# Pro Needing Advice



## BloodrootLS (Oct 30, 2015)

Hey guys, 

David and I are in need of some advice. We sharpen a lot of knives, all carbons, and stone durability and ability to withstand permasoak are important considerations, since we use them at any time during the day, multiple times, and need them ready in our sharpening station at all times. 

The main problems we're having is with repairs and initial edge setting. We've been using coarse DMT's for the last few years since they stay flat, but we wear them out about once every 6 weeks and always have several in rotation since after a month or so they're nearly worthless and they're not ideal when they're absolutely fresh. We've also been unhappy with the unevenness of the diamond application- some stones we've gotten have had clumps on the surface and it takes a week or so of use to wear them in and they just don't cut smoothly when they are in that condition. Only 2 out of the last 8 have had this problem. The other issue is that they are expensive at the rate they wear out for us and end up generating a lot of waste.

What do you guys suggest for this kind of work? I don't mind flattening a coarse stone relatively frequently, but the cheap Nortons etc. that I've used in the past weren't fun to use either and wore out super quickly. 

We are happy with our Suehiro #1200 stone. Great feel, pretty hard and durable, but still breaks down enough for a good slurry. The Norton 1000 we have is nice and fast cutting, but soft and dishes quickly. We typically don't use it and prefer the Suehiro. 

We are ambivalent/mildly unhappy with our King #6000. Loads quickly and have to use the nagura often and also seems to either hold pieces of grit on the surface or else have an uneven grit size. Not as smooth cutting as I like. We recently got a Shapton #5000 and neither of us like it at all. Soft and doesn't seem to cut smoothly either. Similar faults to the King, but softer and less friendly. 

We have an unknown #4000 that's just amazing. I wish beyond all things that I knew what it was but we inherited it from a woodworker and it has no markings. It's quite hard and cuts aggressively but smoothly.

We also use an unknown #8000 that's ok, but very soft. 

Do you all have any suggestions for what would improve our collection?

We greatly appreciate your advice. 

Best, 

~Luke


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## JDA_NC (Oct 30, 2015)

Jon @ JKI has some very cool diamond stones that he sells. I know he has a few coarse options but he's also done a few group buys with a 1k/6k set. I love them myself and across the board folks really seem to like them.

He also has more experience with high volume use than most of us combined. If you were to shoot him an e-mail or give him a call, I'm sure he would be happy to talk shop.

Best of luck. (Love y'all's knives!!)


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## jklip13 (Oct 31, 2015)

I strongly recommend taking a look at the Shapton M24 line, the 120 grit especially. It is the only thing I've ever found that is comparable in speed to an Atoma Plate. I've never soaked this stone though so I don't know how it will react. Best of luck


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## Eric (Oct 31, 2015)

Why not set the bevels on your grinder rather than with the stones?


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## panda (Oct 31, 2015)

suehiro cerax 320, it dishes but cuts amazingly fast and is the best feedback of any coarse stone and is super cheap, although i'm not sure if it's permasoakable. if not, maybe king 300 which is splash n go? another good one is chosera 3000 cuts well stays flat doesn't load (does not require soaking its straight up splash & go) and is only $104 on amazon but you won't have to replace it for a long arse time (can attest to this as mine gets constant use in pro kitchen)


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## buttermilk (Oct 31, 2015)

I've had too many whiskey cocktails and fernet but I think I understand.

Answer #1 - Atoma 140 and belt grinder. Ditch DMT and get an Atoma 140. I had used DMT for years until recently, and immediately realized the mistake. Atoma for diamond flattening. You guys are using grinders, right? I'd guess you are but I haven't been paying close enough attention to remember. Grinders flatten blade, grinders also flatten stones. It's great. It's dusty and it's great. 

Answer #2 - Cerax 320s are great. I love them but I, for pro use, hate them. You guys are doing far more volume than me, and I can't imagine dealing with even the most ideal coarse stone. That said, the Cerax 320 is everything you want from a coarse stone, except it dishes quickly. 

