flattening coarse stones?

[Choppin]

I currently use a glass plate and loose SiC (#60 I think) to flatten my SG220 and Debado 180, but I'm looking for a more practical solution.

Naniwa and Suehiro make some really coarse flattening stones (100 grit and lower), has anyone tried them? I guess with time you'll need to flatten them as well.

https://hitohira-japan.com/products/laeac-010-60
https://hitohira-japan.com/products/laeac-010-24
https://www.japaneseknifeimports.com/collections/sharpening-accessories/products/stone-fixer-100
https://www.japaneseknifeimports.co...ucts/gesshin-extra-large-stone-fixer-100-grit

 

[OkayMode]

I have one of the Naniwa ones and I’m pretty unimpressed by it. It’s very slow.

Will an Atoma not work?

 

[Krouton]

I have one of the Naniwa ones and I’m pretty unimpressed by it. It’s very slow.

Will an Atoma not work?

Also not a fan of the naniwa and I use an Atoma #140 now. Not sure how well that will work on the 180 stone though.

 

[sansho]

switch to diamond stones? lol

 

[Rangen]

I had a giant coarse flattening stone of this type, long ago. I remember using it to try to flatten a Shapton Glass stone that was way out of flat. It seemed to be going very slowly. Then I pulled out a diamond plate. Whoa. I tossed the big, coarse flattening stone, because I couldn't imagine why I would ever use it, when the diamond plate was so much faster.

 

[ethompson]

Depending on how much material you need to remove, a flat wet sidewalk will make progress in a hurry. Just keep things wet. Coarse SIC and glass slower but more precise and still faster than Atoma 140. Again, lots of water to avoid silicosis. Final dressings with Atoma 140.

 

[HumbleHomeCook]

So maybe this leads to the first question of, how flat does a coarse stone need to be?

 

[ethompson]

So maybe this leads to the first question of, how flat does a coarse stone need to be?

Depends on what you’re trying to accomplish. Really crisp shinogi on a wide bevel KU or complex single bevel work? Really flat is good. General thinning or most other stuff? Not that flat.

Hard and flat coarse stones are the key to crispy transitions and not wording KU (well than and not rolling the shoulder)

 

[Heckel7302]

I use a cheap coarse diamond pad from Amazon to get the bulk down, then rub on a concrete paver to get all the way flat.

 

[Choppin]

@Ok__mode_6953 @Krouton I used my JKI diamond flattening plate (similar to an Aroma 140) when I went through my first SG220. It does the job fairly well, but my plate is now significantly slower than it used to be, so I reserve it to stones #500 and finer.

@sansho yeah a NSK 200 is in the plans... just no $ now

@HumbleHomeCook @ethompson that's a valid point... I have a bunch of monosteel knives to work on (vintage Sabs and Masakane), mostly reprofiling and thinning. I guess I'll dedicate my Debato to them and not worry too much about flattening, just try to use the whole stone surface evenly. And leave the SG220 for wide bevels and such, flattening more often.

I guess I'll keep using the glass plate for now and try to grab a NSK 200 soon!

 

[OkayMode]

I for one will be out on the street tonight with a chisel to get hold of some prime grade pavement...

Accepting pre orders now, get them before I slap a Japanese stamp on them and post on BST.

 

[ethompson]

I for one will be out on the street tonight with a chisel to get hold of some prime grade pavement...

Accepting pre orders now, get them before I slap a Japanese stamp on them and post on BST.

you wouldn't be the first lol, I've seen concrete with a Maruka stamp on the auctions before...

 

[labor of love]

Atoma 140 runs for $55 and the replacement strips without plate are $49 at Amazon. I remember a few years ago when it was normal to pick them up for $75-80.
I don’t know how cheap your other options are but this feels like a good deal.
Honestly I use my SG220 for stone flattening often because I’m not too crazy about it for thinning and won’t miss it when it’s gone.

 

[OkayMode]

you wouldn't be the first lol, I've seen concrete with a Maruka stamp on the auctions before...

‘Requires high skill and patience to refine the slurry’

 

[Choppin]

Atoma 140 runs for $55 and the replacement strips without plate are $49 at Amazon. I remember a few years ago when it was normal to pick them up for $75-80.
I don’t know how cheap your other options are but this feels like a good deal.

I might bite the bullet and do that. Glass + SiC works well but its messy, I get SiC everywhere and have to wash everything carefully to avoid grit contamination.

