Naniwa SuperStone 8k gouge

[Kerneldrop]

I gouged an 8k stone with a knife tip, and it appears that the stone has a small low spot shaped like an oval.

I have an Atoma 140. Do I just lap until the gouges and low spot is gone...or just leave it all be?

Do I need to follow up with an 8k Nagura stone to smooth the finish left by the Atoma 140?

 

[UncleBoots]

Well, the stone could use some cleanup, so I'd certainly do some work with the Atoma to get a nice clean surface.

Whether you want to take it all the way down past the gouge depends on whether the gouge is in your way when sharpening, or whether it just bugs you.

I don't think you need to bother with the nagura afterwards, unless you're honing razors, or striving for a hair-whittling edge. There will be some surface roughness, but I wouldn't expect it to amount to much, or have much effect, unless you're doing something very demanding of a super-clean edge.

 

[KenHash]

I would hit it with the Atoma 140 and use the Nagura afterwards as an 8000 is mostly a polisher.
Can't tell the depth of the oval but I would work around it if possible until in time I'd flatten the whole thing.

 

[vlodko_lviv]

it would be worth having a set of silicon carbide powders as well as a sheet of glass. then the stone is easily and quickly leveled and brought to the required smoothness

 

[Diemaker]

I don't think a few small gouges will affect your sharpening so I personally wouldn't try to remove it. Besides Murphy's law dictates that if you remove it you will do it again, if it is there you are safe. I will second using loose abrasive on a flat plate to dress stones. In my experience 3 body abrasion is far superior to 2 body for this application for several reasons.

 

[Kerneldrop]

Thank y'all for the replies.

it would be worth having a set of silicon carbide powders as well as a sheet of glass. then the stone is easily and quickly leveled and brought to the required smoothness

What grits do you recommend?

Besides Murphy's law dictates that if you remove it you will do it again, if it is there you are safe. I will second using loose abrasive on a flat plate to dress stones. In my experience 3 body abrasion is far superior to 2 body for this application for several reasons.

Oh, I'll definitely do it again, haha....I don't have the speed or muscle memory yet. I'll read about the 3 body abrasion and implement that in my routine.

I don't think you need to bother with the nagura afterwards, unless you're honing razors, or striving for a hair-whittling edge. There will be some surface roughness, but I wouldn't expect it to amount to much, or have much effect, unless you're doing something very demanding of a super-clean edge.

I don't have the skills for hair-whittling so I'll leave it alone.

Can't tell the depth of the oval but I would work around it if possible until in time I'd flatten the whole thing.

That's what I'll do.

 

[Kerneldrop]

Now we have lapping closure
First time I’ve lapped a stone. It cleaned up pretty easily. My goal was just to barely clean it up but then I went all in. It happens
I see now what I’ve read about the marks left behind…I doubt it interferes with my sharpening. Lol

 

[vlodko_lviv]

What grits do you recommend?

120, 240, 400, 600, 800, 1200 FEPA-F
Now you have just leveled the stone, but its surface does not correspond to its hardness. Therefore, the sharpening result will not match your stone. Silicon carbide powders are needed for this. In the case of 8000 grit according to JIS, this is F1200 according to FEPA-F or 3 µm. For the correct operation of the stone, it is desirable to grind it on a powder twice as coarse as the grit of the stone. In your case, it should be F800 powder. But after ATOM, you need to use a few more intermediate powders, at least one of only 400. For final proofing, at the end, prove the stone on its own suspension

 

[chalby]

120, 240, 400, 600, 800, 1200 FEPA-F
Now you have just leveled the stone, but its surface does not correspond to its hardness. Therefore, the sharpening result will not match your stone. Silicon carbide powders are needed for this. In the case of 8000 grit according to JIS, this is F1200 according to FEPA-F or 3 µm. For the correct operation of the stone, it is desirable to grind it on a powder twice as coarse as the grit of the stone. In your case, it should be F800 powder. But after ATOM, you need to use a few more intermediate powders, at least one of only 400. For final proofing, at the end, prove the stone on its own suspension

You could achieve the same thing with a finer grit wet and dry sandpaper(or other methods). You don't need SiC powder.

