Can you help me fix my first japanese chisel?

[Luke Castillo]

Hi there, first message in the forum and I was hoping some of the resident experts could help. I got an old nomi out of ebay, it looked ok and I paid very little, I received it today and I found a small issue, the previous owner put a micro bevel on the ura side that goes almost into the hollow, if you check the pictures below, you'll see how the light reflects on the micro bevel.

I have experience sharpening single bevel japanese knives and I have a good collection of waterstones up to 10k, plus pastes, leather etc, but I'm not sure what to do here, do I grind the face side a couple of mm until the bevel on the ura side is gone? If I do that, the face side will go into the hollow of the ura side, how do I restore the ura? Just grind it until I have a flat plane?

thank you so much for the help

http://i.imgur.com/OhLDigyl.jpg
http://i.imgur.com/H2KaLsZl.jpg
http://i.imgur.com/F5SDNvQl.jpg

[David Weaver]

Yes. Grind the face and focus your finger pressure on the middle of the edge so that you remove the metal exactly where you need less of the ura to be.

[Stanley Covington]

You need to remove the bevel on the ura side. I can't tell for certain from the picture, but if you think that will entirely remove the flat in front of the ura, I suggest you "tap out" the ura with a hammer and anvil and then flatten the back on a kanaban or diamond plate. If you have not done this delicate operation before, an inexpensive chisel like this is a great opportunity to practice. If you need some direction, and can't find anything on the web that seems useful, let me know and I will try to write up something tomorrow. It isn't difficult, but requires patience, deft hammer work, and an understanding of the principles involved.

Stan

[Wilbur Pan]

You have four options, as I see it:

1. Work on the back of the chisel until you get rid of the microbevel. This isn't going to be a lot of fun.

2. Grind away on the bevel side until you get rid of the microbevel, then work the back of the chisel until the flat reappears. This will be probably be less work than the first option.

3. If the chisel has a good edge, just use the chisel, and each time you sharpen, be sure to work the back a little. With time, the microbevel will go away, you won't lose the flat area between the edge and the hollow, and the process will be less annoying than in the first two.

4. Tap out, as Stanley mentioned. Here's a writeup on how to do it (http://giantcypress.net/post/5446904360/tap-tap-revenge). Here's a video showing how hard to tap (http://giantcypress.net/post/5634759952/given-that-tapping-out-a-japanese-plane-blade-is-a), which I found to be the majority of the learning curve, and hard to describe without seeing it, although I like to use the analogy of starting a finish nail in a piece of pine.

I would use option #3, unless the edge is crappy, in which case I would do #2.

[Derek Cohen]

I'd grind the bevel. Then lap the back of the blade until the hollow recedes a few mm behind the bevel.

If the steel appears to hard to do by hand, find someone who has a Tormek. This is safe. It creates a very shallow hollow and this will disappear quite quickly.

Regards from Perth

Derek

[Jim Koepke]

Having no knowledge or experience in this area, my only contribution is my inquisitiveness.

Can anyone explain what is taking place with the tapping out of the hollow?

Is the hard steel in the lamination actually deforming?

It seems counter intuitive to me that tapping the soft side of the lamination would then press out the hardened metal of the lamination on the other side.

jtk

[David Weaver]

Yes. As long as the forge weld is solid, it will continue to cling to the wrought that you're bending and it will actually move with the moving wrought iron. But the iron must be what is moved to influence the hardened layer vs. the converse.

[Jeff Duncan]

There's one last resort if your unable to remove that bevel.....you could use it for trimming edge banding;) I took an inexpensive chisel and put a small bevel on the back like that specifically for the purpose of trimming edge band without digging onto the panel. Works great as a little specialty tool! I'll leave the advice for fixing it up to the others though:)

good luck,
JeffD

[Luke Castillo]

Thank you all for your responses, I just put 1 hour and 20 min of sharpening/meditation, the stones invited to the party were a DMT XXC, Naniwa SS 220, Naniwa SS 1000, King 6000, Belgian coticule, and Naniwa SS 10k, the finishing compounds were black diamond on balsa, chromium oxide on balsa and raw leather, the album of choice, Led Zeppelin II.

The results were ok, not great, I got rid of the micro bevel but after grinding the ura for a while I still have very little meat behind the edge, another issue I found while sharpening is that the previous owner was extremely lazy and only sharpened the first 1/8 of the ura so I had to grind everything to be on the same plane, nevertheless, I managed to get it shaving sharp, I'll try this week the tapping out method, for science.

again, thank you very much for your help

the pics

http://i.imgur.com/WgvkdR0l.jpg

http://i.imgur.com/j0UOijGl.jpg

[David Weaver]

What you've found is the reason I mentioned finger pressure. Heavy finger pressure right at the bevel and there only, because that's where you want to remove material. You're not going to be happy with what you have in the m iddle of the edge there until you've gotten into the ura, but once you do, presuming the ura is shaped properly, you're going to see the polished back grow quickly there. You don't want to remove too much more metal at the back of the ura at this point, assuming you want to get the full lifetime out of this chisel.

