Flattening Naniwa supper stone 100 and 5000 to 12000 grit

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tommytman

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Hello. Apologies I could not find an answer with searching. When a 12000 grit Naniwa is flattened with a 220 grit flattening stone the surface gets scratched up. It would seem to me that it could not be great to sharpen in that condition. I was able to flatten my 12000 stone but are the scratches from the 220 grit flatting stone going to mess up my razor honing? The diamond plates for flattening seem to have a similar grit so I’m guessing that is not a solution. Any advice is appreciated. I have some 1000, 5000, and 8000 Naniwa stones on the way and will eventually have to flatten them.
 
tommytman said:
Hello. Apologies I could not find an answer with searching. When a 12000 grit Naniwa is flattened with a 220 grit flattening stone the surface gets scratched up. It would seem to me that it could not be great to sharpen in that condition. I was able to flatten my 12000 stone but are the scratches from the 220 grit flatting stone going to mess up my razor honing? The diamond plates for flattening seem to have a similar grit so I’m guessing that is not a solution. Any advice is appreciated. I have some 1000, 5000, and 8000 Naniwa stones on the way and will eventually have to flatten them.
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Two options are either to use a fine grit silicon carbide powder or fine grit wet and dry sandpaper on a flat tile or piece of glass. Something like 600 and/or 1200 grit should work well for finishing the surface. I tend to also use fairly light pressure when flattening my stones with coarser grits to minimize the depth of the scratches. I mainly use 220 grit SiC powder or the Atoma 140 and 400 depending on the stone for the flattening. The Atoma 400 leaves a slightly smoother finish compared to the 220 grit SiC powder.

For the 1000 grit stone you probably don't need to worry too much about the finer grit but the 5000 and 8000 would benefit from the finer finish as well, particularly for straight razors or for knives you want a mirror polish, otherwise I wouldn't worry too much about it.
 
This is not first hand knowledge, but I could not find the threads to link but several people had said in the past that the first sharpening or two might be more aggressive than normal. I used a piece of float glass that was a scrap from a glass shop until the Mrs. Bought me the edge pro flattening kit. That may or may not of steemed from a fur baby knocking my scrap off the counter.

I also used an acrylic sheet until the silicon just scratched it up too much.

This thread may have some good information.v=
Thread 'How Do You Flatten Aluminum Oxide Stones?'
https://www.bladeforums.com/threads/how-do-you-flatten-aluminum-oxide-stones.1963828/
 
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so far what you have done is level the surface of the stone. In order for the stone to work according to its grain, it needs to be ground on silicon carbide powder 2 times larger than the grain of the stone. That is, a stone of 12000 on a powder of 6000, a stone of 8000 on a powder of 4000, etc. For stone 12000 after grinding, it is worth pouring water on the glass and grinding the stone on its own suspension. Then you will get a surface that corresponds to the grain of the stone
 
vlodko_lviv said:
That is, a stone of 12000 on a powder of 6000, a stone of 8000 on a powder of 4000, etc.
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This is extreme. I don't believe you'll have an easy time finding these super-fine powders and I don't think you need them. When used with harder stones silicon carbide is friable and breaks down in use. On softer stones, like the Super Stone, I don't believe the surface of the stone needs to be dressed that finely.

If you are polishing a near-solid dense sintered ceramic then the surface finish essentially is the "grit" of the stone. With a soft stone however the surface will break down in use and the binder itself is not hard enough to act on the macroscopic level. By this I mean that used edge-trailing even deep #220 scratches in the Super Stone will not transfer to the metal. You need only assure that there is not so much roughness that the edge of the blade is impacting the sides of these scratches when used edge-leading.

For the soft, rubbery Super Stones I do not to lap on silicon carbide out of concern that those particles will embed in the binder. For final dressing I have used a worn-in fine diamond plate or fine sandpaper. I'll have to try lapping on glass textured from lapping other stones with SiC; thanks for that idea.
 
