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

[Brian Holcombe]

:D

With all of the sharpening threads at current I feel a bit left out, so I thought I'd blog away and post it up.

https://brianholcombewoodworker.com/2016/06/26/japanese-natural-stones-a-users-perspective/

Those asking to be pushed over the edge into natural stones territory may find this interesting ;) (Patrick Chase).

[Patrick Chase]

Those asking to be pushed over the edge into natural stones territory may find this interesting ;) (Patrick Chase).

Now when you say "natural stones" you mean a lapping compound consisting of natural diamonds (http://www.psidragon.com/products/ML/POLISHING/DIA%20COMP/NATURAL.aspx), right? I can be TOTALLY down with that...

Very nice writeup!

[Patrick Chase]

Wait, you're slurrying a JNat with a DIAMOND PLATE? People have been burnt at the stake for lesser apostasies.

Of course given that one of the two stones you did that to is a Nagura it isn't clear to me what else you would use?

[Patrick Chase]

OK, I have but one concern, and it relates to the comparison to the synthetic 13K, presumably the Sigma?

I have that stone and know what it can do (based on examination under microscope) and your results look incompletely polished to me, by which I mean that I think those scratches came from the previous grit.

Most people wouldn't use a stone like that to polish the entire bevel of a chisel. They'd instead focus their efforts on the tip, whether by creating a flat microbevel or by creating convexity at the tip by lifting the handle a bit during final polishing. Doing that makes the polishing go faster at the edge and avoids this sort of issue.

It does seem that JNats are uniquely capable of polishing the entire face for what that's worth.

[Brian Holcombe]

I am going to revisit the 13k, Stan mentioned that he also saw that the finish looked a bit suspect. I attributed it to a raking light, in person it looked pretty normal, but it's worth taking another look.

Thanks for your comments, I knew this thread had the potential to be interesting. :D

Also fair point that I would normally not polish the entire bevel with that grit, in fact I had debating including it but thought it may make for an interesting data point.

The slurry created with a Jnat makes for evenly polishing a full bevel to be much more easily achievable.

Tsushima Nagura is not the same as a White Nagura stone, which would be used for slurrying finish stones. Many people are slurrying with a 1200 atoma plate currently.

[Phil Mueller]

Ok, Brian, you started this...so you get to deal with inexperienced questions.
And no, I didn't use search or google first...I read your blog, and I have some basic questions. You're just going to have to deal with the burden of being the credible source for all stones natural.

First, give me the basics of these natural stones. Do you use water, do you always create a slurry with some other medium first, do they need constant flattening like synthetics? Are all these stones actually mined only in Asia/Japan?Would there not be other stones around the world with similar qualities?

Second, that last pair of stones you pictured - Uchigumori - doesn't appear to have a flat face...or am I just not seeing it?

Third, I have a friend who's a geologist working in the mountains of Northern Turkey. Anything you want me to tell him to look for when he's digging up rocks? :D

Thanks for the write up...I enjoy learning...but be warned, this may not be the last of me on this subject.

[ken hatch]

Brian,

Good post. I've done several A&B's of natural vs. synthetic stones. My results tracked very well with yours. Both will sharpen steel very well but there is a different "look" in the finish. BTW, our stones are not too different but I'm still looking for nice Shinden Suita. I've promised myself that will be my last stone.....and yes I've heard that one before, but this time I really mean it....I promise :D.

ken

P.S. I really do make things but when shop time is limited and/or I'm knackered nothing is as relaxing as putting iron to stone and even better to a natural stone.

[Jim Koepke]

Just when I'm starting to spend some money on natural stones from Arkansas you come along with this. :confused:

jtk

[Patrick Chase]

I am going to revisit the 13k, Stan mentioned that he also saw that the finish looked a bit suspect. I attributed it to a raking light, in person it looked pretty normal, but it's worth taking another look.

You bring up an interesting implied point here by mentioning raking light: Directionality.

The scratches from the synthetic stones are strongly oriented in a single direction, while the ones from the slurried JNats appear to be more variable. The same thing happens with sandpaper vs loose grit, even using the same particle size and lapping motion. Basically loose particles (for example in a slurry) can "roll around" semi-randomly and thereby create scratches that aren't precisely parallel to the honing direction, whereas with fixed media (stones w/o slurry, sandpaper) the scratches always follow the honing direction. I can easily see how that could create at least some of the observed difference in your study.

With that said, I've actually looked at results from the 13k under highly directional light and I still think yours look a bit rough :-).

[Patrick Chase]

Sorry to double-double reply again, but...

My two main reservations w.r.t. JNats are the likelihood of serious marital strife (hiding the invoices only gets you so far), and the fact that I like to play with weird steels. I have a whole lot of PM-V11, which is basically PM-D2 but with more Chromium. My only current set of Japanese chisels are HAP40 (basically PM-M4 HSS). My pigstickers are D2 (no PM). It goes on in that vein.

Basically I have a heap of tools that won't play all that well with natural Silicate abrasives. Heck, some of them don't even work all that well on Sigma Select IIs, though diamond paste/film works with everything so that's become my "final line of defense".

[Brian Holcombe]

Ok, Brian, you started this...so you get to deal with inexperienced questions.
And no, I didn't use search or google first...I read your blog, and I have some basic questions. You're just going to have to deal with the burden of being the credible source for all stones natural.

First, give me the basics of these natural stones. Do you use water, do you always create a slurry with some other medium first, do they need constant flattening like synthetics? Are all these stones actually mined only in Asia/Japan?Would there not be other stones around the world with similar qualities?

Second, that last pair of stones you pictured - Uchigumori - doesn't appear to have a flat face...or am I just not seeing it?

Third, I have a friend who's a geologist working in the mountains of Northern Turkey. Anything you want me to tell him to look for when he's digging up rocks? :D

Thanks for the write up...I enjoy learning...but be warned, this may not be the last of me on this subject.

Haha, great post Phil! I flatten them initially much like a synthetic, and I make them very flat to the point where I can't see light under a precision straight edge, and I can check them with my granite plate as well. During use I make a slurry with a 1200 Atoma plate and doing so will keep the finish stones flat (so long as I use it correctly), the Tsushima stone I work over with a 400 atoma after each use.

If you use the full surface of the stone they will remain basically flat and are generally much less maintenance than synthetic stones, sounds ridiculous but that was my main reason for moving in this direction. The mess of synthetic stones is tough for me to deal with without a shop sink, but natural stones are relatively low mess.

The stones all come from Japan and they're unique to specific strata of specific mountains in and around their respective prefectures. I believe they are all near Kyoto, except Tsushima which is an island and the stones are quarried underwater, but there are better sources than myself on where exactly each stone is from.

Uchigurmori are fairly soft stones, while both of those shown actually do have one flat face, I use them for putting a kasumi finish on rounded bevel blades so I build a heavy slurry with them and dont necessarily keep them flat in use.

Sounds like your friend may be in for a wild goose chase in Turkey :D.


Brian,

Good post. I've done several A&B's of natural vs. synthetic stones. My results tracked very well with yours. Both will sharpen steel very well but there is a different "look" in the finish. BTW, our stones are not too different but I'm still looking for nice Shinden Suita. I've promised myself that will be my last stone.....and yes I've heard that one before, but this time I really mean it....I promise :D.

ken

P.S. I really do make things but when shop time is limited and/or I'm knackered nothing is as relaxing as putting iron to stone and even better to a natural stone.

Hah, I do the same, this and setting hoops are both very enjoyable when time is very limited. I wonder if your finish stone is very similar to my Yaginoshima or maybe a bit finer (not the Nakayama, but the other one whose name escapes me). My shinden stone is very odd looking and that was the only way for me to keep it fairly reasonable in terms of price, you can probably still get a brick but wow, they will be out there, it's a great stone to use though, nice action and is often where I stop in normal use (the Nakayama is for times when an extra measure of sharpness is needed).

I built that sharpening bench so that I would run out of space for additional stones and that would be a barrier to new stones...we'll see if it works (not likely).


Just when I'm starting to spend some money on natural stones from Arkansas you come along with this. :confused:

jtk

:D


You bring up an interesting implied point here by mentioning raking light: Directionality.

The scratches from the synthetic stones are strongly oriented in a single direction, while the ones from the slurried JNats appear to be more variable. The same thing happens with sandpaper vs loose grit, even using the same particle size and lapping motion. Basically loose particles (for example in a slurry) can "roll around" semi-randomly and thereby create scratches that aren't precisely parallel to the honing direction, whereas with fixed media (stones w/o slurry, sandpaper) the scratches always follow the honing direction. I can easily see how that could create at least some of the observed difference in your study.

With that said, I've actually looked at results from the 13k under highly directional light and I still think yours look a bit rough :-).

Fair to say is probably showing scratches that shouldn't be there. That is a good explanation of the effect that I suspect works on the surface of a Jnat, once the slurry is created the loose grit, metal particles and water are sort of pushed around on the stone and worked under the bevel, so I would imagine they're doing just as you say.


Sorry to double-double reply again, but...

My two main reservations w.r.t. JNats are the likelihood of serious marital strife (hiding the invoices only gets you so far), and the fact that I like to play with weird steels. I have a whole lot of PM-V11, which is basically PM-D2 but with more Chromium. My only current set of Japanese chisels are HAP40 (basically PM-M4 HSS). My pigstickers are D2 (no PM). It goes on in that vein.

