Separate flattening stone and course stone, or can one stone do double duty?

[nexus1935]

I currently have a Chosera 800 and a Shapton Glass 3000 stone, and I need something to flatten them now. I've read in the forums that diamond stones are good choices for flattening (Atoma and DMT seem popular), but these can also be used for sharpening as they're 140 / 220 / 400 grit surfaces. I'm also thinking about a course stone, more for experimenting/experience, fixing and thinning some old knives just for learning.

So my question is - can diamond plates actually serve as double duty for flattening and sharpening? It looks like those diamond stones are actually sheets surfaced on a backing, so I'm worried about wearing those down and needing to replace (and they're expensive!). Would I better off buying something specific for flattening, and then a separate course stone to practice on and wear down?

Thanks!

 

[kayman67]

Anything will eventually wear out. How fast would depend on what's required of them to perform.
All my diamond stones were used for flattening as well. All still cut. Some have a few years by now. I flatten softer stones, but also difficult stones (sintered ceramics, arkansas and so on).
I am going to replace my Atoma 140 with a coarser Nanohone.

 

[M1k3]

3 stone/3 plate method works. Flattening plates work faster, until you wear away the diamonds, and stay flat. Flattening stones work also. But need to be periodically flattened. Unless you use the 3 stone method with it.

 

[Bobby2shots]

I currently have a Chosera 800 and a Shapton Glass 3000 stone, and I need something to flatten them now. I've read in the forums that diamond stones are good choices for flattening (Atoma and DMT seem popular), but these can also be used for sharpening as they're 140 / 220 / 400 grit surfaces. I'm also thinking about a course stone, more for experimenting/experience, fixing and thinning some old knives just for learning.

So my question is - can diamond plates actually serve as double duty for flattening and sharpening? It looks like those diamond stones are actually sheets surfaced on a backing, so I'm worried about wearing those down and needing to replace (and they're expensive!). Would I better off buying something specific for flattening, and then a separate course stone to practice on and wear down?

Thanks!

I would imagine that a Shapton Pro 120 or 220 would be a good choice, and at the same time you could order a small bag of 60 grit SiC powder. Get yourself a ceramic floor-tile or a piece of plate-glass, and you should be good to go for roughly $75.

 

[rickbern]

I currently have a Chosera 800 and a Shapton Glass 3000 stone, and I need something to flatten them now. I've read in the forums that diamond stones are good choices for flattening (Atoma and DMT seem popular), but these can also be used for sharpening as they're 140 / 220 / 400 grit surfaces. I'm also thinking about a course stone, more for experimenting/experience, fixing and thinning some old knives just for learning.

So my question is - can diamond plates actually serve as double duty for flattening and sharpening? It looks like those diamond stones are actually sheets surfaced on a backing, so I'm worried about wearing those down and needing to replace (and they're expensive!). Would I better off buying something specific for flattening, and then a separate course stone to practice on and wear down?

Thanks!

I’ve never used a plate but I’ve heard you get deep scratches from them. 220-250 grit stones are often pretty cheap.

https://www.korin.com/knife-accessories/sharpening-stone-brands/stone-brands-suntiger

 

[SeattleBen]

I let my atoma 140 do double duty as a plate and stone for soft German style beaters that I get from others. Not having to flatten a coarse stone so often and really getting after a beat up knife makes my life much easier.

 

[rickbern]

I guess I could have been clearer for the ops question.

get two separate things. The difference between this 220 and any 400 is very large. The stones are not interchangeable easily. The 400 sets bevels, the 220 thins.

 

[nexus1935]

I let my atoma 140 do double duty as a plate and stone for soft German style beaters that I get from others. Not having to flatten a coarse stone so often and really getting after a beat up knife makes my life much easier.

This was exactly what I was wondering - great to hear someone has done this before!

 

[nexus1935]

I guess I could have been clearer for the ops question.

get two separate things. The difference between this 220 and any 400 is very large. The stones are not interchangeable easily. The 400 sets bevels, the 220 thins.

Would something like a Shapton Glass 320 straddle those two grit levels and do both? Or is an Atoma 400 effective at flattening? That would allow me to just get a single additional stone

 

[nexus1935]

I would imagine that a Shapton Pro 120 or 220 would be a good choice, and at the same time you could order a small bag of 60 grit SiC powder. Get yourself a ceramic floor-tile or a piece of plate-glass, and you should be good to go for roughly $75.

