A sharpening thread of my very own (Japanese Natural Stones).

[Kees Heiden]

Brian, I have a question. On rereading your blog post I thought: He starts on a real fine stone! 3000-5000 grit is almost a finish stone in my book. Don't you need something coarser to start with?

[Brian Holcombe]

Barbecue, ha? In that case, you're coming to my place (I have a restaurant in Essex county and we grill on 1000 degree+ charcoal - our salmon is sushi grade too) but you have to be good with Greek food (real Greek food, no gyro!).

EDIT: Loving those chopsticks

Do kalofagas and souvlaki count? I love both!

Hehe, have yanagi-ba, will travel

I can't believe you people are off topic on Que....whoever went off subject might need to be flayed, ohh wait.... I am more of a low, looong and slow guy, brisket, chicken, pork butt, ribs, hardwood charcoal and my own apple wood. It takes me at least two days to make serious Que. I hope you people know how to make slaw, because eating Que without slaw is just uncivilized. Steaks, now that is where you need a little more heat....

The Spyderco stones seem to work differently to me. They work more like an eraser. The steel seems to sort of smear across the surface of the stones. Not at all like my Sigma Power Select 2's which seem to work more like the jnats.

Now I know where I'm stopping if travel to GA! Japanese tools plus Barbecue!

I forgot about chicken, I have chicken drumsticks to a science. We have some good friends who cook Chinese specialties for us all winter as a bribe for summer BBQ.

Brian, I have a question. On rereading your blog post I thought: He starts on a real fine stone! 3000-5000 grit is almost a finish stone in my book. Don't you need something coarser to start with?

I can start with something more coarse, but that would be a synthetic, as with most things it depends.

For fine paring chisels I almost never let them get noticeably dull, so they're worked mainly on the Shinden and Nakayama stones, then once in a while I'll work them from 1k synthetic all the way on through the regimen. For chisels that I use for chopping or plane irons they are most often seeing Tsushima through Shinden and for detail or finish work I'll work them on the Nakayama stone as well.

I use this set for western irons as well, the try plane is easily worked on the Tsushima and Yaginoshima and the Jack plane usually Ikarashi and Tsushima.

Gouges would be Ikarashi - Tsushima - Hakka.

[Kees Heiden]

Thanks for the answer Brian.

Usually I start with a fine India, so you can probably understand my bewilderment?

[Mike Holbrook]

Felt guilty for going off topic again, so I removed and then added back my Que comments.... Any time Brian. I never know when the daughter and her boy friend or one of our "semi" adopted young adults might drop by for dinner so I usually cook extra.

Now I am wondering about a jnat finisher to follow Spydercos...no, no I am too close to the razor sharp edge!

[Brian Holcombe]

Kees, I understand exactly. It's a fluid process always determined by how far I've worn something. I have a 325 grit synthetic if I need it, but not usually a part of regular maintenance. If for some reason I'm wearing a chisel or iron until it is very dull I will start there. For A2 I usually start there as well, since I just want to work it quickly.

I like my chisels extremely sharp and so I sharpen them far more often than probably most would consider necessary.

Mike, no worries!

Haha, there is a reason why So has so many warnings on his website!

[Kees Heiden]

Just bought a Belgian coticule, so I am not completely immune for stone fetishment either

[Stewie Simpson]

Do kalofagas and souvlaki count? I love both!

Hehe, have yanagi-ba, will travel



Now I know where I'm stopping if travel to GA! Japanese tools plus Barbecue!

I forgot about chicken, I have chicken drumsticks to a science. We have some good friends who cook Chinese specialties for us all winter as a bribe for summer BBQ.



I can start with something more coarse, but that would be a synthetic, as with most things it depends.

For fine paring chisels I almost never let them get noticeably dull, so they're worked mainly on the Shinden and Nakayama stones, then once in a while I'll work them from 1k synthetic all the way on through the regimen. For chisels that I use for chopping or plane irons they are most often seeing Tsushima through Shinden and for detail or finish work I'll work them on the Nakayama stone as well.

I use this set for western irons as well, the try plane is easily worked on the Tsushima and Yaginoshima and the Jack plane usually Ikarashi and Tsushima.

Gouges would be Ikarashi - Tsushima - Hakka.

Brian; correct me if I am wrong; but all you have been able to do is identify the mine location that each of your Japanese Natural Stones were quarried from. That is of limited value. http://www.japanesenaturalstones.com...atural-stones/

Natural stones Quarries
Nakayama 中山
Mizukihara 水木原
Oohira 大平
Okudo 奥殿
Shoubudani 菖蒲谷
Oozuku 大突
Shinden 新田
Nartuaki - 鳴滝 (also has 2 meaning: mine name and east mines)
Kouzaki 神前
Hideriyama 日照山
Atagoyama 愛宕山
Yaginoshima 八木ノ嶋
Hakka 八箇
Sororo Ozaki 尾崎
Okunomon 奥ノ門
Otoyama 音羽山

Takashima 高島
Wakasa 若狭 : near Fukui mountain name is Miyama

Shiroto: connected to Oozuku Maruoyama
Yaginoshima 八木の嶋 Kizuyama 木津山

Saeki 佐伯
Kinugasayama 衣笠山


A cutting ability of a stone will also be noted.

