Pure Indulgence - Waiting for Customs

[David Weaver]

I'm pretty sure stanley would send me a poop in the mail if I did that, after going out of his way to hook me up with the chisel (he could've just kept everything the dealer had for himself).

(Plus, it's really thick, so I'd have to hit it with a really big hammer. )

[Stanley Covington]

The beta-ura Sam described is indeed bad news, but it is the eventual fate of a chisel sharpened many many times. It is something to embarrassed about only if the hollow is ground out while the chisel is still long. Unless the chisel is banana-shaped and grinding is unavoidable, or the blade suffers a deep chip resulting in the loss of the flat at the cutting edge, a flat back or bet-ura is not usually a problem.

There is one cause of beta-ura that can be avoided in both plane blades and chisels. Some people sharpen the flat on a medium stone (1000 grit or so) everytime they sharpen the blade. This will wear the back out swiftly resulting in a beta-ura early. I am sure David knows this, but for those less experienced with Japanese chisels (or even Western chisels for that matter), remember that once the flat is tuned and polished on your finest sharpening stone, you should not need to put the flat on anything but your finest finishing stone until the flat needs serious attention such as a re-grind. If you have a good finishing stone, whether manmade or natural (minimum 10,000 grit), and follow this rule, a bet-ura should not be an issue for many years.

But sometimes the flat needs to be "tapped out." This is harder to do on a chisel than a plane blade for a couple of reasons. First, the mild-steel used for chisels is usually harder than than that used for plane blades for structural reasons. Second, on a good chisel, the hard-carbon layer wraps around and up the sides of the chisel. This can be seen as a shallow "U" shape on the cutting edge. Plane blades are different with the high-carbon layer being more-or-less flat without the wrap. If you properly support he edge of a chisel or plane blade on an anvil of some sort, and carefully tap the softer jigane steel with a hammer, the softer steel will expand gradually bending the hard-carbon steel down towards the hollow. Normally, the same piece of high-carbon steel would crack if subjected to these sorts of stresses by itself, but with the supporting softer layer, it works. This bending is not accomplished by force, however, but by many tiny deformations. In the case of a chisel, it is possible in this way to bend down the center of the cutting edge, but not the edges where the high-carbon steel layers wraps up the sides. That means that it is dangerous to attempt to tap out narrow chisels. Therefore, with narrow chisels, the only real choice to correct a banana-shaped blade or the loss of a flat at the cutting edge is do grind the hollow.

At only 6 bu, I think that it would be risky to try to tap out the flat on David`s chisel if it had a problem. But if I recall, the flat was in fairly good shape and should not need such drastic measures.

Stan

[David Weaver]

It needed no more than 2 or 3 minutes on the initial diamond stone (which cuts the steel, but really isn't that fast now that it's broken in). It was a very low effort setup for a chisel, with predictable results in terms of sharpness.

I certainly would never touch that chisel's bevel with a hammer. Maybe on a very wide chisel, but someone like me and most of us working on tools and furniture sized stuff won't use those big chisels enough to get back to the ura, anyway.

As you say, I never touch the back side of a chisel with anything other than a finish stone after it is initially set up, and the blurb about wanting to preserve the ura as evidence that it wasn't overworked initially is, I guess, essentially about preservation.

[Stanley Covington]

It needed no more than 2 or 3 minutes on the initial diamond stone (which cuts the steel, but really isn't that fast now that it's broken in). It was a very low effort setup for a chisel, with predictable results in terms of sharpness.

I certainly would never touch that chisel's bevel with a hammer. Maybe on a very wide chisel, but someone like me and most of us working on tools and furniture sized stuff won't use those big chisels enough to get back to the ura, anyway.

As you say, I never touch the back side of a chisel with anything other than a finish stone after it is initially set up, and the blurb about wanting to preserve the ura as evidence that it wasn't overworked initially is, I guess, essentially about preservation.

You continue to impress me David. I'm glad that chisel found a good home.

I used mine over the weekend to chop waste in some 2-1/2" mahogany and it performed perfectly. The real test will be cutting deep mortises in silica crystal-infested tropical hardwoods, but after this initial test, I have no doubts it will perform beautifully.

By contrast, the widest of the Kiyohisa brand (White 1 steel, made in Sanjo) butt chisels I bought a couple of years as a temporary replacement for my Kiyotada butt chisels did not perform nearly as well in the same mahogany. They are just too damned soft, and I am very disappointed in them. It is getting harder and harder to find really good Japanese tools nowadays. So sad. I may need to start having Konobu make chisels. He only works in Blue Paper Steel....

Stan

[Stanley Covington]

You continue to impress me David. I'm glad that chisel found a good home.

I used mine over the weekend to chop waste in some 2-1/2" mahogany and it performed perfectly. The real test will be cutting deep mortises in silica crystal-infested tropical hardwoods, but after this initial test, I have no doubts it will perform beautifully.

By contrast, the widest of the Kiyohisa brand (White 1 steel, made in Sanjo) butt chisels I bought a couple of years as a temporary replacement for my Kiyotada butt chisels did not perform nearly as well in the same mahogany. They are just too damned soft, and I am very disappointed in them. It is getting harder and harder to find really good Japanese tools nowadays. So sad. I may need to start having Konobu make chisels. He only works in Blue Paper Steel....

Stan

I found a webpage with info about Kiyohisa. His products were recommended to me as being about the best currently available in White steel. But at the time, I was warned that he was not up to Kiyotada's standards. When I later complained about them, I was told that he intentionally made his chisels on the soft side to forestall complaints from amateurs that did not know how to properly setup or maintain a chisel with a harder edge. Too soft.

Stan


http://www.japan-tool.com/nomi/Kiyoh..._Dovetail.html
http://www.japan-tool.com/nomi/Kiyoh...isa_Tsuki.html

P.S. I have never used Bachi chisels. Has anyone else?

[george wilson]

Note on the "tap tap tap" video mentioned earlier: I would never use a diamond stone to flatten a stone,then use the stone after the diamond was used on it WITHOUT wiping the stone very clean. I'd be too concerned about stray diamonds,much coarser than the fine stone,being left on the fine stone,to scratch up my surface. I also would not use a curved top railroad rail to flatten anything. Get a flat anvil surface! And,get one that is not full of big pits all over!!!

[Stanley Covington]

Note on the "tap tap tap" video mentioned earlier: I would never use a diamond stone to flatten a stone,then use the stone after the diamond was used on it WITHOUT wiping the stone very clean. I'd be too concerned about stray diamonds,much coarser than the fine stone,being left on the fine stone,to scratch up my surface. I also would not use a curved top railroad rail to flatten anything. Get a flat anvil surface! And,get one that is not full of big pits all over!!!

AMEN!!!

Stan

[Ron Kellison]

"The smith's name is Kosaburo Shimamura, and passed away some years ago. He worked with his son for many years, but his son was badly injured in a traffic accident and was unable to succeed his father."

I have two long-handled paring chisels purchased during a visit to Kyoto that are labeled Kosaburo. The handles are round and slightly canted. They take and hold a wonderful edge!