 

[HumbleHomeCook]

Have you ever considered trying a Norton Crystolon for coarse work?

 

[Chasingsharpness]

With coarse stuff I try to use the entire stone as much as I can. When I do have to inevitably flatten, I find anything other than coarse (60 grit) SiC is too slow. I since have invested in the SiC setup with a container and granite plate sized to fit inside to make the process faster and less messy.

 

[tostadas]

I drag my garden hose out to the sidewalk and do the bulk of the work. Then use 60grit SIC powder on a piece of tile to clean it up at the end.

 

[ReiHamono]

This will be a faster clean less expensive solution, until you switch to NSK

https://byxco.com/products/byxco-manticore-bench-stone

 

[HumbleHomeCook]

This will be a faster clean less expensive solution, until you switch to NSK

https://byxco.com/products/byxco-manticore-bench-stone

The Manticore is a different beast. It requires a lot of pressure to work and can be tough to get started.

 

[ReiHamono]

I use it to flatten my Gritomatic 120

Try using it as a flattening stone instead

 

[Choppin]

Have you ever considered trying a Norton Crystolon for coarse work?

not yet, but it’s in my plans.

I guess it’s super dense and rarely needs flattening?

 

[HumbleHomeCook]

not yet, but it’s in my plans.

I guess it’s super dense and rarely needs flattening?

Yes. I use oil for that kind of work and they can load up a bit but some hard pressure and/or some soap and water usually gets them working again.

 

[M1k3]

@Ok__mode_6953 @Krouton I used my JKI diamond flattening plate (similar to an Aroma 140) when I went through my first SG220. It does the job fairly well, but my plate is now significantly slower than it used to be, so I reserve it to stones #500 and finer.

@sansho yeah a NSK 200 is in the plans... just no $ now

@HumbleHomeCook @ethompson that's a valid point... I have a bunch of monosteel knives to work on (vintage Sabs and Masakane), mostly reprofiling and thinning. I guess I'll dedicate my Debato to them and not worry too much about flattening, just try to use the whole stone surface evenly. And leave the SG220 for wide bevels and such, flattening more often.

I guess I'll keep using the glass plate for now and try to grab a NSK 200 soon!

For mono steel knives, I'd recommend a Norton Crystolon or Sigma 240.

 

[Dr. Knives]

I’m testing some #60 resinoid diamond flatteners. see how those are

 

[Choppin]

For mono steel knives, I'd recommend a Norton Crystolon or Sigma 240.

want to try those. curiously the only steel that managed to seriously clog my SG220 was vintage Sabatier carbon.

 

[labor of love]

I’m down to maybe 7mm or so left on my third sigma 240, and will be buying a fourth one soon.

 

[Pie]

want to try those. curiously the only steel that managed to seriously clog my SG220 was vintage Sabatier carbon.

I can vouch for the Norton. A little narrow but it absolutely crushes soft steel. Zero dish when exposed to the same abuse as SP120 or SG220. I’ve given up keeping those dead flat or well conditioned, just refresh every other pass/use the whole stone and hope for the best. I might be using the wrong sic, and my glass plate is now dished.

Im considering using Norton for heavy removal, just the oil part gets me.

 

[M1k3]

I can vouch for the Norton. A little narrow but it absolutely crushes soft steel. Zero dish when exposed to the same abuse as SP120 or SG220. I’ve given up keeping those dead flat or well conditioned, just refresh every other pass/use the whole stone and hope for the best. I might be using the wrong sic, and my glass plate is now dished.

Im considering using Norton for heavy removal, just the oil part gets me.

You don't need very much oil. Just a few drops to lubricate the surface. It doesn't need to be flooded with oil.

 

[HumbleHomeCook]

I can vouch for the Norton. A little narrow but it absolutely crushes soft steel. Zero dish when exposed to the same abuse as SP120 or SG220. I’ve given up keeping those dead flat or well conditioned, just refresh every other pass/use the whole stone and hope for the best. I might be using the wrong sic, and my glass plate is now dished.

Im considering using Norton for heavy removal, just the oil part gets me.

@M1k3 is correct. Pour a little on and rub it in. I often let it sit for a few but not required. Wipe off excess if you want. Then use a little more to clean the stone.

I will sometimes use more oil depending on how it's performing but it is situational.

For coarse stones I just use laxative-grade mineral oil. I do that cuz it's cheap but it's also a lot thicker than dedicated honing oil. You might be surprised at the difference. So by using honing oil you can further promote the soaking in.