Sharpening Japanese chisels - the irritating part

Re: Not the theory

Denis Ch�nard, Orl�ans, Ont.

>What magnification did you use with the microscope?

DC

Re: Enough said?

thomd

>"Marks may be a saavy worker, but I wouldn't be comfortable with someone whose advice is to hollow grind Japanese chisels and top out at 6000 on a man made water stone (natural stones aren't graded that way). The problem for people who bravely put themselves out there as experts/teachers is that often they are of only midlevel, or even beginner, experience in some areas; but we, the watchers, are sitting there thinking they know it all. That's not fair to anyone, and meanwhile, lots of bad/not-the-best advice is propagated, without the intent of the teacher."

Also, think of one's own journey over the last X years. I sure don't want to be held to something I said last year or 25 years ago. Also, all teaching is aimed at some level of student. I used to wonder when I did my seminars whether anyone actually got anyting out of it. i tried to teach to the level I thought the students needed based on what they would say in answer to early questions, but even then I think a lot of them are as much put off by courses as encouraged by them. The exception is the course where you build something as part of the course, though even then many people lack the confidence to repete what they have done in the course and the jump start effect wears off.

I agree that's a terrible way to sharpen a Japanese chisel or at the very elast it is hard to see why a Japanese chisel would be needed in that environment.

Whenever I get to one of the BS questions I aways try to relate it back to soemthign I care passionately about. Ok maybe this business about art level chisels and stones is a little hard to beleive for soem. But isn't there anything we can compare it to in woodworking? What about if you made the perfect ladderback chair, and you give it to someone. You come back and find they installed casters on the legs, painted it, and ripped out the bark seating for a foam and naugahide cushion. Those are all higher tech probably more convenient things. But it would be nice if the person respected the ladderback chair enough to hold off on the renovations until they figured out the chair's particular music.

Not really

jim reed @ tallahassee

>*the main purpose of hollow grinding is to accelerate tool wear*. I don't agree. Except for the exact cutting edge, all hollow grinding is done on the relief side of the blade. What happens to that metal is of very little concern in the overall picture.

Re: Not really

thomd

>I don't agree it's of little concern that there is a hollow. It may not be of concern in specific case. However it's a whole other story.

On the accelerating wear thing I think it's the purpose and the result. In practical terms the way the grinding proceeds is that one cuts until there is a burr from a 60 grit wheel or thereabouts, this usually produces quite a significant loss in chisel length. That's what I would call the result. But surely that's what we want, for the sharpening to be fast and effective. It's a very good way to proceed with a HSS cutter for a machine tool where the blank is perhaps 2-6 bucks. We are working a material in the case of Japanese chisels that is somewhere in the range of silver-gold by weight.

The secondary objective is often getting the hollow grind so it is easier to read the subsequent hand sharpening, and faster to sharpen. Cutting rate is relative to the PSI on the surface, and the steel cuts faster by hand when there are only two lines worth of to remove. That's the stated objective, faster sharpening. And again it means increased wear.

If you are suggesting the purpose to grinding is to remove less material than on finishing stones, that's quite a sales pitch.

I disagree

Paul in NJ

>"In practical terms the way the grinding proceeds is that one cuts until there is a burr from a 60 grit wheel or thereabouts"

Maybe that is the way you grind, but not me! I never grind to a burr, that is a good way to overheat your steel. I leave a little bit of the edge, maybe a 1/64-1/32. The object is to remove most of the steel with the grinder and not your honing stones. When I hone, I only hone until the edge is sharp, I don't remove any more of the edge than you. Like you said, it is faster.

Paul Dzioba

Re: Not really

Paul Kierstead

>In practical terms the way the grinding proceeds is that one cuts until there is a burr from a 60 grit wheel or thereabouts, this usually produces quite a significant loss in chisel length.

I think you need to define "significant". I'll give you that the first time it is done, there is some loss. In subsequent grindings, assuming a repeatable jigged set-up or very skilled hand-grinding (such that the angle is not altered), I can see no reason why more then a very very small amount of steel would need to be removed, nor why it would be more then other methods.

We are working a material in the case of Japanese chisels that is somewhere in the range of silver-gold by weight.

Although I am inclined to agree with you, I also think that when the value of the tool is part of the consideration, you have a tool which -- for you -- should be on the shelf and not in your hands. It has become a "collector", not a "user". That is why I don't own any chisels costing $100/pc. It seems to me that one is missing the point of a 'tool' if cost is a consideration in normal use. (And I am not referring to using a chisel to open paint either .. normal is keyword here).

