't tell me what type they were. Now I guess I know.

[thumbsucker]

I received the first part of my Sigma Power Stones that I ordered from Tool From Japan. I have posted my first impression in my blog here (https://kleinwerk.wordpress.com/2010/04/24/sigma-power-ceramic-waterstones/).

[rsser]

Ta TS. Sounds good.

The 8000 is JIS rating I take it, so about 1 micron?

[rsser]

I posted Stu a query about stones for lapping of plane blades, 120g Sigma or 1000g Bester. Here's his reply


The Sigma #120 is a very aggressive stone that should be used for grinding out chips in the edge more than anything. It is one of, if not the hardest of the coarse stones, but they really are not designed for flattening. They will do it, but I sure wouldn't want to be grinding out the resulting surface. These things scare me, just taking them out of the box to inspect them for cracks and chips, they really do bite.

The Bester #1000 is one of the best stones for maintenance work, where the blade needs to have it's geometry restored to a usable condition. Reshaping bevels and minor flattening. While it is fast, hard and an amazing stone, if the back is not already reasonably flat, you might be there a while.

For something like a manufactured plane blade that should already be close, the Bester is ideal to taking out the grinding marks. For something that needs serious work, then I highly recommend using another method, be it loose grit on a lapping plate, sandpaper on a flat surface or a diamond plate.

The newer plane blades such as Lee Valley, Lie-Nielsen and Hock, et al, the Bester may not even be required for the back, but with use, yes it will be required.

I usually get maybe 3-5 touch ups from a fine stone before I go to a medium stone such as the Bester, and at that point I will re-establish the bevel geometry and give the back a few swipes to make sure it's not getting out of kilter.

In your case, I assume the A2 blades are one of the above, and the HSS are either Mujinfang or some blades that Helmut has organized, then I'd have to say the Bester will be most useful.

I hate trying to 'sell up' anyone or anything, but in your case, it's best course.


FWIW my two Hocks have had to be lapped; a number of Veritas blades were flat or v. close to it.

I have a DMT Duo coarse/fine but that's had a good deal of work and I plan now to keep it just for flattening other stones.

[thumbsucker]

I would assume that is rated with JIS.

According to the JIS (Japanese Industrial Standard) rating an 8000 grit stone has a between 1.5 to 0.9 micron's abrasive particles. Examining the micro-bevel, I could see sections of very uniform, mirrored like regions. However spaced at regular intervals the bevel exhibited deeper furrows. This irregularity can be accounted by the known variance in grit size within a single stone.

Regarding the 120 grit Sigma stone, I took a chisels that was in a very poor state, and gave it a small work out (80 strokes) trying to flatten the back (which it did). Lets just say, that its like having a belt sander in a stone. It was like flattening the back on 40 grit paper that never looses its initial aggression. I would not recommend it for flattening anything close to flat. I intend to use mine as a flatten stone.

[rsser]

Sounds good Helmut.

I've ordered a Sigma 8000 on the basis of your blog report, and a Bester 1000.

[thumbsucker]

Sounds good Helmut.

I've ordered a Sigma 8000 on the basis of your blog report, and a Bester 1000.

:doh: me and my big keyboard. I am sure that you will be impressed. I look forward to seeing what your experience with them are.

[rsser]

No need to do a 'doh'! That was a very precise report. Thanks again for the link.

And it's good to have Stu's advice. He knows whereof he speaks. Along with Neil and you; that makes us fortunate readers.

[NeilS]

Thanks TS. A good read and looking forward to your further review.

On mirror vs misty finish, I'm a misty man now. All the deep scratches have to be gone, but I like a finish that sparkles rather than gleams.

That circular action is the way I learned to sharpen (the western way), but now work straight up and down the full length of the stone gradually working the width of the stone and rotating ends to more evenly distribute the wear pattern. Instead of one deeper depressions in the middle of the stone, this gives (for me anyway) two shallower longer parallel wear areas along along the stone. These require less stone to be removed to restore flatness and lengthens the life of the stone.

Ern, thanks for copying us in on Stu's reply on waterstones for lapping. I have a Sigma #120 for major rehab jobs, but must admit that I rarely use it... a bit agricultural, and in fact prefer the King #300 for less demanding rehab work and the belt sander for anything really serious.

