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Flattening a finishing stone

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?
Keep those worn out plates though because they can still be very useful, especially a 1k that's eaten half a dozen hard arks. It buffs soft stone wonderfully.
 
One of the guys at SharpeningSupplies.com just told me natural stones like Arks and Slates aren't meant to be lapped and doing so can change how they cut. That counters the advice given here and elsewhere. What gives? Did I ruin my La Lune, Black Shadow, and Translucent Ark by lapping them with sandpaper?
 
One of the guys at SharpeningSupplies.com just told me natural stones like Arks and Slates aren't meant to be lapped and doing so can change how they cut. That counters the advice given here and elsewhere. What gives? Did I ruin my La Lune, Black Shadow, and Translucent Ark by lapping them with sandpaper?
Short answer, yes, it will change how they cut; no you didn't ruin anything.

Long answer. There's lapping, and then there's dressing. Lapping, to me, is getting a stone flat. With a hard ark, that's something you do once. I don't have a ton of experience with slates but I think they stay flat pretty well compared to a synth that you might need to lap flat every time you use it, or at least every so often.

Dressing is different. With a finisher grade ark, for instance, if you dress it with 400 grit w/d it will perform a lot differently than if you dress it with 1200 w/d. Regardless, you probably want to hit it with a knife or a chisel for 30-50 laps to burnish off any high spots. If you don't, you'll feel it when you put a razor on it, and you probably won't like the results. I'm not sure what guys are using on La Lunes or Black Shadows, hopefully others will chime in. I have a slate-like stone that I finished to 600 w/d and that seems to work. Other folks might use another stone to dress the surface the way they like. Probably comes down to experimenting and personal preference.

The other thing, with an ark, is that it will burnish more and more over time as you hone on it. Some guys prefer that. I don't really, I hit mine with 800 or 1000 w/d whenever it starts to get too shiny and slow and then lightly burnish it with a beater razor or a knife. That's my sweet spot, I'm sure others have their own preferences.
 
One of the guys at SharpeningSupplies.com just told me natural stones like Arks and Slates aren't meant to be lapped and doing so can change how they cut. That counters the advice given here and elsewhere. What gives? Did I ruin my La Lune, Black Shadow, and Translucent Ark by lapping them with sandpaper?
Different finishes on arks allow them to cut differently. A translucent finished on 400# will be faster than one finished on 1k then burnished. The burnished one will give a finer edge but take longer. You didn't ruin your stones, they were lapped to get flat in the first place! What grit did you finish them on? I don't have a black shadow but I've lapped almost every ark and la lune I own and they work great for me. I will note that I don't burnish any stone except through use BUT I sharpen a whole lot more than just razors so just about any stone will get a knife on it before it sees a razor through my regular use.
 
Short answer, yes, it will change how they cut; no you didn't ruin anything.

Long answer. There's lapping, and then there's dressing. Lapping, to me, is getting a stone flat. With a hard ark, that's something you do once. I don't have a ton of experience with slates but I think they stay flat pretty well compared to a synth that you might need to lap flat every time you use it, or at least every so often.

Dressing is different. With a finisher grade ark, for instance, if you dress it with 400 grit w/d it will perform a lot differently than if you dress it with 1200 w/d. Regardless, you probably want to hit it with a knife or a chisel for 30-50 laps to burnish off any high spots. If you don't, you'll feel it when you put a razor on it, and you probably won't like the results. I'm not sure what guys are using on La Lunes or Black Shadows, hopefully others will chime in. I have a slate-like stone that I finished to 600 w/d and that seems to work. Other folks might use another stone to dress the surface the way they like. Probably comes down to experimenting and personal preference.

The other thing, with an ark, is that it will burnish more and more over time as you hone on it. Some guys prefer that. I don't really, I hit mine with 800 or 1000 w/d whenever it starts to get too shiny and slow and then lightly burnish it with a beater razor or a knife. That's my sweet spot, I'm sure others have their own preferences.
On my la lunes I used a worn out 1k then used it like a slurry stone to build up slurry on my big ark to condition the surface of la lune, followed by repeated slurries with the slurry stone it came with.
 