Answer #3 - Rika 5k, or JNS 6k, but really just the Rika 5k. Readily available, cheap, extremely slow wearing, fasting cutting, nice finishing, perfect kitchen edge. Ideal.

I'll add more when I'm sober. I love your work, by the way!


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## fimbulvetr (Oct 31, 2015)

Fwiw, I've permasoaked my Cerax 320 for about 5 months now. No issues so far.

It may be though that, as it gets thinner, it gets more brittle.


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## no_one_just_Roy (Oct 31, 2015)

Never tried myself and I wonder if my guesswork is correct... but I think Gesshin 220 might be worth trying.

Well, you can't permasoak Shaptons, so that's a no-go idea. In water they get softer and eventually disintegrate.
(You might think you don't have to state the obvious but that doesn't do good for other readers... )


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## berko (Oct 31, 2015)

> Shapton #5000 and neither of us like it at all. Soft and[...]



you must have been using dmts for too long, thinking of the shapton 5k as beeing soft  any chance in getting some pictures of your current 4k and its measurements? maybe anybody can help then.


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## Mucho Bocho (Oct 31, 2015)

Luke, you may have already seen this but JKI offers a 400 grit diamond stone. I haven't heard of anyone on the forum that's bought one but if Jon sells it, I'm sure it's the real deal. You could then add his 1000 & 6000 and have a complete splash and go diamond line up. 

http://www.japaneseknifeimports.com/new-items-list/diamond-300a-stone-and-flattener.html


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## buttermilk (Oct 31, 2015)

Yikes, I probably shouldn't have been posting last night. My apologies. 

It seems like everyone has spoken to what you're actually looking for already. For bevel setting/repairs the JNS 300 is slow dishing, fast cutting, splash and go, and not very muddy. As Mucho Bocho said, Jon's 400 diamond might be a great solution as well. I'm sure Jon would be happy to speak to this. The Cerax 320 is a great cutter and does give great feedback but it definitely dishes quickly. They can be permasoaked without issue. Even just trying the Atoma 400 instead of the DMT coarse could be worthwhile. I've found the Atomas to wear a bit slower. The Rika 5k is a great stone in feedback, wear, cutting, and finished edge, but it doesn't polish.


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## psfred (Oct 31, 2015)

I will share my minimal experiences:

Diamond plates must be used with VERY light pressure -- the diamond dust is held to the backing with nickel plating, and heavy pressure will roll the diamond out quite rapidly. Used with feather light pressure they will cut well for a very long time, with significant pressure you can strip even good ones in minutes. Been there, done that. You should also consider that coarse diamond on steel plate has no give at all, and the pressure at the apex of an edge can easily exceed the fracture strength of the steel, causing micro-cracks. The harder (and hence more brittle) the steel, the worse this effect is. Not usually a problem at finer grits, but coarse ones can be hard on the edge.

A King Deluxe 300 grit stone will not dish for a very long time if used with a light hand -- higher pressure will make it cut a bit faster, but it will also roll grit off that light pressure does not. Mine stays flat very well, have only needed to flatten it a couple times while flattening the back and restoring the bevel of half a dozen abused plane blades. Splash and go. Not available in the US I don't think, I got my from Stu at ToolsfromJapan.

In general, high pressure while sharpening is undesirable with waterstones of any kind. They don't cut faster with more pressure, unlike Arkansas stones, but they DO dish much faster as you roll the grit off. Mud has it's place in sharpening, but not for grinding -- this is why I quit using King stones in the 800 to 1200 grit range, too easy to dish them without quick cutting, and if you use light enough pressure not to dish them excessively, they take forever to cut.

The King 6000 is a perfectly adequate stone for a typical person who sharpens his own knives -- I've had one for something like 20 years and it works fine. Wears too fast for professional sharpening use, I think. Suehiro Rika is probably a better choice as it appears to cut faster and wear less, at least so far. King is a splash and go, Rika is a soaker. No experience with other stones to speak of as I've not actually used my Arashiyama 6K yet, it's still in the box. Probably better results than the King, but I can't advise on wear rate.

