To practice flattening a finishing stone, I flattened a cheap chinese 12k using a 300/1000 diamond plate. I used the pencil grid method. The surface feels smooth to the touch, but there are a lot of scratches on the stone. Is this normal? Is it safe to flatten my Coticule and La Lune with the diamond plate? Should I also use 1200 wet/dry sandpaper?
Flattening a finishing stone
- Thread starter redwoolf
- Start date
Before trying that on your coticule take a knife or cleaver to the diamond plate and try to wear it down. Heck you can do it on a concrete sidewalk. Just try and get it worked in.
If it's leaving scratches like that I wouldn't. Once you get that 1k side broke in too the point it almost feels that it's done for the count and use a light, fast touch, you should be able to make short work of them. For softer stones like that is suggest a fine India stone, or even a barbers hone if you got one. I've also used porous arks to flatten softer stones and they'll work too, just a little slower but assuming yours are flat, you can really lean into them too and get the cheese grater effect and then slowly lighten pressure and add water periodically to dilute slurry(just like honing) and you'll have those stones appear glassy to the eye/ touch and buttery to your blade.
Yeah, raises hand, I am the idiot who scratched up all my stones with a 400/1000. Le oops, they still work. I may have to rethink this with a $$$ coticule though...
Scratched stones can be fixed easily, cheaply, just how I told you, and if you don't have those stones around tell me what you've got a far as rocks/ tools/ abrasives and I'll try to help though there are MUCH MUCH more knowledgeable men in the community who are around. Lots have been lost over the years but there is an insane amount of info I've found. I've searched all the sharpening site online and sometimes it looks like B&B is colonizing the internet and bringing a lost art back. Love it. Today my little brother(30) showed my son his "sharpener". It was akin to a tru-sharp(?) Set up but with a fixed frame. My 8 year old told him "my dad's going to make fun of you" and my brother replied "yep, you're right he's going to make fun of me." And I obliged. He buys disposable blades for his skinning knife. I sharpened everyone's knives at a crawfish boil we put on Saturday. Kids nuts, I tried to give him rocks....
Edited for typos: I'm buzzed lads,I apologize. Buried my Oma today.
Chinese “12K” are hard, some Ark hard though most are not 12k… They will ruin, rip out diamonds from a plate. Use loose 60 grit silicone carbide to flatten a Chinese stone. Once flat run it up to 600 grit.
Also, chances are you stone is not flat. 60 grit is light years from 300 grit. You can test this by making a grid with a sharpie on you Chinese and lapping it on a sheet of 220 wet and dry with a little bit of water on a steel cookie sheet on a flat cement floor. 220 will not flatten a Chinese but will tell you if it is flat. You can get a progression of 60-500 grit from Got Grit.com for about $15.
If the entire grid is not removed in less than 10 laps, it is not flat and the slurry just washed off the pencil grid.
The point of flatting a hard stone is to remove any rough pockets, so the stone face is smooth and an even grit, this is or should be a finish stone. You can not tell by touching the stone surface if it is flat or smooth.
If your Diamond plate is scratching, it is a high diamond or swarf build up. It should be flat after use on a Chinese stone, but a large kitchen knife will quickly tell you with an edge leading stroke and remove any high diamonds.
Make a paste of Bar Keepers Friend on you plate and let it sit for about 15 minutes, then scrub with a stiff brush, I use a fingernail brush. Barkeepers will remove all the swarf trapped in the diamonds and revive a diamond plate. I give my plates a treatment every 3-4 month to keep them cutting fast. Once the diamonds are ripped out, they are gone, but most plates will still cut and you can use the whole plate, usually the ends are in good shape.
Light scratches in a stone do not affect the edge unless they are parallel to the edge, rare. For soft stones like coticules that self slurry it does not matter.
A good Chinese will laugh at 1200 W&D unless you run through a progression. Once a hard stone is flat, you can run up the grit quickly, (getting to flat is the trick), just remove the previous grits scratches, large jumps don’t work. Finish one side to 600 the other to 1k.
Also, chances are you stone is not flat. 60 grit is light years from 300 grit. You can test this by making a grid with a sharpie on you Chinese and lapping it on a sheet of 220 wet and dry with a little bit of water on a steel cookie sheet on a flat cement floor. 220 will not flatten a Chinese but will tell you if it is flat. You can get a progression of 60-500 grit from Got Grit.com for about $15.
If the entire grid is not removed in less than 10 laps, it is not flat and the slurry just washed off the pencil grid.
The point of flatting a hard stone is to remove any rough pockets, so the stone face is smooth and an even grit, this is or should be a finish stone. You can not tell by touching the stone surface if it is flat or smooth.
If your Diamond plate is scratching, it is a high diamond or swarf build up. It should be flat after use on a Chinese stone, but a large kitchen knife will quickly tell you with an edge leading stroke and remove any high diamonds.
