Thread: Yeloow Slurry Stone for Yellow/Blue Stones?

I am so lost!!!!
Blue, yellow, green, yellow-green, blue-green..... OMG I so love stones that give grit sizes

Is there anyone, anywhere, that can actually say for certain, what grit, any natural stone is?????
or is it all just a matter of opinion????

The fact any stone was used as a building stone or garden rock has nothing to do with its inherent qualities. Some people are buried in solid gold coffins. The fact is the belgian Blue is a honing stone with cutting qualities around 6K and does put a very fine polish on your blades. Yes its very slow and maybe there are better choices but it does work.

Originally Posted by gssixgun

Is there anyone, anywhere, that can actually say for certain, what grit, any natural stone is?????
or is it all just a matter of opinion????

I've thought about this very question WAAAAAAYYYYY more than a normal person should and off and on for quite some time.

If I had more time and even more initiative and motivation, I'd snap pics of razor bevels exhibiting magnified scratch patterns of known grit sizes (Shapton stones). Then....pics of scratch patterns of natural stones. With the right equipment with high enough magnification, one could measure the distance between the peaks in the scratch patterns of various stones and there ya go, put them in order of scratch distance. Of course, the scratch patterns of any natural stone would only in itself be an average if you had a few of the same stone to use for comparison since.........and, I'm bringing this off topic post full circle.........here it comes..........natural stones are varied in composition, sometimes to a significant degree (no two natural stones are identical).

Chris L

Originally Posted by English

I'm not, and that' why I said it's a low grade.

Your statement implied that your low grade Japanese stone was worth comparing to your Escher because you offered a side by side test of the two.But if it's not a high quality stone then there is no comparison to begin with since the Escher is the highest quality stone of all the European varieties.

I think you'd be happily surprised to find out how nice the higher grades of Japanese polishing stones are. Old_School has some really nice ones in stock right now, as does Mr. So at japan-tool.com.

Originally Posted by English

Sorry, my words are heavy handed. I don't mean you guys don't know what you are talking about.

I'm not looking for a fight and your points as always are of course perfectly valid.

Same to you, you have obviously used and appreciated some very fine rocks, kudos. Hopefully someday we can have the chance to trade and compare finishing stones, I know I never get tired trying new ones.

This is a good thread. I appreciate the debate gents.

Originally Posted by gssixgun

Is there anyone, anywhere, that can actually say for certain, what grit, any natural stone is?????
or is it all just a matter of opinion????

No, there is no set grit size for natural stones because the type and concentration of grit plays such a large role in how the stone cuts. The binding material is also a factor because it alters how much grit is released in the slurry.

Originally Posted by thebigspendur

Some people are buried in solid gold coffins.

Ah yeah, it's an old custom in Transilvania... some people say that's how the country became so poor.

Originally Posted by gssixgun

I am so lost!!!!
Blue, yellow, green, yellow-green, blue-green..... OMG I so love stones that give grit sizes

Is there anyone, anywhere, that can actually say for certain, what grit, any natural stone is?????
or is it all just a matter of opinion????

I don't think it's a matter of opinion, the problem is that whoever was playing with the lava and the clay was either mean or illiterate and didn't bother to stamp the numbers... Good thing we've gone long way since then and capitalism is finally providing

Originally Posted by Chris L

one could measure the distance between the peaks in the scratch patterns of various stones and there ya go, put them in order of scratch distance. Of course, the scratch patterns of any natural stone would only in itself be an average if you had a few of the same stone to use for comparison since.........

Actually that distance doesn't relate to grit. I'll explain below.

Originally Posted by Russel Baldridge

No, there is no set grit size for natural stones because the type and concentration of grit plays such a large role in how the stone cuts. The binding material is also a factor because it alters how much grit is released in the slurry.

Yeah I think Russel is getting there. Here's a quick reference on what grit is Mesh (scale) - Wikipedia, the free encyclopedia

Basically most abrasive materials are composed of cutting granules and when they are produced industrially the size of these granules can be controlled to be uniform to a rather high precision. In natural stones the size of the cutters is determined by the crystalization process and there is a whole range of them. If you would go by the industrial definition i.e.the smallest sieve through which the coarsest granules pass you get a lower bound on grit, but since there are so few of these particles that may not really be a good definition. Of course if I give you a 4 cubic micron of a stone there are so few granules in it that it will have a very specific grit, but that's a rather tiny stone.

Anyways, what I'm saying that even if you ignore the variation between various veins etc, in any normal size natural stone there is a wide range of abrasive granules which translates to a very wide range of grits. Some sites claim that in japanese stones these granules break down during honing which if true means that you have a dynamically changing grit.

I would point out that 8000 grit (3microns) of diamond granules will cut very different than 8000 grit of for example SiC or CrO. So even if you can grind down a coticule, extract the garnets, sort them and then make a bunch of synthetic stones out of them with specific grits, they will cut a whole lot finer than the corresponding girts made of diferent abrasives. It's just a matter of crystalline structure and how sharp of corners you get.

Finally let's consider an 'effective grit', i.e. what is the effect of abrasive A on steel and how does it relate to say diamonds of various grits. The important part is not the distance between the striations, but rather the striations itself - the width and the depth of the average one. Since the garnets are rounded and diamonds are sharp the diamond striations of the same width will be most certainly sharper than the ones produced by a garnet. And if you imagine the very edge where the two ridges meed you will quickly realize that it is more the depth of the striations, not their width that matters - the shallower the better.

So, now that I'm done with all this I'm off to kill manbearpig. Tell the Nobel commeetee that I'll be back for the ceremony and I plan to use 1% of the prize money on razors.

Wow I do love a good barney! I look forward to seeing all these rocks at Brum! For my two-penn'orth I think it's horses for courses - I use BBW, cotis, thuringians, japs and chinese stones in different combos on different razors. As far as i am concerned, as long as I get the result I need - a shaving edge - I don't really care what stone will give it to me as long as it's there, as I need to be able to hone any razor that comes through the door. I do like trying new things out though and purchased what the seller called a 'turkey stone' from a flea fair (as in from Turkey, I think - well I hope . Lapped it up and it cuts quite well. Never heard of it though - wonder if he'd just dug it up out of the Teme river? The point is that it does work - though I don't use it for pro work as I haven't really 'validated' it to my full satisfaction yet - cuttting at I would reckon the same pace as a 2-3k grit but quite smoothly. Result!

I do have this mental image though of guys on their knees in the Parisian streets furtively honing their razors back in the 1900's!

I've read about these Turkey stones!
I don't know what they are stuffed with though, but I believe they were used on edge tools.

Originally Posted by English

I will bring a coticule and rubbing stone, a grey Thuringien and rubbing stone and a green yellow Thuringien (Escher) and rubbing stone and a low grade Japanese natural hone with a rubbing stone to Birmingham. You can feel the differences and decide there which one is "worthy". Seeing is believing.

I must have missed something here. AFAIK all the hones you have mentioned here, all have different cutting properties from each other. From what I understand too, a YG Escher is a final polishing stone, a coticule can also be a final polishing stone, so I fail to understand the logic behind the above argument. I also don't see the point/logic in discussing the properties of a "low grade" natural Japanese hone.



@ The OP. There no reason you can't use the yellow rubbing stone on the blue hone. Ideally though, the slurry formed, should be the same as the stone you are using. This can be done in various ways. With a piece of the same stone, with a diamond hone, or with another much harder stone, that won't alter the cutting properties, of the hone you are using. In my limited experience, coticule is a soft hone, and therefore you will end up with a yellow slurry on a blue Belgian, thus having a different effect. Might be noticable and then again, it might not be noticable at all.

YMMV