For repairs, removing nicks, etc I would use a belt sander with boron nitride belts, running at low speed. Used with care a belt sander will remove far more metal in a given amount of time than a stone, and you won't need to do anything but the coarse work with it. If you are really serious, a Burr King or equivalent knife grinding belt sander will save you mountains of money on repairs.

I am trying to learn to use the whole surface of the stone and "work down" high spots to avoid excessive flattening, something you may want to pursue if you have not done so yet. It's tempting to just grab that flattener all the time, but working the stone as flat as possible will reduce the wear rate quite a bit and should also give you better results on the knife.

Peter


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## chefcomesback (Oct 31, 2015)

psfred said:


> I will share my minimal experiences:
> 
> Diamond plates must be used with VERY light pressure -- the diamond dust is held to the backing with nickel plating, and heavy pressure will roll the diamond out quite rapidly. Used with feather light pressure they will cut well for a very long time, with significant pressure you can strip even good ones in minutes. Been there, done that. You should also consider that coarse diamond on steel plate has no give at all, and the pressure at the apex of an edge can easily exceed the fracture strength of the steel, causing micro-cracks. The harder (and hence more brittle) the steel, the worse this effect is. Not usually a problem at finer grits, but coarse ones can be hard on the edge.
> 
> ...



I am not sure if you read the op, these guys make knives for living , yes they do have grinders


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## SousVideLoca (Oct 31, 2015)

chefcomesback said:


> I am not sure if you read the op, these guys make knives for living , yes they do have grinders



Right? I'm shocked they _don't_ set their bevels and do the finish sharpening on grinders. That's like, a whole new level of crazy. _IT'S CRAZY._


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## chefcomesback (Oct 31, 2015)

SousVideLoca said:


> Right? I'm shocked they _don't_ set their bevels and do the finish sharpening on grinders. That's like, a whole new level of crazy. _IT'S CRAZY._



That wasn't my point but yes I do have grinders too and once the edge gets so thin i rely on coarse stones heavily . Once the edge is less then .5mm it overheats very easy , I rather go slow and take it to the stones after that stage . I guess that's the reason they are looking for something like diamond stones ( me too)


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## gic (Oct 31, 2015)

The 3m diamond plates may be an alternative to the atomas. I know Jon has use them so he may weigh in on the pros and cons of them versus the atomas in a pro setting


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## efaden (Oct 31, 2015)

gic said:


> The 3m diamond plates may be an alternative to the atomas. I know Jon has use them so he may weigh in on the pros and cons of them versus the atomas in a pro setting




3m diamond plates?


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## Pensacola Tiger (Oct 31, 2015)

efaden said:


> 3m diamond plates?









http://www.amazon.com/gp/product/B00AW16MD6/?tag=skimlinks_replacement-20


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## JBroida (Oct 31, 2015)

i like the 3m plates, but i blast through one in about 2-3 weeks when using at a normal pace


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## efaden (Nov 1, 2015)

JBroida said:


> i like the 3m plates, but i blast through one in about 2-3 weeks when using at a normal pace



2 to 3 weeks.... $300... holy cow. Why are they better than Atoma?


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## SousVideLoca (Nov 1, 2015)

efaden said:


> 2 to 3 weeks.... $300... holy cow.


They're $76 each, not $300.


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## efaden (Nov 1, 2015)

Ah... didn't noticed it wass for 3... phew... How do they compare to the Atoma?