Something like stuck-down norton 3x on the order of 100 grit might be a good place to go. It is extremely aggressive, even much more so than a double extra coarse diamond hone, probably because all of the grit is fresh and sharp and it is very dense compared to the variable surface on most diamonds hones, and compared even to something like an atoma where the diamonds are neatly arranged but fairly sparse.

[Chris Vandiver]

Having no knowledge or experience in this area, my only contribution is my inquisitiveness.

Can anyone explain what is taking place with the tapping out of the hollow?

Is the hard steel in the lamination actually deforming?




It seems counter intuitive to me that tapping the soft side of the lamination would then press out the hardened metal of the lamination on the other side.

jtk

It's called cold forging. As a general rule it is not commonly done on Japanese chisels(but some people do "tap out" chisels, especially the larger sizes) but it is a must for Japanese plane blades where too much grinding will change the shape(and dimension)of the blade, making for an improper fit into the plane body. By the way, tapping out can be done on vintage western laminated plane blades and chisels too. Of course, one needs to be set up with some sort of anvil(with a properly shaped edge), an appropriate hammer(not too light), some knowledge of the method and basic hammering skills.

[Charlie Stanford]

Thank you all for your responses, I just put 1 hour and 20 min of sharpening/meditation, the stones invited to the party were a DMT XXC, Naniwa SS 220, Naniwa SS 1000, King 6000, Belgian coticule, and Naniwa SS 10k, the finishing compounds were black diamond on balsa, chromium oxide on balsa and raw leather, the album of choice, Led Zeppelin II.

The results were ok, not great, I got rid of the micro bevel but after grinding the ura for a while I still have very little meat behind the edge, another issue I found while sharpening is that the previous owner was extremely lazy and only sharpened the first 1/8 of the ura so I had to grind everything to be on the same plane, nevertheless, I managed to get it shaving sharp, I'll try this week the tapping out method, for science.

again, thank you very much for your help

the pics

http://i.imgur.com/WgvkdR0l.jpg

http://i.imgur.com/j0UOijGl.jpg

You certainly can't be faulted for not bringing resources to bear.

[Luke Castillo]

Thanks David,

I went back to the stones and focused solely on the bevel, you were right about how sensitive this operation is, one the ura is flat, you have to be extremely focused in where to put pressure, also, since there is so little metal and it is so soft you can eat it quite quickly, anyway, I managed to get around a mm extra, new chisels don't seem to have much more than that, check the pic, so I'll try to get an extra mm tomorrow and call it a day.

http://i.imgur.com/gtLBhPJ.png

[Wilbur Pan]

Nice job. I'd stop right there.

[David Weaver]

Thanks David,

I went back to the stones and focused solely on the bevel, you were right about how sensitive this operation is, one the ura is flat, you have to be extremely focused in where to put pressure, also, since there is so little metal and it is so soft you can eat it quite quickly, anyway, I managed to get around a mm extra, new chisels don't seem to have much more than that, check the pic, so I'll try to get an extra mm tomorrow and call it a day.

http://i.imgur.com/gtLBhPJ.png


I have that exact chisel. Those are an anomaly for Iyoroi and the ura is very precise on them. You'd find on that iyoroi that it gets wider pretty quickly because it is fairly shallow. a millimeter is fine, though. With care of the chisel, that will last a long time. I have not had to do anything special to my iyoroi bench chisels (like the one above) - as in I've never run out of the ura with regular use.

[Jim Matthews]

Am I alone in thinking this sounds like a finnicky PITA?

[Wilbur Pan]

I think that tapping out is often made out to be more finicky than it really is. I think the hardest part of tapping out is learning to be patient with the process.

[Stanley Covington]

I'll try this week the tapping out method, for science.

Luke:

I can't tell from your pictures, but if you have an Ouchi chisel, it is probably well made and the high-carbon layer of steel is "wrapped" up the sides of the blade, unlike a Japanese plane blade where the high-carbon layer is oriented straight across. This "wrapping" obviously makes for a deeper cross section of hard steel at the sides of the blade stiffening it greatly. Any efforts to "tap-out" the sides will be wasted and may damage the blade. This means that you need to focus 2/3 of your hammer taps on the center, and distribute the rest on other areas of the face, while avoiding the sides entirely. EZ PZ.