Will be very interested to hear how you find the Bester #1000. I'm thinking of getting one myself to replace one of my #1000s (an old King that is quite aggressive, but as we all know quite soft and high maintenance, which I have passed onto one of my sons as part of their kitchen knife sharpening starter kit).

Hope you both enjoy your Sigma #8000s

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[rsser]

How do you use the belt sander Neil?

I can see the advantages in speed but hesitate to try it.

As for back flattening to minimise stone hollowing, I've just come across an article by Charlesworth that's v. instructive. TS and Neil, PM me your email address if you'd like a scan.

[thumbsucker]

Ern if the Charlsworth article is the one of waterstones by Fine Woodworking magazine. Then I already have it.

If you search long and hard, their are so many articles on water stones, and many contradict the other.

One common way to flatten a stone is to stick some abrasive to a lapping plate and then rubbing it back and forth. Which works however it has a problem.

Because all our bodies are asymmetrical in motion the stone will be flat but it is very easy to make the stone un-parallel. This then becomes a problem because as you sharpen you will need to push the blade more on one side, to compensate for the slope in the stone.

[rsser]

The article is titled 'Avoiding Hollow Waterstones' and was first published in the Furniture and Cabinet Making magazine. Republished in a UK Guild of Master Craftsmen collection titled A Guide to Hand Tools and Methods.

Yeah, it's a finicky business.

[thumbsucker]

Ern - I have sent you a PM with my email address.

The 1000 bester and 2000 Sigma came today.

I will do a full review on the weekend.

Both stones are significantly harder then the 8000 grit Sigma power stone. The 2000 being the hardest of the three. You can really feel the resistance 1000 Bester and the 2000 Sigma stones give when you try to flatten them. In comparison the 8000 Sigma feels soft.

Both the 1000 Bester and the 2000 Sigma where not absolutely flat, either having high spots along one corner edge. I was able to flatten the 1000 Bester with ease but the 2000 Sigma is very hard, and it will take some time to level it off.

Both stones produce very little muddy slurry however they go grey very quickly, meaning that they remove metal quickly. I soaked each stone for about 3 minutes, that is all it took for the bubbles to stop.

Stu was kind enough to throw in a very handy water bottle with a curved straw, that comes to a point at the nozzle. It makes adding water to the stones a breeze. Flattening the 1000 Bester and the 2000 Sigma is non issue as neither stone seems to wear to any great extent, during use.

I redid two blades on a combination of the 1000 Bester, the 2000 Sigma and the 8000 Sigma. The finish (Uniformity of scratch patter) I was able to get from these three is significantly better then what I can get from a 800, 1200, and 6000 grit sets King of waterstones.

The only thing I will add is that the jump from the 2000 Sigma to the 8000 Sigma may seem like a big leap however the 2000 Sigma performs well above what you would expect from a 2000 grit stone and the 8000 grit Sigma Power had no problem removing all of the deeper marks left by the pervious stone.

In my time I have used a few sharpening systems, scary sharp, diamond plates, diamond pastes and king water stones. I am confident in claiming that these Bester and Sigma ceramic water stones have given me by far the best edge, I have ever had.

In my review I will use three Lie-Nielsen bench plane blades. I will finish one using a combinations of King's, another on using Diamond plates and the the third using the Bester and Sigma ceramic stones. While it will not be a comparison of stone grits it will serve to illustrate the difference between the three systems.

[NeilS]

How do you use the belt sander Neil?



With great care! .....:said with tongue in cheek:

Actually it's easier than you might think. I wouldn't use it for flattening the back of blades as the platen under the belt is just not flat/firm enough, but for restoring the bevel on blades that have a bad nick or need a new geometry it's very effective. Start with the finest belt grit you have (can't remember what mine is) and go cautiously until you get the feel of how rapidly each grit size removes the steel......AND, no need to say, work with the belt running away from the edge. Perhaps start with an old blade you don't care about...:)

PM sent with email address for Charlesworth article, thanks.

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[NeilS]

Thanks TS for your initial review of the Bester and Sigma.