Re: Sharpening Japanese chisels - the irritating p

Pam Niedermayer - Austin, TX

>Maybe you should somehow rig up a stationary bike so you could ride while sharpening. :)

Pam

Re: Abusing furniture

Pam Niedermayer - Austin, TX

>But it would be nice if the person respected the ladderback chair enough to hold off on the renovations until they figured out the chair's particular music.

Or until I was dead. :)

Pam

I tell you this: Nobody knows it all, NOBODY!

HC Sakman

>

Re: Country boy sez...

thomd

>Sandpaper is good stuff. What I take from this is that one can try and find better matches with a variety abrassive products.

Re: Comments and observations

Dave Burnard

>I think a lot of what goes into finding a good natural stone applies just as well to manmade stones. They clearly aren't all the same, they differ significantly from manufacturer to manufacturer. Shapton has gone through about 5 iterations in the last few years - and now I find I actually prefer the older wood mounted Shaptons to the newer professional series stones.

It doesn't matter to me which mine/layer my stones came from any more than it matters which manufacturer/series a manmade stone came from. What matters is whether I can efficiently produce a wicked sharp edge. So whether you use natural or manmade stones - I would suggest you look around a bit, swap stones with your buddies if you have to, but try out a few different stones and see what works best for you. The difference between a nice stone and an average one can make a big difference in your sharpening results, speed and enjoyment.

After all if we don't enjoy sharpening, then it's much harder to enjoy our neander playtime. ;)

Re: Matte vs. Mirror Finish

thomd

>We had a guy at seminar who not only believed the natural stone are better, but that he had reached a point of development with his chisels that just sharpening them on the artificial stones would be a serious set-back. It wouldn't be just a step down from his usual level, but as though he would have to start all over again. I found that part hard to believe, but i don't think he is alone in beleiving it. Seasoning or something.

It is a relatively comon phenomenon that scientific types, will dismiss an ancient belief, only to later find there was a reason for it. Normally the scientifc position in such circumstances is to call the thing they don't understand a superstition, or religious observance.

I like your way of thinking

Denis Ch�nard, Orl�ans, Ont.

>However, sharpening/honing tools don't rank high in my pleasure list :-)

I want to get the best edge possible, and get there fast. That's why I'm training myself to do everything freehand, it is a pain in the short term, but I'm getting better at it, and it's so much faster...

Does it show that I have three young kids (youngest just turned 1) and little shop time? :-)

DC

Re: Comments and observations

Pam Niedermayer - Austin, TX

>What Dave said, a very wise approach.

And I don't buy that the absolute edge comes from natural stones. 200 years ago that was probably the case, but I can't believe that one can't get better results with the array of man-made abrasives available to us today. Where the hype kicks in is when someone claims that this natural stone gives the best edge, and we're supposed to take him/her at their word. Feels too much like an infomercial to me... Nowhere is there demonstrated evidence that this is the case. I'd like to see a Steve Elliott type of study on natural vs. man-made stones vs. other methods (paper, diamond, etc.). Frank's results are somewhat baffling, this should be investigated further.

While I agree that testing this would be a wonderful project for someone else to do (I tend to not be a quan type), I find the rest of this paragraph a very interesting statement, particularly as it's so easily counter argued based simply on how our planet has been "improved" in the 600 years or so we've been able to even think about such things. Here we have a perfectly good rock making it's way toward entropy without our help for billions of years all of a sudden, after our help, change direction and head toward chaos. We are indeed omnipotent and omniscient.

Pam

Re: Paring chisels for best edge

Dave Burnard

>I've gotten a few unusual things from Nakaoka-san as well. He is really putting a lot of effort into his website, webstore and info pages. In sword polishing I know that chu nagura precedes (is coarser than) koma nagura - and most koma nagura are white or striped like the naguras we usually see for woodwork sharpening. Circumstantial evidence though.

The really hard stones I have are very difficult to heep the bevel in contact with the stone without it "chirping" across the stone. They don't build up any paste on their own and require frequent use of nagura to cut effectively. Still they have their uses... They are also very pretty to look at which was one of the reasons I picked them - despite their hardness.

Your question about tools from the same blacksmith sharpening the same, would assume that the tools are all made out of the same iron and steel, hardened the same, had the same bevel angle, etc. I'm thinking that's what you meant, that things made from similar materials in similar geometries ought to sharpen the same. So all of the chisels in say a blue steel bench chisel set ought to be essentially the same (I haven't come across outliers in my sets) - but a fancy paring chisel from the same maker but made from watetsu and pre WWI white steel would feel different on the same stones.

Re: Not the theory

Frank D. in Montreal

>Hi Denis,

I asked Claude on lamortaise.com. I bumped up the original thread so you can read it (unfortunately the pics are missing since the original gallery was hacked and destroyed).

Waxing philosophical, Pam?

Denis Ch�nard, Orl�ans, Ont.