Have you tried leveling and polishing the stones yourself? At least some? I ground several hundred stones, usually 1" by 6", but there were dozens of 2" by 6" stones. The stones were washita, tranlucent arkansas, norton, and Japanese stones, as well as diamond and elbor stones on a copper-tin bond. And I polished them all on silicon carbide powder
If you want, you can find everything:
 
vlodko_lviv said:
Have you tried leveling and polishing the stones yourself? At least some? I ground several hundred stones, usually 1" by 6", but there were dozens of 2" by 6" stones. The stones were washita, tranlucent arkansas, norton, and Japanese stones, as well as diamond and elbor stones on a copper-tin bond. And I polished them all on silicon carbide powder
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I dress most of my stones on loose silicon carbide and I have been outspoken about the superiority of doing so particularly on coarser stones, but that's a couple dozen not hundreds.
 
This might seem obvious but: if I flatten a 12000 and a 5000 Naniwa using the 220 grit flattening stone….. can’t I then rub the 5000 and 12000 stones together to smooth out the 12000? Or is it better to buy some SiC grit?
 
tommytman said:
This might seem obvious but: if I flatten a 12000 and a 5000 Naniwa using the 220 grit flattening stone….. can’t I then rub the 5000 and 12000 stones together to smooth out the 12000? Or is it better to buy some SiC grit?
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You can, but there is some risk of the 5,000 grit abrasive embedding in the 12,000 grit stone. This could matter of you are trying for a spotless mirror polish. But the same is true of using loose SiC grit if not moreso.
 
Thanks for the SiC link. Is there any reason to not use SiC for rock tumbling? It is pretty inexpensive and available in the 100-500 grit range
 
Gritomatic also sells a Jende glass lapping plate with SiC powder for an ok price. Anyone ever use that? Lee valley also sells a glass plate, plastic film, and sic powder. Not sure which to get.

I ended up placing a 500 grit sand paper on the non grooved side of the Norton flattening stone. After a bit of work the surface was fixed. But I need a larger work surface than the Norton.

Anyone use the jende or the Lee valey glass plate?
 
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tommytman said:
Thanks for the SiC link. Is there any reason to not use SiC for rock tumbling? It is pretty inexpensive and available in the 100-500 grit range
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That is what I use. I use black granite floor tiles. I started with glass but it ground down and became concave relatively quickly; faster than the granite I believe. Someone here recommended quartz composite synthetic stone countertop as the best long-lasting lapping base. Interestingly the saw-cut backs of the granite tiles are flatter than the polished fronts on mine; bring a straight edge with you if you can when shopping for them.
 
tommytman said:
Anyone use the jende or the Lee valey glass plate?
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Glass is best for grinding. But the glass must be taken with a thickness of at least 8 mm (about 1/3"). Further, if the glass is often used for grinding, then, as a rule, a pit will form in the middle of the glass sheet, which will have a bad effect on the stone that you are grinding. Therefore, the glass it is worth covering with thin plastic, which is used for covers when stitching sheets of A4 paper, then your glass will not change its shape, and the stone will be correctly aligned.
 
tommytman said:
Gritomatic also sells a Jende glass lapping plate with SiC powder for an ok price. Anyone ever use that? Lee valley also sells a glass plate, plastic film, and sic powder. Not sure which to get.

I ended up placing a 500 grit sand paper on the non grooved side of the Norton flattening stone. After a bit of work the surface was fixed. But I need a larger work surface than the Norton.

Anyone use the jende or the Lee valey glass plate?
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If you are using sandpaper, it doesn't have to be perfectly flat. A cheap large bathroom tile should be ideal. If it doesn't have texturing on the surface, you could also use that for SiC powder as well as long as it's reasonably flat.

You might be also able to find a cheap piece of glass or an offcut of granite or marble that is flat. There isn't really any need to get anything too expensive. Sometimes you see those small glasstop tables at second hand stores that could be ideal. Or ask around at a place that sells pieces of granite/marble for benchtops and see if they have any offcuts or broken pieces.
 
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