Yes, the 1000 and 2000 are much harder than the 8000, but you shouldn't have to work the 8000 that much as it's more of a polishing stone. My preference is to go to a 4000 or 6000 before the 8000. I find the jump from 2000 to 8000 leaves too much sharpening, and not just polishing work, still to be done on the 8000.

But people vary in their preferences.

Looking forward to hearing more on your Bester 1000.

.....

[NeilS]

The article is titled 'Avoiding Hollow Waterstones' and was first published in the Furniture and Cabinet Making magazine. Republished in a UK Guild of Master Craftsmen collection titled A Guide to Hand Tools and Methods.


Thanks, Ern. An interesting read.

I do something similar when flattening the backs of blades, but don't go so far off the stone as I don't aim for a concave back or use his movement across the stone.

Bevels I work up to the edges using a similar pattern, reversing ends at regular intervals.

Kitchen knives I hold oblique to the stone to get the maximum length in contact with the stone, again reversing ends at regular intervals. This will still leave a pair of diagonal corners out of the wear pattern that require regular flattening.



If you search long and hard, their are so many articles on water stones, and many contradict the other.



Yes, TS, waterstones are as much an art as a technology. They vary so much between makes (or mines in the case of natural stones) and everyone has a different experience of them depending on what else they have used. Our opinions also change over time with accumulated experience. I almost sold a stone at one stage that I couldn't come to grips with but a few years later it has become my very best stone.... the stone is the same, I'm the one that has changed...:U

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[rsser]

Good point.

Charlesworth says in that collection re one tool that he 'didn't make friends with it'. Nice expression.

Had the same feeling with my first waterstone, a 2 sided King. Disliked the flattening and the mess.

With knives on the Shapton glass stones I got the best result from lining the stones up on the bench side, pretty much locking hands and arms while standing side-on, and getting the swing across the stone by swivelling the hips. That was something of a necessity given the poor hand control I had and I adopted the idea from the lathe 'tango' in woodturning.

Looking forward to the Bester and the Sigma. Your accounts TS have whetted my appetite. Wonder what syndrome I have :-

[rsser]

Have been doing some lapping with the Bester now that it's arrived. Did a kind of comparo with the Glass Stone #1000 using 2 Hock A2 blades.

My impression is that the Shapton cuts quicker but the stiction is a pain, even with a drop of liquid soap.

Value for money the Bester would be the winner though. No stiction probs, lots more abrasive in the block and two sides to work with, and not that much diff in cutting performance.

The Bester performed very nicely with some Berg BE chisels. Cut quickly.

Will have a play with the Sigma 8000 tomorrow.

Stu's advice and service have been exemplary.

[zelk]

Are there any further comments on the Sigma 8000?

Having used King stones (1000 and 6000 grit) and the Veritas green honing compound, can I expect a much better edge on my Japanese chisels and A2 plane blades using a 8000 grit ceramic stone and would there be any need for the honing compound?
Zelk

[NeilS]

It will be interesting to hear how Ern has found his Sigma #8000.

On your question Zelk about going beyond #6000, this is as much about personal preference as anything. The performance of an A2 woodworking blade beyond #6000 is one of diminishing returns. Yes, #8000, #12000, #15000, #20000 or #30000 will all produce a sharper longer lasting edge but at considerable extra effort andhttp://www.hocktools.com/sharpen.htm cost as you go up the grit scale. If you enjoy using super sharp tools then you will venture beyond #6000, but for an everyday woodworkers a #6000 edge from a firm waterstone will do the job.

For example, Terry Gordon recommends the blades in his planes be sharpened to #6000 on Lobster waterstones, see here (http://www.hntgordon.com.au/sharpeningprocess.htm). Hock also recommends #2000 for most purposes and #6000 only for the ultimate surface that won't need sanding, here (http://www.hocktools.com/sharpen.htm).

The fact that you are honing your blades after the #6000 waterstone may indicate you prefer to go sharper than #6000. The issue with honing rather going to a higher grit waterstone is the latter will consolidate the edge as well as making it sharper. According to Japanese research a consolidated (compressed) edge will last longer. Polish doesn't equal sharper for longer.

The equation changes for your Japanese chisels, which will most likely be white steel or possibly blue. The high carbon white steels (and western O1) will readily take a finer edge than A2 and will definitely benefit from going above #6000. That is why most Japanese woodworkers use natural finishing waterstones that are generally #10000+.