Make a paste of Bar Keepers Friend on you plate and let it sit for about 15 minutes, then scrub with a stiff brush, I use a fingernail brush. Barkeepers will remove all the swarf trapped in the diamonds and revive a diamond plate. I give my plates a treatment every 3-4 month to keep them cutting fast. Once the diamonds are ripped out, they are gone, but most plates will still cut and you can use the whole plate, usually the ends are in good shape.
Light scratches in a stone do not affect the edge unless they are parallel to the edge, rare. For soft stones like coticules that self slurry it does not matter.
A good Chinese will laugh at 1200 W&D unless you run through a progression. Once a hard stone is flat, you can run up the grit quickly, (getting to flat is the trick), just remove the previous grits scratches, large jumps don’t work. Finish one side to 600 the other to 1k.
Your instincts seem correct here -- those scratches are not right. Never seen anything like that.
@Wid is no doubt correct that it's "new diamond plate syndrome." Before I got my NL-10, I used some diamond plates that were worn to uselessness for any metal-grinding task. I had almost thrown them away. But they worked great for stone-flattening.
@Wid is no doubt correct that it's "new diamond plate syndrome." Before I got my NL-10, I used some diamond plates that were worn to uselessness for any metal-grinding task. I had almost thrown them away. But they worked great for stone-flattening.
- Thread starter
- #8
I was instructed to use 400, 600, 800, then 1000 grit wet/dry sandpaper in the sink under running water with the sandpaper on a floor tile or appropriate (perfectly flat) surface. I used oscillating motions and lifted the stone frequently to allow any slurry created to be rinsed away. You know you're ready for the next paper in the progression when the stone "sticks" to the paper.
Take your time and let the paper do its work.
Worked a charm.
Take your time and let the paper do its work.
Worked a charm.
- Thread starter
- #10
Thanks for this. I have the wet dry sandpaper also, just need to get a stone floor tile.
I’ve actually started leveling my natural stones with the gently broken and soft Arkansas stone. I’ve been meaning to try the soft Arkansas Stone for generating base stone slurry on a JNat but I just haven’t gotten around to it yet. But to me the diamond plates are the way to go for synthetics.
The old calico, pink, or purple soft arks/nu-washitas that are super friable are amazing for this because thrills start to slurry with pressure and really speed things up. I've used them to make slurries on hard Arks for knife sharpening to speed things up. The slurry seems to break down to me which I'dattribute to how friable they are.
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“I was instructed to use 400, 600, 800, then 1000 grit wet/dry sandpaper in the sink under running water with the sandpaper on a floor tile or appropriate (perfectly flat) surface.
Worked a charm.”
For an Ark or Chinese? A waterstone maybe, but you will not get a hard stone flat with 400 grit wet & dry.
60 grit wet and dry does not perfume like 60 grit loose Silicone Carbide. It could get you flat, but will burn through a lot of paper, time and arm muscle.
A steel cookie sheet contains the mess and remains flat, and there is a mess.
Worked a charm.”
For an Ark or Chinese? A waterstone maybe, but you will not get a hard stone flat with 400 grit wet & dry.
60 grit wet and dry does not perfume like 60 grit loose Silicone Carbide. It could get you flat, but will burn through a lot of paper, time and arm muscle.
A steel cookie sheet contains the mess and remains flat, and there is a mess.
It was a JNAT.
You can use a peice of thick glass, if you have one handy. For a Cnat start with about 220 grit and go up 1000.
- Thread starter
- #16
I ended up laying the wet dry on the diamond plate and using that to lap my stones and I think I got good results. Thanks for all the advice.
- Thread starter
- #17
Yikes! The translucent ark is very porous and hard. I used sharpie on it to make a grid before flattening it and it took forever for it to disappear. Still was finally able to get it lapped to 1200 with wet dry.
But you did it. With patience we can do everything. Good job!
Loose polishing powder will give a much more even finish. I’ve never been able to flatten with a stone using a plate without leaving marks. Honestly the difference is amazing.
I want to give an update to my above post above. I had failed to mark my stones initially before flattening and the excessive scratching was because they were convex and the diamond was just trying to do it's job. I stopped early do to the amount coming off.
This past weekend I decided it's only money so I marked the stones and commenced to grinding them down the sink. Well, now I know how a properly flattened stone is supposed to feel! I used the 400 side only and don't see any reason to use the 1000 on anything other than my finishing stone. I haven't done it yet, but I did manage to erase the scratches with the slurry stone.
My only question is whether I need anything other than this 400/1000 cheapie, other than for Arks of course?
This past weekend I decided it's only money so I marked the stones and commenced to grinding them down the sink. Well, now I know how a properly flattened stone is supposed to feel! I used the 400 side only and don't see any reason to use the 1000 on anything other than my finishing stone. I haven't done it yet, but I did manage to erase the scratches with the slurry stone.
My only question is whether I need anything other than this 400/1000 cheapie, other than for Arks of course?
