SV30 on Shapton Glass results

outlandish710 said:
The usual advice is to use more pressure to release dulled grain, you advocate using nagura more often instead. Makes sense, the nagura is harder than any knife so it will do a better job.



Yeah I use 400 grit for 2k GS.



At that point, if I was seeking an even flatter, flawless grinding surface, I might weight cost of buying high quality diamond stones against simpler methods, i.e. SiC paper on glass (afaik Paul Seller's method). A sheet of paper is €0.30 or so, I'd have to go through 260+ sheets before the atoma (local price 80€) becomes more economic - altough it would probably more pleasant to use than fast-wearing paper.



Hm that makes sense although still quite vague (unsurprisingly bc industry secrets). Maybe the trick is to use softer sinterable elements (dk which) along with high purity alumina to get a ceramic bound that is soft enough to be used in hand grinding. I'm assuming the 'clay' used is not a naturally occuring product (low alumina content in these) or at least purified. As per https://www.klingspor.de/en/lowdown-on-grinding 'Ceramic' here apparently refers to both to the bond (sintered ceramics) *and* the type of abrasive - agglomerated grains like the type used in cubitron etc. i.e. structurally but not chemically different material.
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The use of pressure to "release grains" is greatly misunderstood. Not all the abrasive releases on stones so you get a glazing effect from the dulled abrasive left on the stone. This is also the reason you can get a higher polish than the grit rating would suggest. The greater the polish the stone creates the less abrasive its likely to release. Stones that release more abrasive tend to produce duller and hazy finishes.

I use lapping and a Nagura to refresh the surface because its "used" after sharpening. I recommend this with all stones for the above reasons but even more with Shapton stones because they are very hard and the surface texture of these stones is very important.

Im sure there are lots of differences in how its done and defined but Bauxite is a natural clay found just below the earths crust and is the main ingredient in ceramic production. How Shapton does it is likely very different but they have yet to release such information.
 
It's a lot more complicated. This is a GS8k:


shapton8k_01.jpg

shapton8k_02.jpg

shapton8k_03.jpg
 
ToddS said:
The large grains are aluminum oxide. The long crystals are the ceramic "binder"
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Are the extremely oversize grains a common occurrence in Japanese whetstones, or is it peculiar to Shapton? JIS R 6001 #8000 is not supposed to have any grains larger than 6.0µ in it; do any manufactures actually follow that standard?
 
Mr.Wizard said:
Are the extremely oversize grains a common occurrence in Japanese whetstones, or is it peculiar to Shapton? JIS R 6001 #8000 is not supposed to have any grains larger than 6.0µ in it; do any manufactures actually follow that standard?
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I really don't know. I'm not about to buy thousands more dollars worth of hones to find out.

My guess is that some try to mimic the structure of natural stones while others just put the correct sized grit in a variety of binders until they find something that works. I don't believe the manufacturers are basing their designs on a scientific understanding of sharpening. The surface finish is probably less important to their design than the type of apex they create and the sound and feel when honing.
 
ToddS said:
I really don't know. I'm not about to buy thousands more dollars worth of hones to find out.
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Of course. With the images you produce I forget that you do not have godlike powers to summon them by will. :)

If people were to send you samples (chips) from whetstones would it be worth imaging them or a waste of your time?
 
You will find varying grit sizes in all waterstones because it emulates natural stones and thats a bit of the goal. The Shapton Glass are actually pretty "scratchy" stones, as I call it. They are more like a diamond stone in finish than a waterstones finish. As the abrasive gets harder it more easily digs into the steel and makes very clean cuts. These cleaner and deeper lines tend to stand out as you increase the level of polish. The offset is steel hardness and wear resistance and often this makes stones perform in much different ways. Another reason I often mention "every steel has its stone".

Some of the most consistent stones are Naniwa and specifically the Chosera line. Its why I consistently hail them as the best for polishing and the extremely clean scratch pattern they leave. Im pretty sure Naniwa also openly admits to using a more closely controlled abrasive in the Chosera line.
 
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