Japanese kitchen knives are another game altogether and anything less than about #18000 on a blue steel hand forged knife would be a shame... IMO...:U

If you can manage to team up with someone in your area who has a few options above #6000 for you to try before you buy that would help you decide where your sweet spot is on the scale of diminishing returns. Pity you are not closer to me to come over and test run mine.

.....

[zelk]

Thanks Neil,
I must say, I do like the polished look after using the Veritas green compound, it feels like the honing is complete. After I use the compound ( on a piece of MDF ) the edge is sharper with not that much effort, I am just curious as to where would a #8000 Sigma fall within my current method of honing.
Zelk

[rsser]

The Sigma #8000 is JIS rated and about 1 micron. That's prob finer than V green compound (though I don't recall what micron the particles are in it and don't in fact remember reading about it anywhere).

I'm very happy with the Sigma; produces a mirror finish on HSS and HCS. Can't compare the appearance or performance though with fine honing compound yet.

(posted from the Vic Alps during a training rest day).

[zelk]

The Sigma #8000 is JIS rated and about 1 micron. That's prob finer than V green compound (though I don't recall what micron the particles are in it and don't in fact remember reading about it anywhere).

I'm very happy with the Sigma; produces a mirror finish on HSS and HCS. Can't compare the appearance or performance though with fine honing compound yet.

(posted from the Vic Alps during a training rest day).

Thanks Ern,

the green compound is claimed to be 0.5 microns, not sure if that JIS rated.

Zelk

[thumbsucker]

The 8000 sigma at 1 micron will give you a very nice sharp edge, but its not a shiny glimmer (The thing with micron rating for abrasives is that no abrasive is all at same micron. It is usually a range, this allows the abrasives to remove metal faster, but the wider the range of grits the less uniform and shiny will be). On the 8000 sigma the blade does not look sharp. I have found that taking the blade on to 0.5 micron diamond paste, and this take the edge to next level.

In short I suspect that the sigma 8000 is not going to be a major improvement over your green compound.

I am still aiming to do a full review I am however just to flat out at the moment.

[NeilS]

(posted from the Vic Alps during a training rest day).

Good on you, Ern. Wishing you sunny days and freezing nights!

Zelk, as the others have pointed out the #8000 Sigma would sit at about 1 micron (+/- a bit) and the Chromium compound at about 0.5 micron (+/- a bit). So, as TS suggests, you are unlikely to win anything by replacing the compound with an #8000 waterstone, although the waterstone and compound do sharpen in different ways.

These (http://ws.magicmrv.com/SP.htm) images of the surface finish off waterstones working through from #1000 to #10000 and then onto 0.5 micron chromium oxide are highly relevant to the discussion here. They certainly explain why TS feels the difference in going that little bit extra from the #8000 Sigma to 0.5 micron diamond paste, which I assume will do a similar job to the 0.5 micron chromium oxide.

Although an extra cost, an #8000 (1 micron) waterstone would be a good interim step after the #6000 (2 micron) waterstone and before a final light quick finish with 0.5 micron compound to get your more polished finish.

But, I do point out again that mirror shiny doesn't automatically equal sharp. If anyone is interested in this they might like to read Hock's blog on Matte Surface Mystery, here (http://hocktools.wordpress.com/2009/12/10/matte-surface-mystery/) and here (http://hocktools.wordpress.com/2010/02/15/matte-surface-mystery-part-2/). I must say that I have grown to like the 'mist and haze' finish that I get from my natural waterstones....:)

.....

[zelk]

Good on you, Ern. Wishing you sunny days and freezing nights!

Zelk, as the others have pointed out the #8000 Sigma would sit at about 1 micron (+/- a bit) and the Chromium compound at about 0.5 micron (+/- a bit). So, as TS suggests, you are unlikely to win anything by replacing the compound with an #8000 waterstone, although the waterstone and compound do sharpen in different ways.

These (http://ws.magicmrv.com/SP.htm) images of the surface finish off waterstones working through from #1000 to #10000 and then onto 0.5 micron chromium oxide are highly relevant to the discussion here. They certainly explain why TS feels the difference in going that little bit extra from the #8000 Sigma to 0.5 micron diamond paste, which I assume will do a similar job to the 0.5 micron chromium oxide.