One of the guys at SharpeningSupplies.com just told me natural stones like Arks and Slates aren't meant to be lapped and doing so can change how they cut. That counters the advice given here and elsewhere. What gives? Did I ruin my La Lune, Black Shadow, and Translucent Ark by lapping them with sandpaper?
Sometimes if you lap through a layer of a slate that's kind of variable the stone can get better or worse but I know my la lunes are insanely homogenous.
 
Different finishes on arks allow them to cut differently. A translucent finished on 400# will be faster than one finished on 1k then burnished. The burnished one will give a finer edge but take longer. You didn't ruin your stones, they were lapped to get flat in the first place! What grit did you finish them on? I don't have a black shadow but I've lapped almost every ark and la lune I own and they work great for me. I will note that I don't burnish any stone except through use BUT I sharpen a whole lot more than just razors so just about any stone will get a knife on it before it sees a razor through my regular use.
I used #400 then finished with #1000.
 
I used #400 then finished with #1000.
Should be just fine, my personal favorite(thanks to dans) is #600 but if you finish one side to 400# and one to 1k# you will have a faster side for prefinishers(400) and the 1k for finishing/ polishing. Use the 1k side to condition your slates and you should be golden friend.
 
I use a 1200 grit atoma to flatten my cotis. Yeah they leave some scratches but by the time the bevel is set and the dilutions are done they are almost all gone.
 
I use a 1200 grit atoma to flatten my cotis. Yeah they leave some scratches but by the time the bevel is set and the dilutions are done they are almost all gone.
I usually use a coticule slurry stone or pocket ark to buff them out but imo, on coticules, a bbw that's almost the same hardness as the coticule conditions the surface to a smoothness hard to match. If you do that and use a slurry stone that's soft and fine I've found I can pull a much sharper edge out of them than otherwise. Diamonds are harder than garnets so they cut slices in the garnets and make them rougher and sharper. The bbw garnets are the same hardness but bigger and smoother so they can smooth it out. I can see your method being a pretty ingenious way to utilize those more aggressive garnets for setting a bevel more quickly and the slurrying releases them and they're washed away eventually. I'm going to try this next time I have to flatten a coticule. I think using a slurry stone that's harder than the base stone would be the only way to effectively do this without having done Ransome garnets in the coticule. A les lat slurry stone would be ideal for this. I use the hybrid side on a les lat slurry stone to slurry my thuringians if it's close at hand and my la lune slurry stone is put up. Works great.
 
“One of the guys at SharpeningSupplies.com just told me natural stones like Arks and Slates aren't meant to be lapped and doing so can change how they cut. That counters the advice given here and elsewhere. What gives? Did I ruin my La Lune, One of the guys at SharpeningSupplies.com just told me natural stones like Arks and Slates aren't meant to be lapped and doing so can change how they cut. That counters the advice given here and elsewhere. What gives? Did I ruin my La Lune, Black Shadow, and Translucent Ark by lapping them with sandpaper?, and Translucent Ark by lapping them with sandpaper?”

So, ask the guy how many Straight Razors he hone a year, and how are the shaves?

His answer will tell you all you need to know.
 
I used #400 then finished with #1000.
You can chop and change as much as you like. Don’t like how the 1000 cuts? Just lap it again on the 400. Want to try 600? Grab a sheet of 600 and have at it. As said before, it is just personal preference, and you should try a few finishes to decide what you like.

Anybody telling you that lapping ruins the hone should be ignored. Do they think they came out of the ground in a nice rectangle?
 
One of the guys at SharpeningSupplies.com just told me natural stones like Arks and Slates aren't meant to be lapped and doing so can change how they cut. That counters the advice given here and elsewhere. What gives? Did I ruin my La Lune, Black Shadow, and Translucent Ark by lapping them with sandpaper?
You just ruined your stones. You better send them to me. I will dispose of them in a environmentally friendly way:)
 
One of the guys at SharpeningSupplies.com just told me natural stones like Arks and Slates aren't meant to be lapped and doing so can change how they cut. That counters the advice given here and elsewhere. What gives? Did I ruin my La Lune, Black Shadow, and Translucent Ark by lapping them with sandpaper?