Basically I have a heap of tools that won't play all that well with natural Silicate abrasives. Heck, some of them don't even work all that well on Sigma Select IIs, though diamond paste/film works with everything so that's become my "final line of defense".

For the most part, while they can be a bit pricier than synthetics they are generally not crazy unless you start going after rarity and looks, if you want a big brick Nakayama kiita, then you are going to spend a small fortune, but that is unnecessary on the whole. Most users wouldn't use collector grade stones and collector grade is where you start to spend crazy amounts.

When I got into this I thought that plain high carbon steels were very boring and so I didn't pursue them initially. After some time I realized that the two (plain HC steel and Natural stones) make a great combination, they're enjoyable to work with and they surprised me in terms of durability in medium hardwoods. So, while they dont have much appeal in terms of awesomeness, they do in terms of work enjoyment. What further surprised me were the stones ability to cut blue steel 1, 2 & Togo Kou.

[Mike Holbrook]

I recently watched a David Wearver YouTube video on sharpening mediums. David's point seemed to be for day to day sharpening there is not a particular advantage between: man made Japanese waterstones, natural Japanese Waterstones, US natural sharpening stones, US man made sharpening stones. I believe the implication was that any advantages occurred at the extreme end of polishing\refining which was not a significant reason to incorporate the usually more expensive stones into day to day work.

I know that the Japanese tend to favor natural Japanese stones for sharpening some of their better high carbon steels. I am not sure, even reading Odate's book on Japanese tools, whether or not these preferences are because of preference for traditional methods or because there is some actual improvement in finish or speed of the work? Odate even seems to dance around whether or not natural/traditional stones work better/faster than man made......stones. Maybe I am missing something?

It seems to me that the very fine stones typically cost much more money but arguably produce slight improvements that may be destroyed the first time the sharpened tool strikes wood. It seems to me to be more logical to spend money on coarser/less expensive abrasives, particularly those that remove more metal faster, in order to maximize ones return on ones investment. For some reason, which I do not seem to understand, many people spend the majority of their funds in what seems to me to be an ill advised attempt to get the ultimate fine stones. The logic seems to be that a very fine stone will produce a very sharp blade which seems to me to be exactly ass backwards. The skill of the person doing the sharpening and the techniques they use to establish bevels/microbevels seems to produce superior results when it comes to getting things sharp. A person with a lesser skill set, IMHO, will just get slowed down/frustrated by a large assortment of slower working abrasives. Although I understand many of the posters here know exactly how to milk theses stones for their full worth...

I certainly do not mean to imply that Brian is pushing people to expensive very fine stones. I know he is discussing a wide range of stones and a successful methodology. I am just concerned that some may walk away from this discussion with the belief that there are magic stones that will all of a sudden make their tools "sharp as razors".

[Patrick Chase]

I recently watched a David Wearver YouTube video on sharpening mediums. David's point seemed to be for day to day sharpening there is not a particular advantage between: man made Japanese waterstones, natural Japanese Waterstones, US natural sharpening stones, US man made sharpening stones. I believe the implication was that any advantages occurred at the extreme end of polishing\refining which was not a significant reason to incorporate the usually more expensive stones into day to day work.

As with almost all woodworking advice, you have to carefully consider the context to determine if it will be valid for you. In this case the big variable is what steel[s] the person providing the advice sharpens. IIRC David mostly uses HCS these days, and what you say is reasonably valid for his usage. I have a bunch of tools made of more "exotic" steels, and no Silicon-Oxide-based medium (natural waterstone, arkansas, etc) is effective with those. The abrasive particles themselves are simply too weak/soft for such metals.

[Brian Holcombe]

My goal when trekking down this path was a durable edge on HC steel. Ultimate sharpness can be fleeting but an edge that stays intact makes for a better cut after that initial extreme sharpness is gone. A durable edge is also easier to bring back to life as it only requires quick work.

I think what I'll do is post up a video of sharpening some fairly hard steel very quickly with these stones, working the full bevel.

[Patrick Chase]

My goal when trekking down this path was a durable edge on HC steel. Ultimate sharpness can be fleeting but an edge that stays intact makes for a better cut after that initial extreme sharpness is gone. A durable edge is also easier to bring back to life as it only requires quick work.

I think what I'll do is post up a video of sharpening some fairly hard steel very quickly with these stones, working the full bevel.

Brian brings up a very good implicit point here: Average hardness is not the problem. SiOx can sharpen low-alloy HC steels up to the mid Rc60s without any problem.

The real issue is uniformity of hardness. Medium-alloy steels like A2 and higher-alloy ones like D2 form carbides as part of their grain structure, and those carbides are well up into the Rc70s. A soft abrasive like SiOx can't abrade the carbides directly, but instead slowly abrades the metal around them until they fall out, leading to both slow honing and edges that are dull/chipped from the start.

The combination of carbides and softer metal in a high-alloy steel can (very) conceptually be thought of as a microscopically laminated blade - the ultra-hard carbides provide abrasion resistance, while the softer metal around them provides toughness.

[Brian Holcombe]

Exactly, I've worked A2 on Jnats and the visual effect seems like what you are describing, abrasion around very hard carbides.

[Phil Mueller]

Thank you Brian.

[Mike Holbrook]

My goal when trekking down this path was a durable edge on HC steel. Ultimate sharpness can be fleeting but an edge that stays intact makes for a better cut after that initial extreme sharpness is gone. A durable edge is also easier to bring back to life as it only requires quick work.

I think what I'll do is post up a video of sharpening some fairly hard steel very quickly with these stones, working the full bevel.

I am trying to understand this information. I have read a good deal of discussion on knife forums about how deceptive Rockwell "hardness" testing can be. The argument being that "hard" at some point can become brittle, resulting in chipping, whereas "tougher", but softer, may hold it's shape longer. Tougher may bend but not break.

Brian, I am wondering if you feel the Jnats (Japanese natural stones?) are capable of producing a superior edge in some regards? I think you were directing your comments toward HCS (high carbon steel?) Patrick mentions the myriad of new "other" steels that are available in recent years which certainly come into consideration. There are so many different types of steel available today though. I am not sure we can even "scratch the surface" of those options without writing multiple volumes.

[ken hatch]

...

Hah, I do the same, this and setting hoops are both very enjoyable when time is very limited. I wonder if your finish stone is very similar to my Yaginoshima or maybe a bit finer (not the Nakayama, but the other one whose name escapes me). My shinden stone is very odd looking and that was the only way for me to keep it fairly reasonable in terms of price, you can probably still get a brick but wow, they will be out there, it's a great stone to use though, nice action and is often where I stop in normal use (the Nakayama is for times when an extra measure of sharpness is needed).

I built that sharpening bench so that I would run out of space for additional stones and that would be a barrier to new stones...we'll see if it works (not likely).



:D


...

Brian,

I'll bet it works as well as my promise :o. I was on So's web site looking earlier tonight.

I use two finish stones, I'm still trying to sort out which I like better, one is an old stock Takashima the other a Aiiwatani Kiita. They both do a good job and get to about the same place but have different feels. The Takashima is a little soft and chalky feeling while the Kiita is harder and slicker. Looking at the finished product my old eyes can't see any difference.

BTW, I spent a couple of hours this evening working on the sharpening bench and sharpening a couple of push chisels. One I finished on the Takashima the other on the Kiita, it would take a better man than I to tell the difference.

ken

[Brian Holcombe]

I am trying to understand this information. I have read a good deal of discussion on knife forums about how deceptive Rockwell "hardness" testing can be. The argument being that "hard" at some point can become brittle, resulting in chipping, whereas "tougher", but softer, may hold it's shape longer. Tougher may bend but not break.

Brian, I am wondering if you feel the Jnats (Japanese natural stones?) are capable of producing a superior edge in some regards? I think you were directing your comments toward HCS (high carbon steel?) Patrick mentions the myriad of new "other" steels that are available in recent years which certainly come into consideration. There are so many different types of steel available today though. I am not sure we can even "scratch the surface" of those options without writing multiple volumes.

Exactly, I'm not interested in having something that works ok with everything, rather I want two things which work very well together. That, plus the time factor of experience will produce superior results in what I need them to. I use HCS and workable alloys like Blue 1, 2 and Togo Kou. Blue Steels and Togo Kou are harder to work on natural stones, but they still work on them and produce excellent results. Experience on a stone is important, they reveal a lot as you put real time on them, you start to understand the personality of the stone and what works best for it.

Like most things there are many factors involved which drive the whole in a given direction, in my case it stems from ease of use in the context of how I use what I use. I often touch up an edge while I'm working, rather than using it to the point where it is dulled and cannot work I'll revisit the edge and touch it up, I do this for months and months before completely reworking a bevel from a low grit (like 1000 grit). With that said I like stones that I can just splash with water, build a quick slurry and start working them. It's hard for me to describe, but the natural stones I use have a nice feel to them in use, the slurry becomes useful rather than a nuisance. They remain mostly flat so I'm not constantly reflattening them, ect.

The effect is very similar to nice Arkansas stones, which are also enjoyable to use. I use Arkansas stones for inside curves and really enjoy them.

What originally caught my attention WTR Japanese Natural stones, all of the users talk about their use and their results in a positive way.


Brian,

I'll bet it works as well as my promise :o. I was on So's web site looking earlier tonight.

I use two finish stones, I'm still trying to sort out which I like better, one is an old stock Takashima the other a Aiiwatani Kiita. They both do a good job and get to about the same place but have different feels. The Takashima is a little soft and chalky feeling while the Kiita is harder and slicker. Looking at the finished product my old eyes can't see any difference.