Do you just put the powder on the tile and glass and rub the stone on top then? No need to fix/adhere the powder? This is my first time hearing this method.

 

[SeattleBen]

Do you just put the powder on the tile and glass and rub the stone on top then? No need to fix/adhere the powder? This is my first time hearing this method.

Wet the powder and the answer is yes.

I also have the SP320 and I don't hate it but when I am dealing with something that's really trashed I'm always glad, and increasingly eager, to just get to business with the Atoma. It sounds awful and feels worse but you'll save so much time and nobody who's handing you their Bed Bath and Beyond Henckle will beef with you about scratch pattern. Just make sure to fully deburr and you're off to the races.

 

[rickbern]

Would something like a Shapton Glass 320 straddle those two grit levels and do both? Or is an Atoma 400 effective at flattening? That would allow me to just get a single additional stone

I have the 220 I linked to and a jns 300. Completely different class of stone, if I was seriously thinning a knife I wouldn’t want to only have the 300 available. Differences in this range are larger than the numbers suggest.

 

[nexus1935]

I have the 220 I linked to and a jns 300. Completely different class of stone, if I was seriously thinning a knife I wouldn’t want to only have the 300 available. Differences in this range are larger than the numbers suggest.

For that SunTiger 220, do you then need another stone to flatten it over time? The one reason I thought about diamond plates is that I don't need another flattening device to flatten my flattening device (which I have read on regular flattening stones).

Good point on the actual abrasion difference at low grit levels. My only experience with coarse stones is a ~$15 random 400/1000 combo stone that I bought off Amazon as my cheap entry to sharpening, and I just flattened that on the sidewalk. Now that I have a couple proper stones, I'm willing to buy something to flatten but still want to limit the investment for now.

 

[Bobby2shots]

Do you just put the powder on the tile and glass and rub the stone on top then? No need to fix/adhere the powder? This is my first time hearing this method.

Yes,,, sprinkle 1/2 teaspoon of SiC powder on the glass plate,,, add a sprinkle of water, then rub the stone on the compound without pushing down on the stone. Just guide the stone with your fingers. You can do any pattern you want,,,, figure 8,,, or circles,,,, or, back and forth,,, whatever is comfortable for you.

Like this guy,,,

 

[rickbern]

For that SunTiger 220, do you then need another stone to flatten it over time? The one reason I thought about diamond plates is that I don't need another flattening device to flatten my flattening device (which I have read on regular flattening stones).

Good point on the actual abrasion difference at low grit levels. My only experience with coarse stones is a ~$15 random 400/1000 combo stone that I bought off Amazon as my cheap entry to sharpening, and I just flattened that on the sidewalk. Now that I have a couple proper stones, I'm willing to buy something to flatten but still want to limit the investment for now.

Yes. I have an atoma plate as well

 

[Karl_in_Chicago]

Yes,,, sprinkle 1/2 teaspoon of SiC powder on the glass plate,,, add a sprinkle of water, then rub the stone on the compound without pushing down on the stone. Just guide the stone with your fingers. You can do any pattern you want,,,, figure 8,,, or circles,,,, or, back and forth,,, whatever is comfortable for you.

Like this guy,,,

Wow, talk about a picture (or in this case video) being worth a thousand words. That explained everything about this, thanks for the link.

 

[nexus1935]

Yes,,, sprinkle 1/2 teaspoon of SiC powder on the glass plate,,, add a sprinkle of water, then rub the stone on the compound without pushing down on the stone. Just guide the stone with your fingers. You can do any pattern you want,,,, figure 8,,, or circles,,,, or, back and forth,,, whatever is comfortable for you.

Like this guy,,,

That was a super helpful video, thanks for posting @Bobby2shots !

 

[Nemo]

Yes,,, sprinkle 1/2 teaspoon of SiC powder on the glass plate,,, add a sprinkle of water, then rub the stone on the compound without pushing down on the stone. Just guide the stone with your fingers. You can do any pattern you want,,,, figure 8,,, or circles,,,, or, back and forth,,, whatever is comfortable for you.

Like this guy,,,

The SiC grit on a glass plate does work.... however, there is a risk of contaminating your stone with loose SiC grit (especially for soft stones). Also a,risk of scratching up your sink if you are using coarse SiC in the sink. The risk is probably lower if you use wet and dry sandpaper instead.