Personally I could never use one that wasn’t lapped. IMHO Arks are not ready for use straight out of the box and they aren’t consistent until flattened and lapped to a desired grit.

This is the same stone. Dan’s Blue-Black
1425349B-FF79-457B-BA72-FED45A8F1203.jpeg

5802F7A8-49E1-49DC-BF83-F71DEA1E51B2.jpeg
 
Personally I could never use one that wasn’t lapped. IMHO Arks are not ready for use straight out of the box and they aren’t consistent until flattened and lapped to a desired grit.

This is the same stone. Dan’s Blue-Black
View attachment 1476499
View attachment 1476498
The bench and pocket stone I've goth from Dan came perfectly flat, the primitive cut translucent... not so much. I expected a rough cut stone and only moderate flatness on one side but $50 for a 4.5"x5" translucent Ark of proven quality was hard to pass up. That size is great for all manner of tools and blades. Dans finishes to 600# and I think that right about the sweet spot for me. When it gets burnished I refresh it with a worn out 1k# diamond plate, just lightly buff it and it's cutting quickly again. I've been tempted to ask Kim if they have any of that super soft, really really friable nü- washita in their quarry, the kind that's so soft it wears way too fast to be a long term whetstones. The kind sitting around and mostly being used for tripoli powder. Id like to get some of it to use as a slurry stone on washitas and arks when honing knives. I've used some of the newer multicolored washitas and they're good, just a little too hard/ not friable enough. I've got a coarser charnwood (around 8k) that's pretty friable for a dense stone and with a little slurry raise by putting my harder llyn idwal on it, it's lightening fast. This is also why I bought a Cretan stone recently. I've heard they are very friable though dense(probably the calcite) and I think a thick slurry of novaculite(one of, if not the sole ingredient, in tripoli powder) fairly quickly diluted down and then finished on plain stone with oil could make a very quick sharpening set up for tools. My Cretan isn't in yet but once I get it I may do a thread of different novaculite slurries. My mystery green novaculite stone is soft and when I use that same llyn to raise a slight slurry it's really fast, the slurry seems to break down, and it leaves a toothy but very fine edge.
 
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The bench and pocket stone I've goth from Dan came perfectly flat, the primitive cut translucent... not so much. I expected a rough cut stone and only moderate flatness on one side but $50 for a 4.5"x5" translucent Ark of proven quality was hard to pass up. That size is great for all manner of tools and blades. Dans finishes to 600# and I think that right about the sweet spot for me. When it gets burnished I refresh it with a worn out 1k# diamond plate, just lightly buff it and it's cutting quickly again. I've been tempted to ask Kim if they have any of that super soft, really really friable nü- washita in their quarry, the kind that's so soft it wears way too fast to be a long term whetstones. The kind sitting around and mostly being used for tripoli powder. Id like to get some of it to use as a slurry stone on washitas and arks when honing knives. I've used some of the newer multicolored washitas and they're good, just a little too hard/ not friable enough. I've got a coarser charnwood (around 8k) that's pretty friable for a dense stone and with a little slurry raise by putting my harder llyn idwal on it, it's lightening fast. This is also why I bought a Cretan stone recently. I've heard they are very friable though dense(probably the calcite) and I think a thick slurry of novaculite(one of, if not the sole ingredient, in tripoli powder) fairly quickly diluted down and then finished on plain stone with oil could make a very quick sharpening set up for tools. My Cretan isn't in yet but once I get it I may do a thread of different novaculite slurries. My mystery green novaculite stone is soft and when I use that same llyn to raise a slight slurry it's really fast, the slurry seems to break down, and it leaves a toothy but very fine edge.
Daggone, you have a lot of toys! I’m jelly!
This is one of the strong attractions to Arks, you can tailor them to your liking, and with two usable sides, you can give yourself two options. I’ve tried a number of different things and I always come back to as flat and smooth as possible on my finishing Arks. Personally I think it great that not everyone does it the exact same way.