BTW, I spent a couple of hours this evening working on the sharpening bench and sharpening a couple of push chisels. One I finished on the Takashima the other on the Kiita, it would take a better man than I to tell the difference.

ken

Haha, I'm sure thats true! I will likely just make more bench space. :D I keep raising the barrier to entry and it seems to have little effect.

Oh cool an Aiiwadani Kiita! Yours must be on the harder side? How do you compare them to your Nakayama? If I had to guess (and it would be just a guess since I have not used an Aiiwadani Kiita, I would guess that it's similar to my Yaginoshima Asagi, does the finish on the bevel look similar to that one in my photos, or more like that of the Shinden?

[ken hatch]

Exactly, I'm not interested in having something that works ok with everything, rather I want two things which work very well together.

...

Haha, I'm sure thats true! I will likely just make more bench space. :D I keep raising the barrier to entry and it seems to have little effect.

Oh cool an Aiiwadani Kiita! Yours must be on the harder side? How do you compare them to your Nakayama? If I had to guess (and it would be just a guess since I have not used an Aiiwadani Kiita, I would guess that it's similar to my Yaginoshima Asagi, does the finish on the bevel look similar to that one in my photos, or more like that of the Shinden?

Brian,

My wishes exactly, I want stones I can use with minimum fuss, that work reasonably fast on steel that is capable of getting very sharp. Long working time with a less than sharp iron is not on my wish list. My sharpening bench is less than a meter off the working end of the main work bench and is always set up. Work, step over and do a quick touch up, go back to work, repeat as needed.

The Aliwadani Kiita is almost razor hard. I expect the finish is not as nice as your Shinden but close. looking at the finish with the eye it has a nice smooth mirror finish with a slight haze and the Ji is well defined. Looking with a 10X lupe the Ha is not a near perfect matt like with the Nakayama but is close enough for most jobs.

ken

[Stanley Covington]

I am trying to understand this information. I have read a good deal of discussion on knife forums about how deceptive Rockwell "hardness" testing can be. The argument being that "hard" at some point can become brittle, resulting in chipping, whereas "tougher", but softer, may hold it's shape longer. Tougher may bend but not break.

Brian, I am wondering if you feel the Jnats (Japanese natural stones?) are capable of producing a superior edge in some regards? I think you were directing your comments toward HCS (high carbon steel?) Patrick mentions the myriad of new "other" steels that are available in recent years which certainly come into consideration. There are so many different types of steel available today though. I am not sure we can even "scratch the surface" of those options without writing multiple volumes.

Mike, allow me to insert some additional opinions.

Two points I would like to remind you of before I share my opinions:
1. Remember, what really determines the sharpness of a blade at the microscopic level where the cutting of wood gets done are the last few strokes on the last stone in the process. Everything before that is prep.
2. It is very difficult to objectively measure sharpness, and objectively measuring how long a blade remains "sharp" (whatever "sharp" means) is even more difficult. Anyone who tells you otherwise is blowing smoke up your skirt.

Let's compare synthetic and manmade stones a bit, sans the romance and history and Japanese words.

Modern manmade stones cut HC steel very, very well. This capability is extremely useful for wasting metal. Why do I believe that synthetic stones cut steel so effectively, and why are they more effective than natural stones, you may ask? The chemical particles used to make synthetic stones are measurably harder than the stone particles that comprise natural stones, so they cut steel more efficiently. In addition to being harder, the individual particles in synthetic stones have distinct, sharp corners, whereas the particles in natural stones (at least the Japanese version) tend to be rounder. Hard and angular versus soft and round. Oops, starting to sound a like a romance novel, perhaps "Love's Savage Secret?"

That reminds me of an old Japanese saying that goes something like this (not intended to be erotic): "A wife should be a stone to polish the blade that is her husband." Sharpening stones have a place deep in Japanese culture.

Anyway, back to the subject at hand.

While it is difficult to quantify the results, the process of sharpening a blade is straightforward. When you finish (vs "shape" or "prep") a blade on a any stone, whether synthetic or natural, the stone's particles plow a parallel row of furrows in the surface of the blade. The extreme leading edge of the finished blade viewed under a microscope looks quite jagged. The sharper a blade is, the thinner and more uniform this jagged edge will be. How long it will stay sharp is driven by how long it takes for the carbides exposed at this thin jagged edge to be torn off, and for the edge to round over. The sharpening stone can increase the amount of wood a blade can cut before dulling by creating furrows that tend to support the carbide particles and protect them from being torn off.

According to Ron Hock, and consistent with other studies I have seen, synthetic stone particles, being sharp and jagged, tend to plow furrows that are deep and V-shaped with walls sloped at relatively uniform angles, and narrow bottoms. The angled sides of these parallel furrows reflect light in a uniform manner, which explains perfectly why blades worked on synthetic stones easily achieve a mirror finish. By comparison, the rounder particles of natural stones cut shallower furrows with curved sides, and of course, rounded bottoms, diffusing reflected light, and producing a cloudy, misty appearance (at least ideally).

Appearance aside, I believe a high-quality high-carbon steel blade containing fine, evenly-distributed carbides as found in most hand-forged blades made of high-purity steel, and finished on a natural stone will stay sharper longer than the same blade finished on a synthetic stone of the same grit size. I have no hard data to support this opinion. But I believe the shallower, rounder furrows (or scratches) created by natural stones tend to support and hold in place the carbide crystals longer. This seems consistent with the SEM photographs I have seen, and feels consistent with how my blades perform when cutting wood.

I have been using natural Japanese finishing stones for a long time, but I don't care what mountain, or mine they came from, or what goofy name they have stamped on them. All I care about is how they perform during those last few strokes. I know the job is complete when the blade is free of visible scratches and the HC steel edge is a beautiful misty white color, and the low-carbon supporting steel is a matt grey. I don't have to test such a blade for sharpness, because I can sense it is very sharp. This is a very satisfying feeling, and one that is difficult (but not impossible) to obtain with a synthetic stone.

My advice is don't venture too close to the edge of this rabbit hole until you are truly ready to jump.

Stan

[Brian Holcombe]

Ken,

Interesting, they must have a big range in hardness. It seems the Yaginoshima Asagi are the same way, people use them for razors and for knives, which as you know are totally different, so my assumption is that there is a pretty wide range of hardness for some mines. The stone I have is fairly hard for how fast it cuts.

Sounds like you have one on the harder side, which is great. Is it easier to use than the Nakayama?

[Brian Holcombe]

Stan,

Thanks for commenting! That is a great post and describes much better the durable edge that I am experiencing with natural stones. I haven't tested them back to back per-say, but I might do so as it would be interesting.

[Normand Leblanc]

According to Ron Hock, and consistent with other studies I have seen, synthetic stone particles, being sharp and jagged, tend to plow furrows that are deep and V-shaped with walls sloped at relatively uniform angles, and narrow bottoms. The angled sides of these parallel furrows reflect light in a uniform manner, which explains perfectly why blades worked on synthetic stones easily achieve a mirror finish. By comparison, the rounder particles of natural stones cut shallower furrows with curved sides, and of course, rounded bottoms, diffusing reflected light, and producing a cloudy, misty appearance (at least ideally).
This is very interesting. Would you say that hard Arkansas stones, being natural stones, achieve the same kind of results?

I'm asking this because when I use a translucent Arkansas the surface finish looks like milky/cloudy compared to a strop with green compound where the result is shiny.

Normand

[Stanley Covington]

This is very interesting. Would you say that hard Arkansas stones, being natural stones, achieve the same kind of results?

I'm asking this because when I use a translucent Arkansas the surface finish looks like milky/cloudy compared to a strop with green compound where the result is shiny.

Normand

Normand:

It seems likely that Arkansas stones could achieve similar results if the particle size is small enough, and one is careful to prevent burnishing.

Stan

[Mike Holbrook]

Thanks Brian and Stan, this is the information I have been missing, which explains why and how natural stones may actually work to provide a very good or excellent final surface. Stan thanks for your extensive effort here to demystify these stones and the methodology to use to get the most from them. It all makes sense in relation to those other "truths" I have clung too in regard to sharpening. Stan thanks for warning me of the edge of the rabbit hole. I worry about that smoke up the skirt too, IMHO there is always a great deal more theory than fact. Even the best theory eventually seems to find variations that are even better....

I am wondering if a similar final result can be achieved with very hard ceramic stones like the Spydercos and green compound? I am guessing this is debatable. It may be that the nature of the fine but still sharp particles in these man made stones tends to cut or rub off softer steel vs pressing it between carbides?

Brian, I try to sharpen with a similar methodology to yours. I try to sharpen before my tool gets completely dull, at the time I can feel it slowing down/meeting more resistance..It takes less time and allows me to use a sharper blade more of the time for a similar amount of sharpening effort. Short breaks from the work do not interrupt ones flow whereas sharpening very dull tools can.

Thanks for the replies, sorry to steer a little off course Brian.

[ken hatch]

Mike, allow me to insert some additional opinions.

...(S)ynthetic stone particles, being sharp and jagged, tend to plow furrows that are deep and V-shaped with walls sloped at relatively uniform angles, and narrow bottoms. The angled sides of these parallel furrows reflect light in a uniform manner, which explains perfectly why blades worked on synthetic stones easily achieve a mirror finish. By comparison, the rounder particles of natural stones cut shallower furrows with curved sides, and of course, rounded bottoms, diffusing reflected light, and producing a cloudy, misty appearance (at least ideally).