The worst that can happen when you tap out a blade is to accidentally strike the high-carbon hard layer at the cutting edge with the hammer breaking out a pretty half-moon shaped chunk of steel. Yes, I have done this before. A useful trick is to place a piece of masking or duct tape across the blade's bevel from a point at about half the width of the bevel to the cutting edge. If you work the anvil, avoid striking the tape with you hammer, are patient, and don't get too aggressive with your taps, all will be well. BTW, the anvil can be almost anything. I have a metalworking vise with a corner I rounded over and smoothed which works very well. A sledge hammer or even a framing hammer (not waffle-face) held in a vise will work. A railroad spike with a rounded smoothed head driven into chopping block works well too. Just tape a bit of thin cardboard over the anvil to act as a cushion and to prevent slipping.

Japanese chisels can be a pain to set up, but once you have a good one (and there are lots of junk ones sold in the States) setup properly, and the blade in good shape, they are worth every bit of the trouble. I have heard plenty of Americans complain about them, but when I have examined the chisels they complained about, in all but a few cases it became obvious they did not know how to setup and sharpen them properly.

There are two exceptions I have seen. The first is the cheapo chisel intended specifically for export at rock bottom price, and manufactured for a wholesaler under a brand name that can't be traced back to the actual manufacturer who would never want his domestic Japanese customers to know he made such crap. Caveat Emptor. You always pay for what you get, and sometimes you get what you pay for. Brand names have value for a reason.

Another exception is the guy who uses a decent Japanese chisel for the wrong application. For instance, stripping concrete forms or notching studs for braces will cause the blade to chip because the edge is too brittle for cutting stones or nails. That said, there are Japanese chisels made from tougher alloys that can handle such tasks, but the cost is difficult to justify for a tool to be used so roughly. In fact, while I shudder to think of it, the chisels with disposable blades make sense for such applications.

Good luck.

[Derek Cohen]

The results were ok, not great, I got rid of the micro bevel but after grinding the ura for a while I still have very little meat behind the edge, another issue I found while sharpening is that the previous owner was extremely lazy and only sharpened the first 1/8 of the ura so I had to grind everything to be on the same plane, nevertheless, I managed to get it shaving sharp, I'll try this week the tapping out method, for science.

STOP! You are done. There is no more work to do!

If you wish, lap the back of the blade a little more, but if it is flat and intersects without a backbevel, then you have a working blade. Lapping the back will cause the hollow to recede further back. 1000 grit first ... not too much as the hollow is shallower than you realise. Take it up to the polish of your choice. Then you are really done preparing the chisel for work.

Regards from Perth

Derek

[Jim Matthews]

I know some of you big dogs love the Japanese chisels.

I never got used to the feel of the hoops on mine.
The care and feeding of these seems more hassle than my meager skills merit...

To each their own, I suppose.

[David Weaver]

Am I alone in thinking this sounds like a finnicky PITA?

Like most things on here, more is being made of the process than there really is. The spot at the edge needs to be ground down. You put your finger pressure there and lap it until it's accessible, that's it. Sometimes, we can't let a simple answer be simple here.

In terms of maintenance, and I'm sure Stan will probably agree, once you get a good japanese chisel dialed in, there is very little to do. Little sharpening, and the back gets polished only. Setup time on a decent japanese bench chisel is similar to a middle of the road western chisel. After that, the bigger contest seems to be keeping the rust off if they are in a damp area, because they are mild steel, iron or a hard wrought on top of carbon steel. But they are no more challenge there than any other O1 or vintage western chisel.

If you don't like the hoops, though, pretty much SOL! I hate to see japanese chisels rehandled with bulbous western style handles or vintage US style octagonal handles. The handles on the japanese chisels are extremely accomodating when you grasp them by the handle in use instead of a pencil grip, and most of the videos I've seen show that grip, as do most of the older euro and american pictures. The pencil grip seems to be a more recent thing, when used universally probably arriving out of lack of repetition and experience.

[Luke Castillo]

Thank you again for all the recommendations, I lapped the back a little bit more and gained another half a mm, David's recommendation of focusing pressure solely on the bevel when lapping the ura side has been absolutely essential, I consider the chisel done, all in all I've put around 2 hours.

I tried it briefly this morning and it seems to work fine, sharp and it didn't chip, the bevel face is at 30 degree, no micro bevel. We'll see about edge retention.

Stanley,
it is not an Ouchi but a SHIGETOMO, the kanji(?) is 重友

[Stanley Covington]

Like most things on here, more is being made of the process than there really is. The spot at the edge needs to be ground down. You put your finger pressure there and lap it until it's accessible, that's it. Sometimes, we can't let a simple answer be simple here.