1. Mine (Nakayama, Ohira, Hakka, etc.)
2. Strata (Tenjyou, Namito, Tomae, etc.)
3. Appearance (Kiita, Karasu, Asagi, etc.)
4. Stone Level (Lv1 - Lv 5, Lv 5 - hardest) So example will be: Ohira Tomae Lv 2, Nakayama Asagi Lv
5. Shinden Suita Renge Lv 3.5 Stratas From soft on top and very hard on the button.

[Stanley Covington]

Its been a long busy day, and at last I have a few minutes.

In response to Kee's question (I am always uncertain of whether or not Kee's questions and comments are sincere, or just malicious yanking of the proverbial chain), I think you can figure out how to avoid burnishing a blade on an Arkansas stone on your own. (Hint: Don't use an Arkansas stone).

I will respond to the question about reasons to avoid burnishing a blade. Burnishing results from plastic deformation of the surface metal as you described, essentially pushing the metal around rather than cutting it off in scratches and furrows. It is caused by pressure and heat, where the pressure creates the heat. The heat in turn can cause the very thin wedge of metal at the cutting edge to overheat in places, softening it. This softer metal of course looses its carbide crystals relatively quickly in use, dulling more easily than metal that was not subjected to this heat.

Now some of you are saying: "But steel doesn't lose its temper until it turns blue.... or reaches 1600 degrees. That could never happen on a sharpening stone," or some other such reasonable sounding intuitive nonsense. I am talking about the microscopic level and extremely localized softening. Softening like this doesn't make any difference when looking at a slab of steel, such as an entire plane blade with a relatively thick layer of steel surrounding the carbides and their supporting, softer steel matrix, which acts as a heat sink. But it does make a difference at the ragged cutting edge of that same blade where heat is not so easily dissipated.

To avoid this localized loss of temper, one must avoid (i) high pressures and; (ii) high temperatures. This is most easily accomplished by keeping the stone wet and developing a slurry to serve as both lubricant and coolant. The second technique is to decrease pressure on the last few stroke on the finishing stone.

Stan

[Brian Holcombe]

Stewie, it is a fair point and thank you for reading the blog as well. Even with all of that information above the ability of the stone will continue to be somewhat vague because there is a range of characteristics presented by each type of stone i.e. You can have Okudo suita which cuts like a medium-finisher (somewhat harsh) all the way out to extremely fine.

What I'm not creating is a how-to guide because it would be practically useless to anyone who hasn't used my stones. That is why almost all of the dealers will explain hardness and cutting ability of the stones they are selling. That also why most of them present a sequence in somewhat vague terms, because it is always case specific.

Furthermore there are practical understandings of many of the references, often Nakayama asagi, which only points out mine and color characteristic is generally referring to deep strata stones meant for fine finishing.

These are some of my reasons behind titling the post 'A user's perspective', I wanted to avoid implying this would be a guide.

[Stewie Simpson]

Thanks Brian; appreciate the follow up.

regards Stewie;

[Kees Heiden]

Its been a long busy day, and at last I have a few minutes.

In response to Kee's question (I am always uncertain of whether or not Kee's questions and comments are sincere, or just malicious yanking of the proverbial chain)

I love it to keep you on your toes But I don't know how much credit I have left after the elbows thread.

, I think you can figure out how to avoid burnishing a blade on an Arkansas stone on your own. (Hint: Don't use an Arkansas stone).

I will respond to the question about reasons to avoid burnishing a blade. Burnishing results from plastic deformation of the surface metal as you described, essentially pushing the metal around rather than cutting it off in scratches and furrows. It is cause by pressure and heat, where the pressure creates the heat. The heat in turn can cause the very thin wedge of metal at the cutting edge to overheat in places, softening it. This softer metal of course looses its carbide crystals relatively quickly in use, dulling more easily than metal that was not subjected to this heat.

Now some of you are saying: "But steel doesn't lose its temper until it turns blue.... or reaches 1600 degrees. That could never happen on a sharpening stone," or some other such reasonable sounding intuitive nonsense. I am talking about the microscopic level and extremely localized softening. Softening like this doesn't make any difference when looking at a slab of steel, such as an entire plane blade with a relatively thick layer of steel surrounding the carbides and their supporting, softer steel matrix, which acts as a heat sink. But it does make a difference at the ragged cutting edge of that same blade where heat is not so easily dissipated.

To avoid this localized loss of temper, one must avoid (i) high pressures and; (ii) high temperatures. This is most easily accomplished by keeping the stone wet and developing a slurry to serve as both lubricant and coolant. The second technique is to decrease pressure on the last few stroke on the finishing stone.

Stan

Not using my coveted Arkansas stone .