Appearance aside, I believe a high-quality high-carbon steel blade containing fine, evenly-distributed carbides as found in most hand-forged blades made of high-purity steel, and finished on a natural stone will stay sharper longer than the same blade finished on a synthetic stone of the same grit size. I have no hard data to support this opinion. But I believe the shallower, rounder furrows (or scratches) created by natural stones tend to support and hold in place the carbide crystals longer. This seems consistent with the SEM photographs I have seen, and feels consistent with how my blades perform when cutting wood.

... I know the job is complete when the blade is free of visible scratches and the HC steel edge is a beautiful misty white color, and the low-carbon supporting steel is a matt grey. I don't have to test such a blade for sharpness, because I can sense it is very sharp. This is a very satisfying feeling, and one that is difficult (but not impossible) to obtain with a synthetic stone.

My advice is don't venture too close to the edge of this rabbit hole until you are truly ready to jump.

Stan

Stan,

That has been my understanding and it has proven to be true (at least the sharp part) in practice. I have often said "shiny is not necessarily sharp". Sharp is a fine, can be almost matt, scratch pattern that holds up after the first contact with wood. Good Ark stones will produce the same fine matt finish, I've just recently jumped down the rabbit hole but I'm finding the same is true with JNats.

ken

[Kees Heiden]

Normand:

It seems likely that Arkansas stones could achieve similar results if the particle size is small enough, and one is careful to prevent burnishing.

Stan

How do you prevent burnishing on a fine Arkansas and why would you?

[Normand Leblanc]

How do you prevent burnishing on a fine Arkansas and why would you?

If someone could explain what burnishing is it would be appreciated. Must be my frenchglish!
Normand

[Pat Barry]

Mike, allow me to insert some additional opinions.

Two points I would like to remind you of before I share my opinions:
1. Remember, what really determines the sharpness of a blade at the microscopic level where the cutting of wood gets done are the last few strokes on the last stone in the process. Everything before that is prep.
2. It is very difficult to objectively measure sharpness, and objectively measuring how long a blade remains "sharp" (whatever "sharp" means) is even more difficult. Anyone who tells you otherwise is blowing smoke up your skirt.

Let's compare synthetic and manmade stones a bit, sans the romance and history and Japanese words.

Modern manmade stones cut HC steel very, very well. This capability is extremely useful for wasting metal. Why do I believe that synthetic stones cut steel so effectively, and why are they more effective than natural stones, you may ask? The chemical particles used to make synthetic stones are measurably harder than the stone particles that comprise natural stones, so they cut steel more efficiently. In addition to being harder, the individual particles in synthetic stones have distinct, sharp corners, whereas the particles in natural stones (at least the Japanese version) tend to be rounder. Hard and angular versus soft and round. Oops, starting to sound a like a romance novel, perhaps "Love's Savage Secret?"

That reminds me of an old Japanese saying that goes something like this (not intended to be erotic): "A wife should be a stone to polish the blade that is her husband." Sharpening stones have a place deep in Japanese culture.

Anyway, back to the subject at hand.

While is is difficult to quantify the results, the process of sharpening a blade is straightforward. When you finish (vs "shape" or "prep") a blade on a any stone, whether synthetic or natural, the stone's particles plow a parallel row of furrows in the surface of the blade. The extreme leading edge of the finished blade viewed under a microscope looks quite jagged. The sharper a blade is, the thinner and more uniform this jagged edge will be. How long it will stay sharp is driven by how long it takes for the carbides exposed at this thin jagged edge to be torn off, and for the edge to round over. The sharpening stone can increase the amount of wood a blade can cut before dulling by creating furrows that tend to support the carbide particles and protect them from being torn off.

According to Ron Hock, and consistent with other studies I have seen, synthetic stone particles, being sharp and jagged, tend to plow furrows that are deep and V-shaped with walls sloped at relatively uniform angles, and narrow bottoms. The angled sides of these parallel furrows reflect light in a uniform manner, which explains perfectly why blades worked on synthetic stones easily achieve a mirror finish. By comparison, the rounder particles of natural stones cut shallower furrows with curved sides, and of course, rounded bottoms, diffusing reflected light, and producing a cloudy, misty appearance (at least ideally).

Appearance aside, I believe a high-quality high-carbon steel blade containing fine, evenly-distributed carbides as found in most hand-forged blades made of high-purity steel, and finished on a natural stone will stay sharper longer than the same blade finished on a synthetic stone of the same grit size. I have no hard data to support this opinion. But I believe the shallower, rounder furrows (or scratches) created by natural stones tend to support and hold in place the carbide crystals longer. This seems consistent with the SEM photographs I have seen, and feels consistent with how my blades perform when cutting wood.

I have been using natural Japanese finishing stones for a long time, but I don't care what mountain, or mine they came from, or what goofy name they have stamped on them. All I care about is how they perform during those last few strokes. I know the job is complete when the blade is free of visible scratches and the HC steel edge is a beautiful misty white color, and the low-carbon supporting steel is a matt grey. I don't have to test such a blade for sharpness, because I can sense it is very sharp. This is a very satisfying feeling, and one that is difficult (but not impossible) to obtain with a synthetic stone.

My advice is don't venture too close to the edge of this rabbit hole until you are truly ready to jump.

Stan
Very interesting theory Stan. I think you have done a good job of explaining the process and result. I do find your conclusion about round particles leading to the misty white color and grey matte finish or not because my initial thought would be that sharper points would lead to finer scratches and thus the milky appearance - who knows without a SEM study? I have a question though and it ties in with Brian's initial postings and or video and your description. Do you tend to use the final stone with a slurry built up on it or just clean with water. I recall Brian mentioning that he develop a slurry although I don't recall if this was for the coarse work or the final steps.

[ken hatch]

Ken,

Interesting, they must have a big range in hardness. It seems the Yaginoshima Asagi are the same way, people use them for razors and for knives, which as you know are totally different, so my assumption is that there is a pretty wide range of hardness for some mines. The stone I have is fairly hard for how fast it cuts.

Sounds like you have one on the harder side, which is great. Is it easier to use than the Nakayama?

Brian,

I can't answer ease of use for the Nakayama just yet. It is too new and I'm still getting use to it but I just sharpened one of my #2 White Steel push chisels using the Kiita and finishing on the Nakayama. The Kiita finish was more than adequate with no lined up scratches to the edge, the chisel was good for anything you could ask of it. The follow up with the Nakayama just refined the matt finish, I expect a slightly sharper and longer lasting edge but in use I doubt there would be a noticeable difference.

Enough fun, time for the monkey suit and strapping my butt to a dark box for several hours.

ken

[Kees Heiden]

If someone could explain what burnishing is it would be appreciated. Must be my frenchglish!
Normand

Burnishing happens for example when you slide a ball (for example a sharpening grit particle) over a steel surface (the chisel edge) with enough pressure to exceed the yield strength of the material. When you exceed the yield strength, the material doesn't react elasticy anymore, it deforms permanently. In other words, the deformations don't jump back after the passage of the ball, they are permanent.

If the grit particle has sharp edges or corners, then it works with a cutting action, it makes a groove and really removes material. If the grit particle is rounded (and it is hard enough) then it also makes a groove but the material isn't removed, it is smeared aside. With a bit of luck you smear the tops of the grooves into the valleys, and thus make the surface smoother. You also make it harder.

I don't know if that really happens when you use a fine Arkansas stone that hasn't been dressed for a long time. I also don't know if it desirable or not. In theory it doesn't sounds too bad, so I am curious if Stanley has other information.

I don't think this happens with synthetic waterstones, because the surface of the stone is continually refreshed, so you always have fresh grit particles. With all the talk about slurry building I also think burnishing doesn't really happen with natural water stones, but I could be wrong. The grit particles of natural waterstones are not very sharp to begin with. But when you grab an old, dished, black Arkansas from a long forgotten toolbox, then the chance that it hasn't been dressed in a loooong time is likely, so burnishing could be real.

Edit: I think there is another kind of burnishing which happens when the stone is fully loaded with steel swarf and doesn't cut anymore.

[Brian Holcombe]

Thanks Brian and Stan, this is the information I have been missing, which explains why and how natural stones may actually work to provide a very good or excellent final surface. Stan thanks for your extensive effort here to demystify these stones and the methodology to use to get the most from them. It all makes sense in relation to those other "truths" I have clung too in regard to sharpening. Stan thanks for warning me of the edge of the rabbit hole. I worry about that smoke up the skirt too, IMHO there is always a great deal more theory than fact. Even the best theory eventually seems to find variations that are even better....

I am wondering if a similar final result can be achieved with very hard ceramic stones like the Spydercos and green compound? I am guessing this is debatable. It may be that the nature of the fine but still sharp particles in these man made stones tends to cut or rub off softer steel vs pressing it between carbides?

Brian, I try to sharpen with a similar methodology to yours. I try to sharpen before my tool gets completely dull, at the time I can feel it slowing down/meeting more resistance..It takes less time and allows me to use a sharper blade more of the time for a similar amount of sharpening effort. Short breaks from the work do not interrupt ones flow whereas sharpening very dull tools can.

Thanks for the replies, sorry to steer a little off course Brian.

Mike, I believe that is why George tends to wear in his green compound. I don't want to speak for George on the off chance that I am misremembering, but maybe he will comment.

I never mind if my topics go well of course, it's part of the fun.