 

[vlodko_lviv]

You could achieve the same thing with a finer grit wet and dry sandpaper(or other methods). You don't need SiC powder.

You can and so. But the quality of the surface will be higher when using powder. I mean the flatness of the surface. On the other hand, you can also make pits and humps on the powder. In addition, fixed grain when using sandpaper and free grain when using silicon carbide work differently.
To check the flatness, you need to use a straightedge.
All this is at the discretion of the user, I use it, someone does not use it. But theoretically it should be done like this

 

[chalby]

You can and so. But the quality of the surface will be higher when using powder. I mean the flatness of the surface. On the other hand, you can also make pits and humps on the powder. In addition, fixed grain when using sandpaper and free grain when using silicon carbide work differently.
To check the flatness, you need to use a straightedge.
All this is at the discretion of the user, I use it, someone does not use it. But theoretically it should be done like this

Do it the way you want, but the end result would be negligible. I think this is making something simple and over-complicating it.

 

[vlodko_lviv]

I think this is making something simple and over-complicating it.

Have you compared the results?
This is the case when 20% of the time gives 80% of the result and, accordingly, the remaining 80% of the time will give 20% of the result. On the other hand, if not, why use stones like Naniva 8000? In the photo after atom 140, the ditch is visible to the naked eye, and Naniva's grid is 3 μm. Does it compare normally?

 

[Kerneldrop]

On the other hand, you can also make pits and humps on the powder. In addition, fixed grain when using sandpaper and free grain when using silicon carbide work differently.
To check the flatness, you need to use a straightedge.

I'm trying to picture how this method is performed and how one gets accurate results with "free floating" SiC powder rolling around.

 

[vlodko_lviv]

I'm trying to picture how this method is performed and how one gets accurate results with "free floating" SiC powder rolling around.

you just try, and if you don't want to try, you can watch YouTube

 

[chalby]

Have you compared the results?
This is the case when 20% of the time gives 80% of the result and, accordingly, the remaining 80% of the time will give 20% of the result. On the other hand, if not, why use stones like Naniva 8000? In the photo after atom 140, the ditch is visible to the naked eye, and Naniva's grid is 3 μm. Does it compare normally?

I'm saying using a fine grit wet and dry will create a smooth surface. So will a good flattening stone that most stone manufacturers recommend.

You can argue about how much better it is to use exact SiC powder with exact stones but there are thousands of people out there who are getting great results who have never used SiC powder.

You seem to believe that there is only one way to do this. You do you. I believe that there are several ways.

 

[garry3]

I'm trying to picture how this method is performed and how one gets accurate results with "free floating" SiC powder rolling around.

Just depends on what tolerances an individual finds acceptable. I go from sic powder to wet dry paper on some stones for that reason.

 

[jeffbird]

The Naniwa 8k is a soft stone. A few minutes with an Atoma 140 or comparable DMT will have it flat with minimal time or mess. Also, Naniwa makes a nice hard flattening stone for about $25 that is quick and easy.

SiC powder is the wrong tool for this task.

 

[chalby]

The Naniwa 8k is a soft stone. A few minutes with an Atoma 140 or comparable DMT will have it flat with minimal time or mess. Also, Naniwa makes a nice hard flattening stone for about $25 that is quick and easy.

SiC powder is the wrong tool for this task.

Just my opinion but I wouldn't say it is the wrong tool. It works fine as do a number of other methods.

 

[Kerneldrop]

What exactly do I need to do to get it back to 8k factory smooth?

I do have the Naniwa flattening stone 10-1142 #220, and Sharp Pebble 120/320 flattening stone

 

[chalby]

What exactly do I need to do to get it back to 8k factory smooth?

I do have the Naniwa flattening stone 10-1142 #220, and Sharp Pebble 120/320 flattening stone

Have you tried either of those? I wouldn't overthink it. Try the Naniwa flattening stone and have a close look at the finish and see if it looks smooth.

I have a 8k stone(Kitayama) and flatten/dress it with the 400 Atoma or 1200 grit wet and dry on a flat tile or glass. Just wet both surfaces and do circular motions. It looks the same as new.