Monday, June 4, 2012

Japanese Chisels - Tapping Out

I took a break today from the Japanese box to shower some TLC on my Japanese chisels. Three of the larger ones had never had their backs flattened properly. Mainly because it was way too tedious, but also because I rarely use the larger sizes.

After some token flattening on my new coarse diamond stone, I realized that the leading edge of the bottom on these chisels was curved up to such an extent that what was needed was to tap the front of the chisels with a hammer. I gather this is a fairly common set up activity among Japanese chisel owners.

I won't get into the details of the operation, a google search will yield plenty of information. My own observations are that is should be called 'bashing out' rather than tapping out as it takes way more force to get the steel to move than tapping would provide. I wound up using a carpenter's hammer on a piece of railway track to get one to move! Further, a caution that the leading edge will chip if you are careless and hit it directly.

Anyways, now my Japanese chisels are all flat and sharp and ready to go! That only took all day.

4 comments:

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  2. Dan,

    interesting post, however it is not the case that tapping out, ura-dashi, "is a fairly common set up activity among Japanese chisel owners". I've NEVER tapped out a chisel and I've been at this a while. Only plane blades need tapping out as they must maintain their shape to fit properly into the dai. Chisels have no such limitation, and all one needs to do is flatten the back on a stone. No tapping out is required unless some aesthetic concern for maintaining the shape of the hollow in a certain way impels one to do so. When the hollow is reached by repeated sharpenings, simply re-flatten the back, focusing on just the last centimeter or so of steel, feathering it in to re-establish the lead edge of the hollow. Not a tedious activity at all, given that the hollow removes 90% of the cutting steel from any involvement the process.

    That your chisel was curved up to such an extent - by no means is this 'normal'. That's a defective chisel and was not well-forged. You would have been better to return it. Let me guess: did you get it from Japan woodworker?

    Keep up the good work on your toolbox. And how is it that POC logs are washing up on a Vancouver beach?!

    ~C

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  3. Chris,

    Thank you for the correction there, I was mistaking what is done on plane blades for chisels. And you are right, I DID get them at Japan Woodworker. Guess that's a lesson for the future for me. (Kind of like buying from Jess-em?!)

    The Port Orford are street trees that get cut down by the city and dumped in a log dump on the beach. They do not grow natively here as you would know!

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  4. Dan,

    I will say this for Jessem: they are dedicated to improving their product and are responsive to customers. I cannot say the same for the JW store.

    I lived on Gabriola for a few years and all sorts of treasures washed up on the beaches there, so I share your excitement for the hunt in that regard.

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