Very interesting theory Stan. I think you have done a good job of explaining the process and result. I do find your conclusion about round particles leading to the misty white color and grey matte finish or not because my initial thought would be that sharper points would lead to finer scratches and thus the milky appearance - who knows without a SEM study? I have a question though and it ties in with Brian's initial postings and or video and your description. Do you tend to use the final stone with a slurry built up on it or just clean with water. I recall Brian mentioning that he develop a slurry although I don't recall if this was for the coarse work or the final steps.

Pat, WRT the slurry, I slurry all of the finish stones. However I would like to add some comments.

With a medium or rough grit stone they build their own slurry very quickly, so in order to maintain a flat bevel on a chisel or something of that sort I let them build their own slurry. If you have ever used an India stone the effect is somewhat similar.

With medium fine or fine stones they're usually slow to slurry in my experience, so you can let them build their own slurry but I prefer to speed up the process and build one, that being said the finer the stone the finer the slurry. Most people would probably not describe what is happening on my Nakayama asagi as a 'slurry' at first glance, but it is one it's just incredibly light.


Brian,

I can't answer ease of use for the Nakayama just yet. It is too new and I'm still getting use to it but I just sharpened one of my #2 White Steel push chisels using the Kiita and finishing on the Nakayama. The Kiita finish was more than adequate with no lined up scratches to the edge, the chisel was good for anything you could ask of it. The follow up with the Nakayama just refined the matt finish, I expect a slightly sharper and longer lasting edge but in use I doubt there would be a noticeable difference.

Enough fun, time for the monkey suit and strapping my butt to a dark box for several hours.

ken

Ahh, the Nakayama took some time for me to get a handle on, just one word of caution (or to be aware of) it's the only stone I've had that is so hard that it actually became convex from regularly use with a 1200 atoma, so I check it for flatness now every so many uses. It's a handy stone to have if you need that extra fineness. I use it on my sushi knife and that thing zips through fish. I bet if you used it on Steve's smoother it would turn a piece of cypress into a mirror.

[Patrick Chase]

According to Ron Hock, and consistent with other studies I have seen, synthetic stone particles, being sharp and jagged, tend to plow furrows that are deep and V-shaped with walls sloped at relatively uniform angles, and narrow bottoms. The angled sides of these parallel furrows reflect light in a uniform manner, which explains perfectly why blades worked on synthetic stones easily achieve a mirror finish. By comparison, the rounder particles of natural stones cut shallower furrows with curved sides, and of course, rounded bottoms, diffusing reflected light, and producing a cloudy, misty appearance (at least ideally).

Appearance aside, I believe a high-quality high-carbon steel blade containing fine, evenly-distributed carbides as found in most hand-forged blades made of high-purity steel, and finished on a natural stone will stay sharper longer than the same blade finished on a synthetic stone of the same grit size. I have no hard data to support this opinion. But I believe the shallower, rounder furrows (or scratches) created by natural stones tend to support and hold in place the carbide crystals longer. This seems consistent with the SEM photographs I have seen, and feels consistent with how my blades perform when cutting wood.


The degree to which this is true is going to depend on both alloy and heat-treatment, as it's basically a stress-concentration argument in disguise, and therefore largely a matter of toughness. Japanese tools are an extreme example, as HCS tempered to Rc64-65 is extremely brittle stuff (low toughness as measured by Chapy C-notch scores etc). I therefore wouldn't be surprised if such tools' wear life is indeed sensitive to "furrow geometry" as you describe. In that sense natural waterstones may be very well matched to Japanese blades.

EDIT: It's probably worth noting that Ron Hock also uses HCS at higher-than-typical hardness (he tempers O1 to Rc62, vs common practice of ~Rc58-59 in Western tools), so his blades would probably also be unusually sensitive to notching.

[george wilson]

I repeat again,the maximum hardness for 01 is supposed to be RC 60. And,I consider that to be too hard for maximum edge retention. Over many years and many antique plane irons that I tried,back when you could get then for $2.00,I found that the ones that would hold an edge the longest could barely be files with a new,fine tooth file. This indicates a hardness of about 55 RC. Of course,these were carbon steel. However I have made very many cutting tools from 01. The ones that were too hard just would not hold a good edge. The microscopic cutting edge would break off.

[Patrick Chase]

I repeat again,the maximum hardness for 01 is supposed to be RC 60. And,I consider that to be too hard for maximum edge retention. Over many years and many antique plane irons that I tried,back when you could get then for $2.00,I found that the ones that would hold an edge the longest could barely be files with a new,fine tooth file. This indicates a hardness of about 55 RC. Of course,these were carbon steel. However I have made very many cutting tools from 01. The ones that were too hard just would not hold a good edge. The microscopic cutting edge would break off.

I agree with you that HCS tempered to anything over ~Rc60 is prone to chipping, but Hock clearly states in his book that he aims for Rc62. He also explicitly recommends tempering HCS to 325F (http://hocktools.com/tech-info/diyht.html), which is consistent with Rc62.

I should have been clearer that those Japanese tools up in the mid Rc60s are "white steel" and not O1, though it's low-alloy HCS either way.

[Stanley Covington]

Very interesting theory Stan. I think you have done a good job of explaining the process and result. I do find your conclusion about round particles leading to the misty white color and grey matte finish or not because my initial thought would be that sharper points would lead to finer scratches and thus the milky appearance - who knows without a SEM study? I have a question though and it ties in with Brian's initial postings and or video and your description. Do you tend to use the final stone with a slurry built up on it or just clean with water. I recall Brian mentioning that he develop a slurry although I don't recall if this was for the coarse work or the final steps.

The cause of the "milky" appearance was one proposed by Ron Hock on his blog, and is based on SEM photos. I have since confirmed it with a Japanese sword polisher with a somewhat scientific mindset. It is also consistent with studies I have read on, of all things, piano finishes, and how the shape of the girt and direction of the polishing (circular versus linear) can greatly impact not only the shininess, but even the perceived color of the black lacquer. But I have not done scans myself, so I present it only as a theory.

The slurry is absolutely essential, especially for the final steps. And you should gradually decrease pressure.

Stan

[John Kananis]

I use it on my sushi knife...

OK, that's it; you make sushi too - I'm in Jersey; I'm coming by to hang out... :-)

[Patrick Chase]

OK, that's it; you make sushi too - I'm in Jersey; I'm coming by to hang out... :-)

Nah, he merely said he has a sushi knife. Actual use of said knife hasn't been established. Tool-junkie-ism isn't limited to woodworking you know :-).

[John Kananis]

Nah, he merely said he has a sushi knife. Actual use of said knife hasn't been established. Tool-junkie-ism isn't limited to woodworking you know :-).

Tell me abut it, you should see my electronics labs, lol. Still want sushi, haha.

[Brian Holcombe]

http://i27.photobucket.com/albums/c181/SpeedyGoomba/A3AF5D68-F2DD-4C29-B3E8-B583D608F1EC_zps3dkp304l.jpg

LOL, John! ...My sushi making is hit or miss, my speciality is truly barbecue ribs, steaks and burgers.

Sashimi is fairly easy, good fish and my cutting work is fairly reliable, but I'm fine tuning my rice recipe (I realize that is sort of the life long goal of sushi making).

[John Kananis]

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

[Mike Holbrook]

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 leave more residue on the stone with more of a "greasy" texture. The steel seems to smear across the surface of the stones. My Sigma Power Select 2's seem to work more like I think the jnats work. Steel seems to attach to the swarf more than the stone.

I use the green compound on MDF like George and his theory of the larger particles embedding in wood or MDF or breaking up after use seems probable from my experience as well. I believe Rob Lee supported that theory in another thread. I have wondered if the smeared steel residue on the fine Spyderco stone worked something like the MDF with embedded compound. The smeared steel essentially dulling the sharp particles.

I thought burnishing implied the moving of metal along an edge with a "burnisher", as used to make a feather edge on a scraper. If burnishing can make a feather edge on a scraper, I am wondering if it might fill in between the microscopic grooves in the edge as well.

I seem to chase a "wire" edge with the fine Spyderco that the green compound might be removing.

[Kees Heiden]

I'v read that the fine Spyderco's also have a burnishing action. Likewise I read an old comment from David Weaver where he wrote about the very hard Japanese finishers, also working more like a burnisher then a cutter.

Those things are never 100% one or the other. I still see plenty of black stuff appearing on my Arkansas translucent, but it sure doesn't feel like it is cutting.

I am still very curious to hear a further explanation from Stanley that burnishing should be avoided when using oil 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 :D


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! :D 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 :eek:

[Stewie Simpson]

Do kalofagas and souvlaki count? I love both!

Hehe, have yanagi-ba, will travel :D



Now I know where I'm stopping if travel to GA! :D 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/about-japanese-natural-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.



http://2.bp.blogspot.com/-OAoUd1CyGVQ/TljHGJuk6kI/AAAAAAAAMJc/ZsOvqXdaJfg/s640/gora3-01.jpg (http://2.bp.blogspot.com/-OAoUd1CyGVQ/TljHGJuk6kI/AAAAAAAAMJc/ZsOvqXdaJfg/s1600/gora3-01.jpg)

[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 :D 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 :eek:.

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

[Stanley Covington]

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.

Patrick:

You bring up some very astute points.

I should clarify what I mean when talk about burnishing being a bad thing in some cases.

The first point I should clarify is that the same thing can happen on almost any stone, but I think it happens easiest on novaculite stones because their pores tend to clog, especially when the stone is used dry, or when the water dries, or lubricating properties of the oil decrease. You know what I mean: "The glaze."