In terms of maintenance, and I'm sure Stan will probably agree, once you get a good japanese chisel dialed in, there is very little to do. Little sharpening, and the back gets polished only. Setup time on a decent japanese bench chisel is similar to a middle of the road western chisel. After that, the bigger contest seems to be keeping the rust off if they are in a damp area, because they are mild steel, iron or a hard wrought on top of carbon steel. But they are no more challenge there than any other O1 or vintage western chisel.

If you don't like the hoops, though, pretty much SOL! I hate to see japanese chisels rehandled with bulbous western style handles or vintage US style octagonal handles. The handles on the japanese chisels are extremely accomodating when you grasp them by the handle in use instead of a pencil grip, and most of the videos I've seen show that grip, as do most of the older euro and american pictures. The pencil grip seems to be a more recent thing, when used universally probably arriving out of lack of repetition and experience.

I agree entirely, David. I must say I do hate to see the ura on a good chisel ground down to nothing when tapping out the flat is a quick and easy way to setup the blade once and for all.

Stan

[Stanley Covington]

Thank you again for all the recommendations, I lapped the back a little bit more and gained another half a mm, David's recommendation of focusing pressure solely on the bevel when lapping the ura side has been absolutely essential, I consider the chisel done, all in all I've put around 2 hours.

I tried it briefly this morning and it seems to work fine, sharp and it didn't chip, the bevel face is at 30 degree, no micro bevel. We'll see about edge retention.

Stanley,
it is not an Ouchi but a SHIGETOMO, the kanji(?) is 重友

I don't know the Shigetomo brand. There was a famous Tokyo plane blade blacksmith that used that brand, but the only reference I have been able to find for chisels on the internet is this auction link http://aucview.aucfan.com/yahoo/e115329553/

The instant sale price for this new 10 pc set is JPY12,000, which is very inexpensive, and does not seem to indicate a high-end product. Not sure its the same as yours.

Stan

[David Weaver]

I agree entirely, David. I must say I do hate to see the ura on a good chisel ground down to nothing when tapping out the flat is a quick and easy way to setup the blade once and for all.

Stan

Yeah, hopefully if the chisel is well made, not much of the ura everywhere else will be consumed when bringing the edge back flush with the lapping surface. I also don't like seeing a ura that looks like a tiny nostril left due especially to the desire to get a less than flat chisel flat over the entire back. Some of the older chisels I've seen look like the back has been lapped hard with a medium stone every time they're honed.

[Frank Drew]

The Japanese carpenters I worked with used a narrow steel plate nailed to piece of wood and an abrasive powder (corundum? carborundum?) to lap out the back of a chisel when/if it got into the hollow. They used a strip of wood, like a piece of lath, on the top of the chisel, in line with the tool, for extra pressure -- they'd hold one end of the lath and chisel handle together with one hand and the other end of the lath with their other hand where the lath stuck out past the chisel edge a few inches) as they vigorously lapped the back. When enough flat reappeared they'd polish the back up through several stones. I think they reserved tapping for plane blades but I can't precisely remember.

[Stanley Covington]

The Japanese carpenters I worked with used a narrow steel plate nailed to piece of wood and an abrasive powder (corundum? carborundum?) to lap out the back of a chisel when/if it got into the hollow. They used a strip of wood, like a piece of lath, on the top of the chisel, in line with the tool, for extra pressure -- they'd hold one end of the lath and chisel handle together with one hand and the other end of the lath with their other hand where the lath stuck out past the chisel edge a few inches) as they vigorously lapped the back. When enough flat reappeared they'd polish the back up through several stones. I think they reserved tapping for plane blades but I can't precisely remember.

Yep, that's the quick and dirty method, Drew. Severely reduces the effective life of the chisel.

Stan

[Frank Drew]

Yep, that's the quick and dirty method, Drew. Severely reduces the effective life of the chisel.

Stan

Covington,

These were highly-skilled professionals who took great pride in their workmanship and the condition of their tools; as noted above, losing the flat ahead of the hollow doesn't happen very quickly or very often in the life of a tool, so this method couldn't have been a common procedure, but perhaps getting back to work quickly (they did this for a living) took precedence over tool life.

Nevertheless, should I have the opportunity I'll pass along your disapproval of their methods.

[Stanley Covington]

Covington,

These were highly-skilled professionals who took great pride in their workmanship and the condition of their tools; as noted above, losing the flat ahead of the hollow doesn't happen very quickly or very often in the life of a tool, so this method couldn't have been a common procedure, but perhaps getting back to work quickly (they did this for a living) took precedence over tool life.

Nevertheless, should I have the opportunity I'll pass along your disapproval of their methods.

Mr. Drew:

Sorry for not using your name properly; No slight was intended. And I am sure you are right that they did not use this method frequently, or when they had more time. I doubt they will be interested in anyone's disapproval, much less my observations which were not disapproval of the method but regret for the effect on the tool, which this thread is focused on.

Thanks.

Stan