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## gic (Nov 1, 2015)

You can get them from many vendors not just amazon and Amazon doesn't always have the best prices, they are sold widely in industrial supply places where 3M is so important. Here's another place I found by a quick google search

https://www.pack-n-tape.com/cart/3M...tstone-8-in-x-3-in-M74-Micron-3-per-case.html


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## Keith Sinclair (Nov 1, 2015)

You can get a Atoma 140 for around 80.00. I use barkeepers friend and a fingernail brush to clean it. Agree with Peter do not need to press hard when using plates, they will last longer. Initial thinning I am getting more confident on the belt.


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## Benuser (Nov 1, 2015)

Not so sure whether permasoaking is the only solution to your wish to have stones available at any moment. Splash and go's may be an option as well. I have the Naniwa Professional in mind.


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## Castalia (Nov 2, 2015)

I am not a pro, but this came up in a thread a few months ago. http://www.amazon.com/Makita-9820-2-Horizontal-Wheel-Sharpener/dp/B0000223JC

I am thinking it might work well in a busy shop. Of course I have also seen huge waterstone grinding wheels in professional Japanese shops, but those don't seem easy to come by in the states.


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## kohtachi (Nov 2, 2015)

I'm curious what color and size is that 4k? Is it white?


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## BloodrootLS (Nov 2, 2015)

chefcomesback said:


> That wasn't my point but yes I do have grinders too and once the edge gets so thin i rely on coarse stones heavily . Once the edge is less then .5mm it overheats very easy , I rather go slow and take it to the stones after that stage . I guess that's the reason they are looking for something like diamond stones ( me too)



Yes we definitely use grinders to establish the initial edge, but we then clean and even up the edge with the diamond plate. Many styles of knives that we build are ground so that the edge is thin enough that the sharpening bevel is nearly a microbevel and in these cases we take it down by hand. I haven't used an Atoma plate yet and that might be a quick and easy thing to try. I'll also get one or two of the other coarse stones you guys have been mentioning and give them a try. 

The Rika 5000 sounds like a great stone and something that might be right up our alley. 

Great to know on the Shaptons that they get softer with a permasoak. Perhaps that is the root of our problem with that stone. 

We definitely flatten stones on the grinder. I can't tell you how much time this saves, and with a dust collector it's not as bad as it could be!

I really appreciate all of your feedback, this is very helpful. I look forward to playing with some new stones!

Best, 

~Luke


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## BloodrootLS (Nov 2, 2015)

berko said:


> you must have been using dmts for too long, thinking of the shapton 5k as beeing soft  any chance in getting some pictures of your current 4k and its measurements? maybe anybody can help then.



I'll try to take some pictures of it tomorrow and get some measurements. It's dark red.


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## BloodrootLS (Nov 2, 2015)

Benuser said:


> Not so sure whether permasoaking is the only solution to your wish to have stones available at any moment. Splash and go's may be an option as well. I have the Naniwa Professional in mind.



Yes I suppose I shouldn't be limiting myself. I was just thinking it would be simpler since we have a storage system for the permasoaked stones at our sharpening station and don't have tons of room for laying out stones outside of it. A stone or two wouldn't be bad though since we have the diamond plates out of it. We could also modify our station layout.


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## rick alen (Nov 4, 2015)

psfred said:


> I will share my minimal experiences:
> 
> I am trying to learn to use the whole surface of the stone and "work down" high spots to avoid excessive flattening, something you may want to pursue if you have not done so yet. It's tempting to just grab that flattener all the time, but working the stone as flat as possible will reduce the wear rate quite a bit and should also give you better results on the knife.
> 
> Peter



Ahaha, I overdid that recently and wound up with the reverse effect, convexed instead of concaved.



Rick


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## BloodrootLS (Nov 5, 2015)

rick alen said:


> Ahaha, I overdid that recently and wound up with the reverse effect, convexed instead of concaved.
> 
> 
> 
> Rick



Yeah, I've done something along those lines too. I will often sharpen shorter knives on the "ends" of the stone- turn the stone 90 degrees from its typical direction. It does help keep the stone going. Nothing beats a true flattening though.


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## Benuser (Nov 5, 2015)

To some extent it can be useful when thinning.


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