I agree that burnishing is unlikely to occur if the stone is kept lubricated.

Second point. You are right about the pressure. But pressure is a relative thing, so if someone applies a lot of speed and pressure to a blade on a dry stone, and glaze develops, the pressure applied to a very small area on top of a ridge of glaze (as seen from a bacteria's eye view) can, in my opinion, create enough heat to soften the steel locally. I believe this occurs most easily at the extreme points on the cutting edge where there is not much backing metal to act as a heat sink.

If we scale the phenomenon up a bit, perhaps it will make more sense. Have you ever seen a large slab of concrete being dragged over another slab of concrete as it is suspended by a crane? The contact of course is not even, and where the two slabs meet, gouges are cut into both slabs, and dust and smoke flies. The slabs themself never heat up, but the aggregate gouged out of their surfaces is steaming and very hot.

But as I said before, I have no hard evidence.

Regards,

Stan

[Stanley Covington]

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

Warren:

My armchair theory is just as valid as your armchair theory. Mine has a couple of engineering degrees and real-world experience in structural design padding it out when the discussion involves materials science.

I for one am sincerely eager to learn from your real world experience, Warren. Please take the time and make the effort to add something to the discussion instead of just throwing cold water on everything.

Thank you in advance.

Stan

[Kees Heiden]

This discussion will probably remain armchair theorising for us. It's just not doable for us to really know what happens down there at the atomic level. Weird things can and do happen on such a small scale.

I'm glad I have now a better idea about your former comment on burnishing. Treating my Arkansas stone withe reasonable care, using oil and wiping it clean after work, I don't see it glazing up too soon. But because I don't dress the stone or scrub it with diamond plates or whatever, and because these stones don't release grit easilly, I am sure the grit particles will be rather rounded. So some plastic deformation is inevitable. By the way, sharp grit works with a mixed action of cutting and deformation too. Those grit particles are not like rows of neat chisel edges lined up at a 45 degree cutting angel next to each other. They are tumbled about and scrape and cut and plow all at the same time. Sharp grit certainly works a lot quicker then rounded grit of course, but tends to leave deeper trenches at the same grit rating.

Glazing btw is in large part a matter of a stone filled up with steel swarf. So the action of the grit particles is seriously hampered by all that swarf clogging up the pores of the stone and the steel will heat up much quicker.

It was fun to watch Brian's approach to sharpening Japanese chisels and the care he puts in not just creating a very sharp edge but also into the appearance of the bevel. I am afraid he would turn away aghast from my Japanese chisels. They look awfull. I treat them like western chisels, do the primary on a fine India, I might polish that up a bit with a Washita and then do a small secundairy on the translucent Arkansas, followed by a stropping on a well worn in Autosol treated strop. If I nick a corner of a blade accidentally, I am not afraid to use a dry grinder to bring it back in shape :eek:. Nonetheless I am very happy with these chisels. They are very well made, I like the laminated construction and they sure do get very sharp very easilly, and keep that edge for a good while.

[Brian Holcombe]

Theory or otherwise it is a great discussion and certainly interesting to think about.

Kees, thanks for the comment, I may well turn aghast as you say :p Be forewarned, if you decide to create a nice kasumi finish on those chisels it will be hard to part with in future sharpening sessions.

[Warren Mickley]

I watched Brian's video a second time and thought I would make a few comments.

I give Brian high marks for his technique and for his discernment. I think these things are actually more important than a workers equipment; without these the finest stones are not much use. In talking about technique we need to look at not only the manner in which something is done, but the quality of execution. Brian's motions are all smooth, very clean and crisp, without clumsiness or extra little quirks. Unlike many others, when he says he hones at 30 degrees it is apparent that he is actually doing so.

By discernment I mean having a feeling for what is going on with the stone. As examples: knowing when the stone is cutting well, being able to feel when the stone has done it job of making a nice edge or removing roughness from the previous stone, knowing when the edge needs work, knowing which stone is appropriate and the like. Rather than just going through the motions and following a recipe, Brian seems fully involved with all his senses.

One thing I was tickled to see was that Brian let the plane iron overhang the edge on both sides. This is something I have preached on forums for about a decade without seeing many pick up on it. This enables one to manage the wear on the stone. It takes skill to balance the iron like this and to take the rapid strokes that Brian takes. Some encourage beginners to keep everything locked and sway the whole body. Brian's motion is more complicated, but so smooth it looks simple. One thing I wondered about was the short stokes, perhaps only one third the length of the stone. I use rapid strokes like Brian, but nearly the full length of the stone.

Brian, you ground the iron at a shallow angle and only honed a small portion of the bevel; I wondered if this was usual for you or if some tools were full flat bevel.

[Brian Holcombe]

Thanks Warren! I appreciate the comments. I actually overhang the stone after reading one of your posts recommending the technique some years back, I find it very easy to create and maintain a light camber using that method.

All of my Japanese tools are full bevel but my western tools are a mix.

[Patrick Chase]

I'm glad I have now a better idea about your former comment on burnishing. Treating my Arkansas stone withe reasonable care, using oil and wiping it clean after work, I don't see it glazing up too soon. But because I don't dress the stone or scrub it with diamond plates or whatever, and because these stones don't release grit easilly, I am sure the grit particles will be rather rounded. So some plastic deformation is inevitable. By the way, sharp grit works with a mixed action of cutting and deformation too.

Technically speaking, cutting *is* deformation.

You can't cleave a material without locally exceeding its ultimate tensile strength, and to do that you must have first exceeded the yield strength. In an extremely brittle material those values are very close to each other and so not much plastic deformation happens before fracture, but for the sorts of metals we're talking about here there's all sorts of deformation going on.

The key figure of merit is the amount of power dissipated via plastic deformation per unit volume material removed. In general sharper/harder abrasives do better in that respect than dull ones. If this sounds familiar, that's because it's *exactly* the reason why friable AlOx grinding wheels are "cooler running" than ones with hard binders, and why CBN and diamond are much cooler still.

Two offhand remarks:

1. Earlier in the thread Stanley brought up scratch geometry/sharpness and argued that SiOx is better because it leaves smoother/rounder scratches. Unfortunately this is a case where you can't have your cake and eat it too. JNats leave rounded-off scratches precisely because the abrasive isn't particularly sharp and isn't cleaving the metal cleanly and there's lots of plastic deformation happening.

2. On a related note, if heating via plastic deformation were really an issue for hand honing, then natural waterstones would be a far from ideal way to address it. If you're really worried about plastic deformation then you want the sharpest, cleanest-cutting abrasives possible, and that means you should be using diamonds. IMO it isn't really an issue, though, and therefore isn't a valid reason to use diamonds for hand-honing.

On a more practical point, my own experiences dovetail with Warren's last comment: What you use matters less than how you use it (provided the steel and the medium aren't glaringly mismatched - you're never going to get good results with CPM-10V on any SiOx stone, for example). There are certainly speed/convenience/cost tradeoffs between media of course.

[Phil Mueller]

Brian, somehow I've missed your sharpening video (per Warren's post) and can't find it on your blog or within this thread. Can you repost, or link me in the right direction?
Thanks!

[Brian Holcombe]

Certainly, here is the video;


https://youtu.be/DZ8n6Xfdj1o

I work the try plane iron in this video, I may do another with Japanese tools.

[Patrick Chase]

Those grit particles are not like rows of neat chisel edges lined up at a 45 degree cutting angel next to each other.

What, you don't hone exclusively using Trizact (http://www.leevalley.com/US/wood/page.aspx?p=66268&cat=1,43072)?

Or better yet *diamond* Trizact, at only $230 or so for a 1x60 belt.

[Stanley Covington]

Two offhand remarks:

1. Earlier in the thread Stanley brought up scratch geometry/sharpness and argued that SiOx is better because it leaves smoother/rounder scratches. Unfortunately this is a case where you can't have your cake and eat it too. JNats leave rounded-off scratches precisely because the abrasive isn't particularly sharp and isn't cleaving the metal cleanly and there's lots of plastic deformation happening.


I think you misunderstood my post. Synthetic stones cut steel faster because of their abrasive particle's very pointed geometry and the particle's relative hardness. I like this and think it is superior because it saves time, and because synthetic stones cost less. I did not write that the particles have rounded geometry.

Natural stones of the sedimentary type mined in Japan ( but not just Japanese sources) are typically made of more friable particles with rounder geometry. They clearly cut and polish less aggressively, but the nature of the scratches they produce results in more dispersed light refraction and a consequently different appearance to the steel in the case of the higher quality finishing stones and stone veneers used for polishing swords. This is well documented and standard procedure in the sword polishing industry. Of course, it applies to tool blades to some degree. I thought this point too was very clearly presented in my previous posts. Curious...

I am not "having my cake and eating too." I have repeatedly mentioned the trade offs, but since careful reading is a rare skill at SC, I will state it very clearly, again: Compared to synthetic stones, high- quality natural Japanese finishing stones are less efficient at wasting metal. They take more time to finish a blade. They cost a lot more. But in my opinion, the results are more attractive and the cutting edge retains sharpness a little longer. I am not alone in this opinion, although those of you without practical experience using them may doubt me. That is your loss.

Please experiment for yourself with a high-quality stone and a high- quality blade and you will immediately understand.

[Mike Holbrook]

"It's just not doable for us to really know what happens down there at the atomic level. Weird things can and do happen on such a small scale."