>"While I agree that testing this would be a wonderful project for someone else to do (I tend to not be a quan type), I find the rest of this paragraph a very interesting statement, particularly as it's so easily counter argued based simply on how our planet has been "improved" in the 600 years or so we've been able to even think about such things. Here we have a perfectly good rock making it's way toward entropy without our help for billions of years all of a sudden, after our help, change direction and head toward chaos. We are indeed omnipotent and omniscient."

I can't argue with this, however I fail to see the link with man-made abrasives. What we've done to our planet is another thing. Anything else I might add could be construed as being political, so I'll stop here...

But if you want to keep this discussion going off-line, I'm game...

DC

Re: Not the theory

Denis Ch�nard, Orl�ans, Ont.

>Thanks Frank, I'll check it out!

DC

Re: Matte vs. Mirror Finish

Dave Burnard

>So he used natural coarse (700-1200grit) stones too? Wow, I'm impressed. I have several of the varieties of natural coarse stones and while they do work, the King, Bester, AquaStone, Shapton, etc. people did the rest of us a huge favor in my opinion. ;)

Re: Matte vs. Mirror Finish

Denis Ch�nard, Orl�ans, Ont.

>"It is a relatively comon phenomenon that scientific types, will dismiss an ancient belief, only to later find there was a reason for it. Normally the scientifc position in such circumstances is to call the thing they don't understand a superstition, or religious observance. "

Very possible, but I would choose "unproven hypothesis" instead of superstition or religious observance.

The thing is, no one seems to question the presenter, all is anecdotal evidence. That's not the way science works.

If natural stones are better, and they produce a better edge while leaving the bevel "frosty", then there should be a scientific explanation as to why this is the case. Anything less doesn't cut the mustard IMHO.

DC

Hey my chisel smells like Crest!

Dave Burnard

>Remind me to stop loaning tools to neighbor mikew, I thought that mokume paring chisel smelled like Crest when he returned it... Wouldn't cut worth a dang, but smelled minty fresh!

;)

Re: Hey my chisel smells like Crest!

mikew

>Hah. Never thought I would be found out. Better use the original Tom's of Maine next time!

Actually, the stuff is persistent and pretty abrasive. And it was Crest...hones the heck out of carving tools. Smells better than stones and MS.

And besides, if you hone just before bedtime, you can reuse the past .

Take care, neighbor.

Mike

Re: Matte vs. Mirror Finish

Dave Burnard

>It goes both ways. If man-made abrasives are better, and they produce a better edge while leaving the bevel "shiny", then there should be a scientific explanation as to why this is the case. Anything less doesn't cut the mustard IMHO. (That physics Ph.D. makes me cranky sometimes.)

In our world of mass production it's certainly cheaper and easier to manufacture a sharpening stone than it is to find and cut a nice one from a mine. The woodworkers of today will be the last generation to have access to the amazing variety of natural japanese waterstones. The mines are all closed now.

Re: Matte vs. Mirror Finish

Denis Ch�nard, Orl�ans, Ont.

>"It goes both ways. If man-made abrasives are better, and they produce a better edge while leaving the bevel "shiny", then there should be a scientific explanation as to why this is the case. Anything less doesn't cut the mustard IMHO. (That physics Ph.D. makes me cranky sometimes.)"

Granted. The hypothesis here that man-made abrasives used in the stones are of uniform (or close to) size, thus they abrade the steel in a consistent manner. Go fine enough, and the surface becomes so flat as to reflect light. If the back and bevel can become that flat, then their junction should be as sharp as possible.

OTOH, the more dispersed particulate size of a natural stone creates a random scratch pattern, which disperses light because of the less flat surface. Again these scratches on both bevel and back, when they meet at the edge, should make for a less sharp edge. Frank says that his observations contradict this.

The only way that I could explain this paradox it that the bevel and back, in contact with the stone, do indeed produce a rougher surface. But the slurry, being made of broken down particles, becomes finer and finer as we go, and it would be the slurry that does refine the edge. The bevel (or back), being in contact with new particles from the stone, can't get shiny because it's in contact with fresh particles of "random" size.

Does that make kind of sense?

DC

No Ph.D (dropped out at the thesis stage), but I did start in physics in university (long story).

Or waning.

Pam Niedermayer - Austin, TX

>It's only political if we make it so. I don't know of any rational person who's not running for office or running an oil company or who's living is otherwise dependent on keeping on keeping on (see, here I really wanted to say "staying the course" but denied myself in an effort to avoid any hint of politics :) ) who thinks we've not done serious harm to the planet, and, therefore, ultimately ourselves. Oh, well, maybe we'll start swarming into space real soon now, find us a new home planet or two.

Pam