Although an extra cost, an #8000 (1 micron) waterstone would be a good interim step after the #6000 (2 micron) waterstone and before a final light quick finish with 0.5 micron compound to get your more polished finish.

But, I do point out again that mirror shiny doesn't automatically equal sharp. If anyone is interested in this they might like to read Hock's blog on Matte Surface Mystery, here (http://hocktools.wordpress.com/2009/12/10/matte-surface-mystery/) and here (http://hocktools.wordpress.com/2010/02/15/matte-surface-mystery-part-2/). I must say that I have grown to like the 'mist and haze' finish that I get from my natural waterstones....:)

.....

Thanks Neil,

I understand where your coming from. Sadly, as I mentioned earlier, I am drawn to the shine like a moth to a light:U
Zelk

[rsser]

Heh heh, yes, it's a buzz.

Somewhere in webland I read that there can be significant variation in particles at single digit micron size so as posted, the rating and the actuality can be quite different.

(-1 in Mt Beauty this morning and blue skies; thanks Neil!).

[zelk]

Heh heh, yes, it's a buzz.

Somewhere in webland I read that there can be significant variation in particles at single digit micron size so as posted, the rating and the actuality can be quite different.

(-1 in Mt Beauty this morning and blue skies; thanks Neil!).

Yeh, who do you believe?

I wonder whether the 0.5 +/- 1.00 micron (:U) particles become smaller with use. This could at least explain why the tool surface becomes polished looking. To me the polished surface equates to the finest smoothing of metal. You can have a shiny bevel, but of course, this does not necessarily indicate the quality of the edge. The quality of edge will be dictated by the honing technique and when using compound, this may be the limiting factor, in other words, stropping or using compound on MDF could inevitably lead to some rounding of the edge which is less likely when using very fine grade ceramic stones. As Neil points out, consolidation of the tool edge is another issue and as some have pointed out, it appears that this is achieved mostly with natural water stones whose particles become smaller with use.

In Hock's articles, they talk about refraction of light off a tool surface when in actual fact they should be talking about reflection ( minor correction:rolleyes:).

BTW is Mt Beauty near Bright?

Zelk

[NeilS]

Yeh, who do you believe?

I wonder whether the 0.5 +/- 1.00 micron (:U) particles become smaller with use. This could at least explain why the tool surface becomes polished looking. To me the polished surface equates to the finest smoothing of metal. You can have a shiny bevel, but of course, this does not necessarily indicate the quality of the edge. The quality of edge will be dictated by the honing technique and when using compound, this may be the limiting factor, in other words, stropping or using compound on MDF could inevitably lead to some rounding of the edge which is less likely when using very fine grade ceramic stones. As Neil points out, consolidation of the tool edge is another issue and as some have pointed out, it appears that this is achieved mostly with natural water stones whose particles become smaller with use.

In Hock's articles, they talk about refraction of light off a tool surface when in actual fact they should be talking about reflection ( minor correction:rolleyes:).



I think your comments above sums it up fairly well, Zelk. The other two factor are grit shape and whether the grit is secure or free, both having some effect on performance and appearance.

Yeah, refraction through and reflection off. Not everyone remembers their high school physics, it's getting to be a bit long ago for some....:U

.....

[thumbsucker]

The authoritative analyses on the subject on how different sharpening mediums work is by Brent Beach (http://www3.telus.net/BrentBeach/) whose microscopic analyses cut through much of the hearsay that gets thrown about sharpening. This tends to make Brent a little uncompromising in his views, because unlike others he can back up his statements with photos and research.

In particular you should read his finding of stropping on leather or mdf (http://www3.telus.net/BrentBeach/Sharpen/Stropping.html).

He also has some interesting points abut water stone slurry. Old timers say that slurry is finer broken down abrasive ground down by the action of the sharpening, and you can get a finer edge with slurry. The thing overlooked is that an abrasive not held in place by a substrate will just roll past the bevel, at best it may dent your edge but it will not remove metal.