Except everything apparently happens at the sub atomic level chemically. Chemistry, sometimes called the central science because it bridges other natural sciences including; physics, geology and biology, tries to define the composition, structure, properties and change of matter.

If we are to believe physicists the relationship between matter and energy at the quantum level gets a "little" complicated. The further we look into sub atomic particles the more space we find without actually finding "solid" matter. Energy seems to be the most "solid" sub atomic component. Maybe we will compose a mathematical formula, if one exists, that will define exactly what happens at the sub atomic level, maybe not. The point being that until we do the jury is still out and it is all theory. Unless we come up with "THE" formula on this forum everyones theories, taken from our own experiences, have value.

No one has "the" one correct answer with all perfectly correct variables, calculated for all conceivable conditions, so why waste our time arguing about it?

[Stewie Simpson]

Brian; after watching your video I took note of the additional effort required by you to work your closely set double iron tri plane; the following blog entry by Richard Maguire should be of some interest. http://www.theenglishwoodworker.com/cap-iron-fatigue/

I had a bit of a chuckle when I read Richards subtle response to Kees objection.

Kees van der Heiden March 3rd, 2016 (http://www.theenglishwoodworker.com/cap-iron-fatigue/#comment-84918) Sorry, you are wrong Richard! https://s.w.org/images/core/emoji/72x72/1f609.png
The trick is to set the capiron at an appropriate distance. Too close and planing becomes real hard work. Too far and it isn’t helpfull.
Especially in the try-plane fase of dressing a board, the capiron is very valuable. Sure, don’t set it too close, but set it close it enough that it prevents disasters, deep tearout that takes ages to remove and makes you go beyond layout lines. On a troublesome board this won’t give you a blemish free surface, that’s the smoothers job, but it sure beats deep tearout.
A capiron beveled to no more then 45 degrees, set at an appropriate distance from the edge is really not so bad in the aspects you mention. Extra resistance makes you feel that the capiron does its job. If you really want to know what hard work is, try a plane with a high cutting angle.
Reply (http://www.theenglishwoodworker.com/cap-iron-fatigue/?replytocom=84918#respond)

http://www.gravatar.com/avatar/20c50688645d8ae5bd617aabae82a7bd?s=80&d=mm
Richard Maguire March 3rd, 2016 (http://www.theenglishwoodworker.com/cap-iron-fatigue/#comment-84923) Hmm… so ‘wrong’, yet you agree. A cap iron that’s doing something adds resistance.
Not everyone’s aware of this and it’s an essential mechanic to understand.

[Brian Holcombe]

Hi Stewie,

The work I typically do with the Try plane is to true a panel or board prior to finish planing. Tear out at that juncture causes a substaintial increase in the time spend on the finish plane. So it makes the planing easier but the work harder.

I realize that I was jointing the edge of a test board, which is also work I do with the try plane.

It's funny that you bring that up, I was just reading that article this morning.

[Stewie Simpson]

Brian; you have probably viewed Richard Maguire's previous video on his blog site; http://www.theenglishwoodworker.com/cap-irons-tear-out-video/

Within the comments section; Richard offers some clear insight on his approach to the use of cap irons.

Richard May 11th, 2015 (http://www.theenglishwoodworker.com/cap-irons-tear-out-video/#comment-73394)

Warren; don’t worry, I left the concerns of tear out behind with puberty. As David said, this is a great topic worth further discussion, but is beyond the scope of this video and this post. I aim for clarity on subjects for my audience so try to cover one point at a time, but I have mentioned previously that I don’t simply class a plane by it’s length but how I’ve chosen to set it up for use. 90% of my work is finished off the try which is set up closely to my smoother (I don’t do any of the wispy, thin gravity defying shavings).

If I’m hogging off material however then I won’t concern myself with the cap iron, I don’t have problems with tear out since I’ll read the wood, make judgement and alter my approach on the fly, but that’s a whole other subject. I’ll not just judge every piece of wood as being the same, I’m working it by hand so I can respond as a human.

When I look for the positive point in what you’ve written I do find that we’re almost on the same page… almost.

[Patrick Chase]

The work I typically do with the Try plane is to true a panel or board prior to finish planing. Tear out at that juncture causes a substaintial increase in the time spend on the finish plane. So it makes the planing easier but the work harder.

I think that this is a key point, and one that I've tried to bring up a few times in various threads but probably haven't expressed as well as you did.

IMO jointer/try planes benefit even more from a close-set cap iron than do smoothers. As you say you don't want to leave much tearout behind for the smoother, or else you have to take a lot of passes and productivity becomes an issue. At the same time jointing usually requires a moderate amount of material removal, so productivity also demands relatively thick shavings with a wide blade. The former means that you can't mitigate tearout by reducing shaving thickness, and both taken together make high cutting angles undesirable unless you're very strong and/or masochistic (while the cap iron does increase cutting forces, it is my experience that it does so less than does increasing the cutting angle enough to get equivalent tearout performance).

Smoothing is much less constrained, again IMO. You can take thinner shavings, which both mitigates tearout directly and makes high cutting angles less onerous, which in turn opens the door to further tearout mitigation.

If I were only allowed to use a close-set cap iron on one plane the choice would be easy: #7.

EDIT: To be completely clear, I use my planes with the cap iron set a bit back (~1/64") from the edge most of the time. For the most part I only advance it to a tighter setting for troublesome grain. My point above is that when I do so with a smoother I usually have other (less desirable but still viable) options, whereas with the jointer it's more of an a**-saver.

[Patrick Chase]

http://www.gravatar.com/avatar/20c50688645d8ae5bd617aabae82a7bd?s=80&d=mm
Richard Maguire March 3rd, 2016 (http://www.theenglishwoodworker.com/cap-iron-fatigue/#comment-84923) Hmm… so ‘wrong’, yet you agree. A cap iron that’s doing something adds resistance.
Not everyone’s aware of this and it’s an essential mechanic to understand.



This is inarguably true in the "there is no free lunch" sense - obviously if the cap iron is doing work on the wood then it must add some incremental resistance.

With that said I think that Richard's reply is based on a creative (and perhaps intentional) misinterpretation of what Kees said. Kees didn't claim that the cap iron adds no incremental resistance, he merely pointed out that the setting is a tradeoff between resistance and tearout mitigation, which is an equally inarguable truth, again in the "no free lunch" vein. The real questions are "how much resistance does it add" and "how does it compare in that respect to other means of tearout mitigation"?

The second (and more important) part of Kees' argument addresses those questions. He argues that for any given amount of desired tearout mitigation, a low-angle blade with a close-set cap iron adds significantly less cutting resistance than does a single iron (no cap iron) pitched at a sufficiently high angle to achieve the same results. While that's clearly open to debate, it's consistent with my experience. That's also why I think that close-set cap irons are *very* useful indeed on jointers.

[Kees Heiden]

Indeed!

The "You are wrong" was a catchy title of course. Maybe a bit too catchy?

[Brian Holcombe]

Brian; you have probably viewed Richard Maguire's previous video on his blog site; http://www.theenglishwoodworker.com/cap-irons-tear-out-video/

Within the comments section; Richard offers some clear insight on his approach to the use of cap irons.

Richard May 11th, 2015 (http://www.theenglishwoodworker.com/cap-irons-tear-out-video/#comment-73394)

Warren; don’t worry, I left the concerns of tear out behind with puberty. As David said, this is a great topic worth further discussion, but is beyond the scope of this video and this post. I aim for clarity on subjects for my audience so try to cover one point at a time, but I have mentioned previously that I don’t simply class a plane by it’s length but how I’ve chosen to set it up for use. 90% of my work is finished off the try which is set up closely to my smoother (I don’t do any of the wispy, thin gravity defying shavings).

If I’m hogging off material however then I won’t concern myself with the cap iron, I don’t have problems with tear out since I’ll read the wood, make judgement and alter my approach on the fly, but that’s a whole other subject. I’ll not just judge every piece of wood as being the same, I’m working it by hand so I can respond as a human.

When I look for the positive point in what you’ve written I do find that we’re almost on the same page… almost.


http://i27.photobucket.com/albums/c181/SpeedyGoomba/33970C03-5DBB-4C52-97BC-646133CCB204_zpsdpqcx5av.jpg

http://i27.photobucket.com/albums/c181/SpeedyGoomba/5222C69D-6952-4754-90CD-CF0044542DB7_zpsaoltxsvs.jpg

[Warren Mickley]

Placing the cap iron is an art. If it is placed appropriately for the work at hand the plane is less work to push because cutting cleanly takes less effort than creating tear out.

[Patrick Chase]

Placing the cap iron is an art. If it is placed appropriately for the work at hand the plane is less work to push because cutting cleanly takes less effort than creating tear out.

Warren, I wouldn't question your expertise, but doesn't this depend on extent? if you have a very localized grain reversal causing a narrow band of tearout, then in my experience the increase in cutting force is modest relative to the overall effort. In contrast you generally pay "full price" for mitigations (cap iron, pitch, etc) since those can't be applied locally for the most part.

I also should have been clearer that Michael's specific point in his article was that if you take a plane with a close-set cap iron to a piece of straight-grained wood the forces will be higher. Obviously in that case you can just relax the cap iron set, as Kees pointed out, so it's a somewhat pointless debate.

I don't doubt that you use the cap iron more efficiently than I do. In particular I tend to be "binary" - either there's no tearout and it's set back ~15-20 mils from the edge, or I expect trouble and set it basically up as close as I can get it. I expect that with more experience I would be able to make more refined and continuous tradeoffs.

