Thread: Definition of Hardness in Water stones & Sigma Power Stones

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

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.

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

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. Hock also recommends #2000 for most purposes and #6000 only for the ultimate surface that won't need sanding, here.

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...

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.

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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

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).

Originally Posted by 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).

Thanks Ern,

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

Zelk

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.

Originally Posted by rsser

(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 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 and here. I must say that I have grown to like the 'mist and haze' finish that I get from my natural waterstones....

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Originally Posted by NeilS

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 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 and here. I must say that I have grown to like the 'mist and haze' finish that I get from my natural waterstones....

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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
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!).

Originally Posted by 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!).

Yeh, who do you believe?

I wonder whether the 0.5 +/- 1.00 micron () 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).

BTW is Mt Beauty near Bright?

Zelk

Originally Posted by zelk

Yeh, who do you believe?

I wonder whether the 0.5 +/- 1.00 micron () 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).

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....

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The authoritative analyses on the subject on how different sharpening mediums work is by Brent Beach 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.

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.