[rsser]

I understand that Alox in bonded form is sposed to break down exposing new sharp edges. IME silicone carbide in coated form breaks down fairly quickly and has a very limited life. No idea what's in the Sigma stones (shrug).

(Yes, Mt Beauty is in the next valley East of Bright).

[zelk]

The authoritative analyses on the subject on how different sharpening mediums work is by Brent Beach (http://www3.telus.net/BrentBeach/) whose microscopic analyses cut through much of the hearsay that gets thrown about sharpening. This tends to make Brent a little uncompromising in his views, because unlike others he can back up his statements with photos and research.

In particular you should read his finding of stropping on leather or mdf (http://www3.telus.net/BrentBeach/Sharpen/Stropping.html).

He also has some interesting points abut water stone slurry. Old timers say that slurry is finer broken down abrasive ground down by the action of the sharpening, and you can get a finer edge with slurry. The thing overlooked is that an abrasive not held in place by a substrate will just roll past the bevel, at best it may dent your edge but it will not remove
metal.

Interesting.

The last point on denting the edge may actually be be a burnishing effect on the edge which consolidates the edges rather than sharpening it.

I wonder whether using any compound should be with the intentions of creating a microbevel and polishing the back flat on a hard surface.

Zelk

[zelk]

(Yes, Mt Beauty is in the next valley East of Bright).

Beautiful area, used to visit friends on a tobacco farm in Bright many moons ago.

Zelk

[NeilS]

Haven't been to visit Brent's site in ages and found lots of new stuff there, including the section on stropping; thanks, TS.

Also noticed that he now accepts that knives require a different edge to plane blades in that they benefit from micro serrations. That's exactly why I like mist and haze (that's the micro serrations... like a micro bread knife edge) rather than mirror shiny knife bevels.

I think there is more to the slurry story than Brent asserts. A whole topic in itself for another day.

.....

[Halicon]

Being a sword polisher with soon two decades on his shoulders I can tell you that when I polish my Jap tools, Kanna's, Nomi's, Gouges and whatnot I always use a slurry on the finishing stone.
When I was a beginner I did not use this method and was thus rewarded instead with a clearer window into the Kamaji or whatever lamination iron that is used. Looks pretty but the Kasumi is kept to a minimum, especially since the foundation stages were synthetic (HRC 64-67 tools) with the exception for Aoto.

In any case, I noticed a rise in edge durability and a relief while working, with the Aoto mixed in instead of a synthetic. After a quick inspection it was a light Kasumi (haze, mist, this was before I knew about serration patterns). So I produced some slurry on my finisher and really brought out the Kasumi and 'lo and behold, the edge became much more durable and keener not to mention faster to finish (you can also save up the particles from the finishing stone and use for Uraoshi on the Kanban).
This process requires -very- fine pressure and control though. With slurry on and say an Ohiira Suita which is readily available today it's very easy to overgrind the iron, so make sure your fingers are at the very edge and don't be afraid of sacrificing some skin.

I don't see much reason to put such a polished edge on a western plane though. The nature of the tool isn't meant to polish and I would much rather use a Jap replaceable HSS blade for Arashiko (somewhat in the same league).

To the guys saying slurry particles will just roll past the bevel - it's all about keeping the water level in check. The surface isn't suppose to be overflowing with water. And often woodworkers use a finishing Suita type stone which ofcourse has the "Su" (Su-nashi is basically instinct now except for a few quarries, so won't bother bringing it up), catching particles and forcing them down to smaller size granted that you don't use Nagura (a big no-no on anything past foundation stones).
The topic of natural stones could be discussed forever but I just wanted to mention that in order to produce the very finest edge, Jap woodworkers use this method.

[rsser]

Thanks for that post.

It got me to experiment a little with a ceramic waterstone that I've not had much joy with, and letting the volume of slurry build up and dry a little helped a lot.

..

In terms of TS's original question about what makes a stone 'hard', this may be of interest: click (http://www.toolsfromjapan.com/wordpress/?p=564)

[Halicon]

rsser; Merely my pleasure to share with everyone. You get a much better result with a natural stone though since the synthetic particles in the ceramic stone are very hard to break down into smaller ones in order to create the different rows of serrations that appear on the edge with the misty appearance.