[Warren Mickley]

Warren, I wouldn't question your expertise, but doesn't this depend on extent? if you have a very localized grain reversal causing a narrow band of tearout, then in my experience the increase in cutting force is modest relative to the overall effort. In contrast you generally pay "full price" for mitigations (cap iron, pitch, etc) since those can't be applied locally for the most part.

I also should have been clearer that Michael's specific point in his article was that if you take a plane with a close-set cap iron to a piece of straight-grained wood the forces will be higher. Obviously in that case you can just relax the cap iron set, as Kees pointed out, so it's a somewhat pointless debate.

I don't doubt that you use the cap iron more efficiently than I do. In particular I tend to be "binary" - either there's no tearout and it's set back ~15-20 mils from the edge, or I expect trouble and set it basically up as close as I can get it. I expect that with more experience I would be able to make more refined and continuous tradeoffs.

Actually if there is one part of the board that is tearing out, it is that section which will tire a worker out, jarring his frame whenever it is worked. How easy the rest of the board is is not so important.

I searched the thread for references to Michael, but found none.

Your "binary" use of the double iron is a very clumsy approach. I have avoided providing distances for cap iron placement for nearly a decade because the cookbook approach is not so profitable in this work. The distance depends on the quality of the timber and the extra force needed is not so very apparent if the cap iron is well placed.

[Patrick Chase]

Actually if there is one part of the board that is tearing out, it is that section which will tire a worker out, jarring his frame whenever it is worked. How easy the rest of the board is is not so important.

To be clear I was referring to the case where tearout happens in narrow strips, such that most of the blade is cutting cleanly and only a small portion of it is seeing higher cutting forces due to tearout. The impact of tearout on overall cutting force is thereby diluted even within a single section. Admittedly that isn't terribly common - I've mostly seen it with species like Mahogany, and in some quartersawn pieces with nonuniformly interlocked grain.


I searched the thread for references to Michael, but found none

Whoops, that was an error on my part. I was referring to Stewie's quotation from Richard McGuire. My apologies.


Your "binary" use of the double iron is a very clumsy approach. I have avoided providing distances for cap iron placement for nearly a decade because the cookbook approach is not so profitable in this work. The distance depends on the quality of the timber and the extra force needed is not so very apparent if the cap iron is well placed.

Yes, that's why I highlighted it as an inefficiency in my current technique Thanks for the confirmation :-).

[Stewie Simpson]

the following article is a worthwhile read imo.

Stewie;


http://www.smallworkshop.co.uk/2016/02/14/bench-planes-the-cap-iron/
Once the plane blade starts to cut into the surface of the wood, the shaving rides up the blade and acts as a lever on the fibres ahead of it – the fulcrum being the leading edge of the mouth and the blade itself acting like a wedge. The leverage can cause other fibres that are connected to the shaving to be pulled from the wood before they are cut by the edge of the blade (“tear-out”).

One way to reduce the leverage exerted by the shaving is to adjust the frog so that there is a very small opening between the front of the mouth and the blade, thus effectively reducing the length of the unsupported shaving.

The other techniques involve causing the shaving to break early, for instance by raising the ‘angle of attack’ of the blade. That is to say, if you increase the pitch of the blade it causes the shaving to bend more sharply than would normally be the case, and this weakens the fibres immediately in front of the blade and, thus weakened, they are less likely to lever out fibres they are attached too.

One way to accomplish this is to use a modified frog that seats the blade at a higher angle than normal, and indeed so common was this technique in days gone by that the preferred angle (50°) was given its own name (“york pitch”) compared to the standard pitch (~45°).

The argument follows that the cap iron has the same effect, presenting a steep surface to the shaving and thus creating an effective higher angle of attack.

http://www.smallworkshop.co.uk/wp-content/uploads/2016/02/shavings.jpg

[Stanley Covington]

Here are some pictures of the end products of a natural stone.

I will include more pictures in subsequent posts to this thread. I think this is the best way to understand what Brian is trying to convey,

Stan

[Stanley Covington]

Here are some more pics that will perhaps help to illustrate Brian's point.

More pics coming.

Stan

[Stanley Covington]

Some more pics.

First is a shaving. This did not win any prizes, but it is decent.

The other pics are of something guys who are into sharpening over here work hard to accomplish once in a while. I have done it several times myself, and there is a knack to it besides simply knowing stones and steel. The blades are stuck to the stone's surface by water suction, and are not supported. The stones and blades are wet. As the water dries, the blade will drop free. Give it a try sometime.

Stan

[Stanley Covington]

Lastly, I am attaching pics of Japanese swords. I hope these will be informative about the historical background of sharpening in Japan.

There are some details you may find interesting, and that will help to dispel the confusion that always surrounds these beautiful blades.

First, unlike the planes and chisels and knives in my previous posts, the hamon (edge pattern) is not created by laminating the steel. While most Japanese sword blades are laminated with a softer mild-steel core to absorb shock and provide flexibility, the steel you see in the pictures on the sides of the blades is all continuous and homogeneous. The pattern is due to differential hardness, but more importantly, shows the varying crystalline structure at the surface of the steel (and which goes down inside the blade too, of course).

When a professional sharpener sharpens, or "polishes" a sword as the term is used nowadays, the beauty of the crystalline structure becomes vaguely apparent when he is done with the finishing stones, but it is his use of the thin slices of he various types of "uchigumori" stone that causes the patterns to jump out. Small slices of this stone are attached with lacquer glue to mullberry paper which he places under his thumb to polish the blade. A tremendous amount of skill and experience is required to do this work. Since ancient times, the sword polisher was higher in rank in Japanese society than the blacksmith that made the sword, frequently equal to the samurai, unlike the more lowly craftsman.

Many years have gone by since I had a sword polished. But back in the day, a top-quality polish by a top-tier polisher like Fujishiro san of a top-quality sword like a Sukezane or Nagamitsu cost as much as a new economy car.

Prior to the Meiji Restoration in Japan, the local lords of the samurai clans owned the mountains and mines where the highest-quality sharpening stones were produced, creating monopolies. The best stones were even more precious back then than they are nowadays.

It is not an exaggeration to say that sword blades were considered sacred then, and that they continue to have a deep hold on the DNA consciousness of the Japanese people even nowadays. Once again, this is not an exaggeration.

Considered in the light of cultural background, the Japanese obsession with sharpness and quality steel is understandable. It does not have its equal in the West. Natural sharpening stones are part of that heritage. A Japanese craftsman that believes himself good with planes and chisels and knives will always try to go beyond simple sharpness to achieve beauty in his blades. This is the rabbit hole of which one must beware. The tea party at the bottom of the hole is a lot of fun, if costly. Don't forget to bring a nice coat and hat.

Stan341235

[Brian Holcombe]

Awesome Stan! Those pics are really wonderful.

BTW, I am attending Kezurou Kai in Brooklyn, NY at the end of August. Should be fun.

The picture of those Nomi are really something incredible, that is the best looking ura I have seen on a chisel!

[Brian Holcombe]

I have some photos of my practice run on Honduran mahogany (I should really go out and buy some hinoki cypress to practice on....and later turn into furniture).

http://i27.photobucket.com/albums/c181/SpeedyGoomba/99C36705-C78C-4C81-B1B5-CE4346B8E1C0_zpslkv3cxs6.jpg

http://i27.photobucket.com/albums/c181/SpeedyGoomba/A87E6565-D97E-4A1F-935D-481EE101921B_zpsvrzz7qia.jpg

http://i27.photobucket.com/albums/c181/SpeedyGoomba/4FC39A1E-2CE7-4B60-BDB0-8626AA432846_zpsdg8cegnl.jpg

To stand a chance these shavings are going to need to get a lot thinner.

[Stanley Covington]

If thin shavings are the goal, Brian, then honduras mahogany will not do. Try Alaskan Cedar or Port Orford Cedar.

What woods are they using at the US Kezuroukai?

Stan

[Brian Holcombe]

I Definetly agree, it shines up nicely but thin shavings turn into fuzz. They are using alaskan yellow cedar, I need to hunt down some worthwhile softwoods for practice.

[Stanley Covington]

If you can get your hands on some clear, even grained white pine, it should work well too. Maybe easier to find than AC or POC. Maybe not....

[Brian Holcombe]

Thanks Stan, I'll keep an eye out for good white pine as well. Would western red cedar be worthwhile?

[Stanley Covington]

I've never used WRC.

Spruce would be another option.

Stan

[Derek Cohen]

Thanks Stan, I'll keep an eye out for good white pine as well. Would western red cedar be worthwhile?

I doubt it, Brian. WRC is rather coarse grained. Planing its end grain is a real challenge - crumbly in my experience.

Regards from Perth

Derek

[Brian Holcombe]

Ahh, thank you both. I've never used WRC even though it's fairly common here.

Stan, I might be able to get good spruce around here and I found someone who shows POC on their website.

BTW for giggles I measured that mahogany shaving...20 Micron! I stand a fighting chance if I can cut that down on better lumber.

[Luke Dupont]

Some more pics.

First is a shaving. This did not win any prizes, but it is decent.

The other pics are of something guys who are into sharpening over here work hard to accomplish once in a while. I have done it several times myself, and there is a knack to it besides simply knowing stones and steel. The blades are stuck to the stone's surface by water suction, and are not supported. The stones and blades are wet. As the water dries, the blade will drop free. Give it a try sometime.

Stan

That last picture leaves me terrified.

Absolutely beautiful tools in your previous post, though.