Or you could just make your life easy and get a diamond plate...

 

[kayman67]

In absolute terms, a maintenance routine done often on glass, has some problems.
You need a very large glass surface because some glass is also removed while doing this. With smaller pieces I've seen that flatness problems appear quite fast.
The used powder and muddy water should not be put into the sink as they tend to get it clogged. There were many reports regarding this.

 

[Bobby2shots]

That was a super helpful video, thanks for posting @Bobby2shots !

My pleasure Nexus 1935,,, and thanks to Jef Jewell for posting that on Youtube. He's the best,,, and always spot on. His work is meticulous, and he obviously takes great pride in what he does. He tells it like it is, and no wasted words. I love watching him work.

 

[Bobby2shots]

Wow, talk about a picture (or in this case video) being worth a thousand words. That explained everything about this, thanks for the link.

My pleasure Karl, Jef's sharpening videos are great. Check out his other videos too; he's a superb instructor and communicator. He seems to have a gift for anticipating questions before they're even asked, and his answers are always accurate and well thought out. I find it very relaxing to just watch and listen to him work.

 

[Bobby2shots]

The used powder and muddy water should not be put into the sink as they tend to get it clogged. There were many reports regarding this.

Yes, you really don't want to be throwing that stuff down the drain, Rinse the plate in a bucket, or take it outside and rinse it with water. If you MUST use the sink, place a rag over the drain; that will allow the water to filter through the rag, leaving the sediment behind. When you're done, use that rag to wipe the sink. You really don't need to be flattening at the sink anyway. A small bottle and a bit of water is all that's required. Go sit on the porch, or the back yard,,,Have a brew.

If you're in a high-rise,,, throw it over the balcony railing, and yell as loudly as you can "Don't Look Up" !!!

 

[Bobby2shots]

The SiC grit on a glass plate does work.... however, there is a risk of contaminating your stone with loose SiC grit (especially for soft stones). Also a,risk of scratching up your sink if you are using coarse SiC in the sink. The risk is probably lower if you use wet and dry sandpaper instead.

Or you could just make your life easy and get a diamond plate...

The SiC grit is just so much cheaper though, especially if you're comparing it with a quality diamond plate with monocrystalline diamonds electro-bonded to the plate. I think the diamond plates are great for flattening,, but I'm not so sure that they condition the surface of harder, low-friability stones as well as the SiC powders. I might be wrong about that,,, time will tell.

 

[Nemo]

The SiC grit is just so much cheaper though, especially if you're comparing it with a quality diamond plate with monocrystalline diamonds electro-bonded to the plate. I think the diamond plates are great for flattening,, but I'm not so sure that they condition the surface of harder, low-friability stones as well as the SiC powders. I might be wrong about that,,, time will tell.

I suspect that it's probably not a lot cheaper than W&D sandpaper.

And the first time you spend 2 hours in a sanding progression to get rid of 80 grit SiC scratches on your stone which became contaminated without you realising, you'll probably wish you'd gone a different route. Just sayin'

 

[Bobby2shots]

I suspect that it's probably not a lot cheaper than W&D sandpaper.

And the first time you spend 2 hours in a sanding progression to get rid of 80 grit SiC scratches on your stone which became contaminated without you realising, you'll probably wish you'd gone a different route. Just sayin'

I agree about the W&D sandpaper. I've worked with it in my shop. I used it to flatten the soles of some of my older handplanes.. Mind you, that stuff will release grit too. Regardless of which route you choose, I suppose it should be required procedure that you carefully feel each stones' surface after flattening/conditioning, to ensure there are no contaminants, even with some of the inexpensive diamond plates that use polycrystalline diamonds. With ANY abrasive for that matter.

 

[kayman67]

The SiC grit is just so much cheaper though, especially if you're comparing it with a quality diamond plate with monocrystalline diamonds electro-bonded to the plate. I think the diamond plates are great for flattening,, but I'm not so sure that they condition the surface of harder, low-friability stones as well as the SiC powders. I might be wrong about that,,, time will tell.

Diamond plates work, but it's way faster with powders. It's hard to put a number on it, but something like 1:20 ratio with very demanding stones, is what I would call a good estimate. The difference is really huge.
A 2k diamond plate will make a translucent be mirror like. So would a very fine SiC stone (above 2k). Used them both.