For example to name an entire kit for bringing out a very good edge. Sigma 1000&2000, Aoto (the sharpening stopped at Sigma 2000, the Aoto is a serration pattern refiner literally) -> hard and coarse Ohiira or Shoubudani Suita -> Finishing Ohiira Suita. If you want to go even further you can put the edge on a fine Nakayama Asagi and really bring out the steel but it's more cosmetic than an improvement.
That would be one of the cheapest natural alternatives depending on the stone sizes and shapes.

If you don't have the money I would say after Aoto then you will have to rely heavily on the Aoto to create the haze. That means you will have to spend quite some time on that stone and naturally flatten it very often since the Aoto is a rather soft stone (it comes in hard varieties but those are very, very rare and often have different particles).

So after the Aoto I would either use a Naniwa Jyunpaku or a Sigma 8000x. I don't see much reason bringing the edge further than that with synthetics since it will erase the haze.

All these stones are fit for any type of steel and any type of hardness, mainly tools though.
Now it's time to hit up the grinding stone again and go to work on some K120 pine fired steel :D

[NeilS]

.

If you don't have the money I would say after Aoto then you will have to rely heavily on the Aoto to create the haze. That means you will have to spend quite some time on that stone and naturally flatten it very often since the Aoto is a rather soft stone (it comes in hard varieties but those are very, very rare and often have different particles).



Hi Halicon

Do you have an opinion about the softness/hardness of Aoto from Tanaka Toishi Kogyosho? I have one on order via Kenneth Schwartz and would be interested in your views on that toishi.

.

[Halicon]

Tanaka? Is that a collector that went miner? I have to say I haven't even heard of it, and I have heard of pretty much all quarries that produced good stones, especially the ones around Kyoto with the "west stone" quarries that produces the best stones.

After having checked the prices he asks for, what they offer and a rough check on their quality I would say that it looks to be of the low to mid-end range. Many mislabeled stones in the purpose of earning more from the buyers. I do not dare to speak about the performance though, it has happened more than once that I have been even repulsed by a stone and later found out it polished extremely well.

You can ask the guy if the face of the stone is against the grain or with the grain. Depending on his answer he will prove if he knows anything about Jap nats or trying to sell something he has barely any idea about.
For an Aoto you have to do it along the grain, it should run straight and not horizontally like on polishing stones.

One more thing, anyone selling a Maruichi Maruka Nakayama Kiita for less than $2000 is selling a fake.
You should also watch out for newly quarried stones from the Takashima quarry. Don't bother asking why, just a heads up that will help you in the future if you go depper into the natural realm :)

edit: If you could ask Mr Tanaka from which quarry the Aoto was taken then I can give you a more detailed answer. Most "Toishi" (sword stones) Aoto's are on the softer side though.

edit2: Man, this is the first time I've been asked about Jap nats on a woodworking forum. This looks good! Anyone got a greenstone to spare? My euro collection of nats isn't finished without the greenstone :(

[NeilS]

Tanaka? Is that a collector that went miner? I have to say I haven't even heard of it, and I have heard of pretty much all quarries that produced good stones, especially the ones around Kyoto with the "west stone" quarries that produces the best stones.



New quarry to me, too. It's just west of Mt Atago. The Tanaka family have been mining their own quarry there for six generations. So it's a traditional family toishi business. Haven't got my stone yet, so can't comment on quality. Price is about $200 for an Aoto, which sounds about right. I've been told that the stone is 'not too muddy', so perhaps will not be a very soft stone.



...it has happened more than once that I have been even repulsed by a stone and later found out it polished extremely well


Found that with my Nakayama Karasu. Initially I couldn't handle it so went on to use less demanding stones but returned to it when I had developed more skills and now it is my preferred finishing stone.

.

[Halicon]

West of Mt. Atago would make it between Atagoyama and Ohiira. I have to say I haven't the faintest what kinds of stones would be produced from that place however.

By the looks of it I would never bring a sword to the kind of stones he sells. I'm guessing that he's focusing on tool stones especially with the offerings he has.

[thumbsucker]

I see that Lee Valley is now stocking Sigma Power Stones (http://www.leevalley.com/US/wood/page.aspx?p=67089&cat=1,43072,67175), I get the feeling that they reading these threads.

