Sharpening Japanese Chisels; did I screw up?

[David Wong]

Luke,
Is it possible the previous owner applied some variation of the "ruler trick", to put a back bevel on your chisels? Seem odd that they have a consistent 1/2" length of back bevel. Perhaps it is a manufacturing defect.

I have had a few Japanese chisels from different makers that had slight to significant convexity on the backs. Initially, I wanted to preserve the aesthetics of the chisel back, so I choose to flatten just the portion of back in front of the cutting edge, leaving some belly on the chisel. After using the chisels, if the belly caused me problems, I would flatten the entire back. For flattening, I would use some combination of sandpaper on a surface plate, silicon carbide grit on a kanaban, and 220 water stones.

Flattening a chisel with a belly will reduce the hollow, but the hollow is serving one of its purpose reducing the effort to flatten the back. Nothing to be embarrassed about.

[Gary Howorka]

Know this is an old thread but thought this might be of interest to you.

https://www.youtube.com/watch?v=yRLyLZHR7ME

apparently this is common with Japanese chisels. This guy shows how to light tap the front until your back is all in the same plane. There is a second video on sharpening the bevels.

Gary

I ordered an inexpensive set of Japanese chisels to give a try, just to see if I liked them. These, specifically: http://www.amazon.com/dp/B004GBKYN2/...apanese+chisel

I got them, and after setting the hoops, went to sharpening, and I noticed that it was extremely difficult to lap the back. I started with the 1" chisel, and I couldn't get the last half inch towards the cutting edge in line with the rest of the back. I think I got it down to about 3/16" from the edge, after more than an hour of work on my diamond stone.

Then I realized, looking at the other chisels, that they too have the first 1/2" or so on a different plane from the rest of the back. This makes me wonder; am I supposed to leave them this way, and not lap them dead flat as one would do with western chisels? What, then, is the purpose of the hollow found in Japanese chisels?

Also, what should I do with my chisel that I've half-lapped? It nolonger has a large enough reference surface to sharpen only the tip with, but it also is still quite out from dead flat, meaning I can't just place it flat on the stone to sharpen with -- so, I effectively have the worst of both worlds. I am starting to wear away the hollow in the middle, which I know is not ideal. Should I try to re-establish that secondary flat which was originally there, or just commit to a dead flat back and spend a few more hours grinding?

Also, uh, is it some terrible, taboo practice to sharpen Japanese chisels with a convex bevel? This is how I sharpen my western chisels and planes, and what I've done already on my 1" chisel; I tend to prefer this method, and the resulting geometry. However, I've noticed that most Japanese craftsmen seem to keep a flat bevel and use that as a guide when sharpening, which is why I ask.

This is why I didn't buy expensive Japanese chisels right off the bat

[Stewie Simpson]

It was interesting listening to the advice given within the video, and comparing that to the advice posted by members of the forum.

Stewie;

[Brian Holcombe]

Phil Fuentes is a very talented knife maker and Japanese tool user. I've never used that technique of burnishing on a flat plate, since I generally just use a fine stone when tapping out, but it is a really neat idea.

[peter Joseph]

I'm surprised no one else suggested that you send them back. If you want to try japanese chisels on the cheap, look at Grizzly's offerings. I was given a gift card probably a decade ago and decided to order a set of 10. I still use them nowdays (albeit very infrequently) but they remain very sharp between sharpenings and came to me almost dead flat.

[Bill White]

I still adhere to the principle of "how much is enough". Do the chisels cut wood?
Not being a nay-sayer at all, but how scientific do we REALLY need to be when using our tooling?
Luke, if the chisels work........put 'em to work.
There. I've opened a REAL can of worms, but then I have hold fasts made by blacksmiths, planes from Stanley, chisels from Butcher, and (GASP) a Grizzly table saw.
Press on regardless.
Bill

[Brian Holcombe]

There is a reason why Japanese chisels should be setup correctly, and the reason is that it makes further maintenance very easy. Put the work in upfront or later on down the line, whichever you prefer.

[Stanley Covington]

Know this is an old thread but thought this might be of interest to you.

https://www.youtube.com/watch?v=yRLyLZHR7ME

apparently this is common with Japanese chisels. This guy shows how to light tap the front until your back is all in the same plane. There is a second video on sharpening the bevels.

Gary

Tapping out the back of chisels is seldom necessary, but occasionally is useful the first time one sets up a new chisel or badly abused one. It won't work on narrow chisels, however, so don't expect it to fix all your problems.

The video was very abbreviated, and Mr. Fuentes was never given time to perform any of the steps to completion.

The steel plate or kanaban he used is the traditional tool. The video did not show him using the silica carbide powder normally applied for serious work. And of course, he did not talk about the pitfalls of the kanaban. I think a diamond plate is safer for most folks, if more expensive.

During the next video on sharpening the bevel, once again, he was never given time to complete any step but was rushed on to the next quickly. Too bad. Consequently, the bevel was hideous and nowhere near sharp.

I wasn't impressed with his technique on the stones, although it was typical for most guys with a moderate experience. Take shorter strokes, use the entire surface of the stone including the edges, use the mud more effectively, and not skew the blade so much.

2 cents

[Stewie Simpson]

Mr Fuetes offered Luke a traditional Japanese method to resolve the issues with the backs of his Kakuri Chisels. Kudos to Gary Howorka for posting that video.

Stewie;

[Stanley Covington]

My main point was that Mr Fuentes was unfortunately not provided enough time by the presenter to give a thorough demonstration.

Mr Fuentes's sharpening technique, at least what we saw in the video, was entirely adequate, but I pointed out some ways he could have used the stones more efficiently. Just my opinion, of course.

[Prashun Patel]

Stan and Stewie: Tried to keep the essence of the debate but remove the more ripe top notes.

I have gotten a number of PM's advising that my editing is heavy handed. I apologize and really respect all of your contributions. I'm humble with respect to the content. So, please realize that I don't take editing lightly.

I am attempting, though to preserve an atmosphere where posters can challenge each other without getting personal. The personal attacks are regrettably often interwoven with relevant thoughts on the topic. I edit to avoid throwing babies out with the bathwater. When I feel my editing is controversial, I send the poster a PM. But sometimes, I just have to break up a fight. There isn't enough time to edit and also send PM's in this case.

I always remain open to restoring certain posts if you think you or someone in particular has been wronged. But I urge you to give me specific instances to correct.