That said, I have never considered Ark powder as a slurry. I would think that the particle size would be too large. Glad to have someone exploring and pushing the knowledge base.

Interestingly I have a Dan’s black pocket stone (amongst other Dan’s offerings - however no washitas as of right now) that all it does is eat edges. I think I need to abrade more of the surface and get further down to get a better surface. In current form, any edge leading pass gets eaten. It’s interesting.

On the other end I also got this Dan’s hard. Here’s two pics. Out of the box and after lapping:
C3C38D2D-2493-4439-AFBE-45A63EC08305.jpeg
1D71C8E9-74D0-4E57-996C-84E1920C77A1.jpeg


I asked Dan’s for a set up stone for the finisher and this is what I got. It is able to reflect light but it has a bit of texture on the surface similar to a 3K synthetic. Wonderfully wide range on this stone and I wish I would have got one a long time ago.

I bet those foreign novaculites are a lot of fun too.
 
Daggone, you have a lot of toys! I’m jelly!
This is one of the strong attractions to Arks, you can tailor them to your liking, and with two usable sides, you can give yourself two options. I’ve tried a number of different things and I always come back to as flat and smooth as possible on my finishing Arks. Personally I think it great that not everyone does it the exact same way.

That said, I have never considered Ark powder as a slurry. I would think that the particle size would be too large. Glad to have someone exploring and pushing the knowledge base.

Interestingly I have a Dan’s black pocket stone (amongst other Dan’s offerings - however no washitas as of right now) that all it does is eat edges. I think I need to abrade more of the surface and get further down to get a better surface. In current form, any edge leading pass gets eaten. It’s interesting.

On the other end I also got this Dan’s hard. Here’s two pics. Out of the box and after lapping:
View attachment 1476600View attachment 1476601

I asked Dan’s for a set up stone for the finisher and this is what I got. It is able to reflect light but it has a bit of texture on the surface similar to a 3K synthetic. Wonderfully wide range on this stone and I wish I would have got one a long time ago.

I bet those foreign novaculites are a lot of fun too.
I think with one of the ones that are extremely friable the slurry would break down pretty quick rubbing against that hard stone but would still be very fast.
 
"Aren't meant to be lapped"
Based on what, exactly? What does that even mean? It's a rock. who's to say what it was 'meant' to be?

People have been lapping Arks flat forever. Oscar over at Preyda was investing in some machinery for the sole purpose of lapping Arks.
Slates ? Same...
Surface condition....if I am sharpening tools, I won't want to get most slates over 2-300x. I leave Eschers at 220x usually actually, and that is for razors. Finely lapped slates have not proven to be better and in some cases have proven to be less effective and not very consistent, etc. That's for finishing razors, there no point in lapping slate so very fine if the task is mid-range work on a chisel or work blade. After tons of testing tons of slates, that's, generally, what I found to be my norm. Other people might have tried different things different ways and have then decided that other ways suit them better.
I lap often to remove glazing; to keep the surface as continuous as possible.

Arks, depends on which arks and what tools. Washita and Trans Arks would require different surfaces for different tasks. I never lap any Ark over 600x but I won't be using that 600x surface for anything but razors.
Yes, surface condition affects cutting speed, depth, etc. Being able to to control those things is part of the game.
Some slates require frequent lapping to maintain flatness, others not so much. Tool sharpening doesn't alway require super flat surfaces, depends on the tool actually, but I don't go nuts flattening stones for cutlery unless I am beating up on them. But still, I lap them flat regularly enough and for good reasons.
 
"Aren't meant to be lapped"
Based on what, exactly? What does that even mean? It's a rock. who's to say what it was 'meant' to be?
LOL. Exactly. I wondered the same thing myself when I got his email. He didn't explain any further.
 
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