Lee Valley however are only stocking three grits, and their prices are nearly double what Stu from Tools From Japan (http://www.toolsfromjapan.com/store/) charges.

I also see Stu now stocks 6,000 & 13,000 grit Sigmas, I will send him an email to get his thoughts on these new stones.

[Schtoo]

I see that Lee Valley is now stocking Sigma Power Stones (http://www.leevalley.com/US/wood/page.aspx?p=67089&cat=1,43072,67175), I get the feeling that they reading these threads.

Lee Valley however are only stocking three grits, and their prices are nearly double what Stu from Tools From Japan (http://www.toolsfromjapan.com/store/) charges.

I also see Stu now stocks 6,000 & 13,000 grit Sigmas, I will send him an email to get his thoughts on these new stones.

I don't know if they read these threads, but the Sigma LV have are the Select II, for harder steels, I list both the Select II and Ceramic, and they're vastly different.

(What is ironic is that the description for the Select II at LV is a trimmed down version of what I wrote for them. Oh well...)

The pricing on the Select II is tight, I've tried to make sure that when it's all said and done, my pricing is competitive at least.

And Helmut, I'll reply here so all can read, ok?

The Sigma Ceramic #6000 is a formidable stone, it really is. Rightly aimed at the Shapton 5K as it's nearest rival, it cuts just as quickly in real terms, but stays significantly flatter, flat enough to remove any bevel rounding introduced by a coarser stone. It's one of, if not the hardest stone I've ever used. It just will not dish. It also leaves a good working, hair popping edge on tools and knives, very similar to what a Shapton 8K does.

Yes, I have one (as well as it's predecessor, a little softer) and I don't know, it's maybe on the edge of being too hard. Completely inert feeling on it, but it does work and work well. For flattening, I'd like to see something 4K from Sigma (and I'm asking them) because when there's a lot of steel on stone, it does require a lot of slurry control to prevent clogging. Only a smidge better than the Shapton 5K at resisting clogging, not enough to say "yes, it's better" with conviction.

(Perhaps slipping in the Select II 3K is a good idea here. Fast, quite flat and a moderate step for back flattening, which is useful.)

The Sigma Ceramic #13000, umm, yeah...

Completely pointless for chisels. Completely pointless for Jack planing. If you have a plane for smoothing, the steel can support the keenest edge and you are needing something that is beyond comparison, just get one now. I've not used mine very much to be honest, and I do have a lot of stones to compare to (at least 8 finish stones now), and this one completely blows my mind. Maybe the Shapton 30K is a fair comparison, but I don't know that they are as strong as the 13K is. It's hard, works as quick as you'd expect something with such fine grit to be, looks like scrambled eggs (it's called "egg colour" in Japanese) and, really it's best aimed at razor folks, because it'll leave a face shaving edge, off the stone. Passes the hanging hair test to level 2 (google it) on a chisel, which is astonishing.

If your stuck with Shapton and their grit rating system, the Sigma 13K is equivalent to a 20K Shapton.

I don't expect to sell too many of them, because they are quite expensive and quite academic. I've kinda put them into a category of "put up or shut up" because for the rather large price of admission, there's nothing else that even comes close. But it's right the way up there, and most folks really don't need the edge it can offer on their tools. In fact, the chisel I've sharpened with it scares me, and I've since 'blunted' it with a Honyama natural stone. Just plain old hair popping/end grain shaving sharp now.

Hope that helps.

It is really difficult to push the 13K because it's just so far beyond what's really useful in an edge, it's ridiculous. The 8-10K is, I think, I better day-to-day stone.

Stu, the Sigma shill. ;)

[rsser]

He's been posting on his tests Helmut, here (http://www.woodworkforums.com/f127/waterstone-tests-taster-stu-toolsfromjapan-com-129103/)and elsewhere I think.

Added: SNAP!

[thumbsucker]

Hi Stu

Thank you for the information. I am more then happy with the cutting speeds of the Sigma Ceramic stones. The Select II appeals to me in the coarser grits for hogging metal.

I am however interested in the Sigma power ceramic stone #13000 so I have sent you an order.

[NeilS]

I am however interested in the Sigma power ceramic stone #13000 so I have sent you an order.




Way to go... :tongueroll:... TS