All the above may be true, but it doesn't quite explain that in real use the Arkansas stone, followed by some stropping delivers a very durable edge. For example, I am now almost through planing the faces of all rails and stretchers and legs of the cabinet I started to build. I haven't resharpened the tryplane blade yet. Another example, I made a couple of wooden planes last winter and chopped the entire mortice and paired all the surfaces except the abutments on a single sharpening of my big old Dutch 3/4" timber framing chisel. After that I made a carefull observation of the edge and it hadn't chipped at all and was still sharp enough to do a half decent endgrain paring on pine. And I was not too carefull, really waled on that sucker and pried quite a bit too.

In theory you may be right, in practice it is hard to see evidence. Maybe it is the difference bwteen the western tools with the less critical sub 60 Hrc hardening and the Japanese tools tempered up to 64.

Burnishing is not always regarded to be a bad thing in mechanical stuff. It can certainly be fatal for gliding components, but before it is fatal it smoothes a surface and workhardens the surface. That kind of contradicts the overheating theory.

[Patrick Chase]

Its been a long busy day, and at last I have a few minutes.

In response to Kee's question (I am always uncertain of whether or not Kee's questions and comments are sincere, or just malicious yanking of the proverbial chain), I think you can figure out how to avoid burnishing a blade on an Arkansas stone on your own. (Hint: Don't use an Arkansas stone).

I will respond to the question about reasons to avoid burnishing a blade. Burnishing results from plastic deformation of the surface metal as you described, essentially pushing the metal around rather than cutting it off in scratches and furrows. It is cause by pressure and heat, where the pressure creates the heat. The heat in turn can cause the very thin wedge of metal at the cutting edge to overheat in places, softening it. This softer metal of course looses its carbide crystals relatively quickly in use, dulling more easily than metal that was not subjected to this heat.

Deformation on this scale typically hardens metals if anything (strain hardening), though that's not really applicable to super-hard tool steels.

The phenomenon you describe is theoretically possible under very rapid deformation, but there's a minor conservation-of-energy problem for hand sharpening. I don't think that a human could add energy fast enough by moving their arms back and forth to achieve those sorts of temperatures even locally, keeping in mind that the whole process is liquid (water, oil) cooled and that metals are very conductive.

Can you point me to any direct evidence of this happening during hand sharpening? Again, I know it can happen with very large power inputs, but that's not what we're talking about here.

[Kees Heiden]

I am a bit sceptical about the heat problem too Patrick.

The advantageous effects of burnishing surfaces is real. Look up low plasticity burnishing for example. But:
- If it is beneficial for a surface, is it also benificial for an edge?
- Does it really happen when you use a well worn in Arkansas stone? I am pretty sure I have seen some SEM pictures in a book about the difference between sharp edged grit and rounded grit and you could see the plastic deformation very clearly. But of course I can't find them anymore.

And another question, those very special, very hard and fine natural Japanese stones like they use for rasors, do they have some burnishing effect too?

[Warren Mickley]

Not all of us are as inexperienced with Arkansas stones as Stan. His arm chair theories are incompatible with real world experience.

[Stanley Covington]

All the above may be true, but it doesn't quite explain that in real use the Arkansas stone, followed by some stropping delivers a very durable edge. For example, I am now almost through planing the faces of all rails and stretchers and legs of the cabinet I started to build. I haven't resharpened the tryplane blade yet. Another example, I made a couple of wooden planes last winter and chopped the entire mortice and paired all the surfaces except the abutments on a single sharpening of my big old Dutch 3/4" timber framing chisel. After that I made a carefull observation of the edge and it hadn't chipped at all and was still sharp enough to do a half decent endgrain paring on pine. And I was not too carefull, really waled on that sucker and pried quite a bit too.

In theory you may be right, in practice it is hard to see evidence. Maybe it is the difference bwteen the western tools with the less critical sub 60 Hrc hardening and the Japanese tools tempered up to 64.

Burnishing is not always regarded to be a bad thing in mechanical stuff. It can certainly be fatal for gliding components, but before it is fatal it smoothes a surface and workhardens the surface. That kind of contradicts the overheating theory.

Sorry to be late in responding, Kees. Traveling again.

You mentioned stropping. I believe in it, and am a big fan of stropping my Japanese planes and chisels, as I mentioned in a post to a different thread where, once again, Warren dismissed my experience as totally insignificant. It has nothing to do with burnishing, but I believe it cleans up the ragged edge left by the stones a bit, and helps it stay sharp a bit longer. I do it on the heel of my palm, with a bit of mud from my finishing stone on my skin. I don't think it heats up the edge like a leather or linen strop used too vigorously can. Stropping works.

I also agree with you about the positive benefits of burnishing in some applications. I just don't like the potential for burnishing to overheat and soften the edge.

Work hardening and burnishing are not the same thing, and do not necessarily occur together. Work hardening does not necessarily make for a improved cutting edge, since it creates an increased yield strength (harder) by dislocating the crystalline lattices in the material in plastic deformation, NOT by making the lattices stiffer through the production of small, uniform, very hard carbides.

Stan