First set of Japanese Chisels – Paring Type – Sharpening tips please
I have received my first set of Japanese chisels. These happen to be paring chisels. I noticed they all have a shallow arc to their necks and upper portion of the blade decreasing as it end at the bevel end. The arcs are all the same, so my assumption is that was done intentionally by the maker. I am curious if there are specific methods of sharpening this type of chisel (paring) with this arc. Since I need to set these up per the article in the archive, none of the articles I have found yet seem to address this arc in the chisels or if a different techniques is best to be using, specific to this different body style. I have 2 different sharpening jigs, but as western chisels (even the paring type) do not have this shallow arc, is there some other technique that is supposed to be used? I guess I could muddle through free-handing it, but am hesitant as that may make a mash-up out of my brand new chisels. Any and all tips/tricks/hints are most welcome.
Thank you in advance.
Daniel
Replies
Picture, or link?
I'm not sure if you are describing the depression on the back of the chisel, and if you are its purpose reduces the need to flatten the whole back.
My go to source for Japanese tools, maintenance, and sharpening is Wilbur Pan
I am referring to the neck/blade not the hollow in the back of the blade. I bought these from Woodpeckers: https://www.woodpeck.com/kinari-nomi-paring-chisel-6p-set.html
If you are talking about the arc that forms from the blade extending out to the handle as shown in the attached image. Then short answer is ignore it as it has no impact on the sharpening of the tool. The blade should sit flat along its length only at the neck of the chisel should it crank up, lifting the handle. This is done so to afford you the ability to pare without the handle obstructing your access to the work.
Now on some chisels the arc starts a little earlier and the blade does have tiny subtle bend to it along its length (thinner/narrower blades seems more prone to this), however this is not a concern because only the leading 25mm (1") of the blade needs to be reference flat. As these chisels are so thin that you push out any bend during use.
I use a LN honing guide. Standard water stones. Protect the hollow at all cost, the hollow can be easily erased. When lapping the back be conservative, try to do the least amount of work with coarse stones, and more work with finer stones this makes more work for you but it slows you down and protects the hollow (Ura). Remember you are only looking to really flatten then hone the first 25mm (1") not the whole length of the back.
Enjoy the adventure.
These would work just fine in a Lie Nielsen honing guide. I'm pretty sure they would work in others, too, but can't say for sure.
There is no standard certainty that the entire back (covering the whole ura area) should be dead flat. Some chisels are forged with a gradual convexity on the back and some are flat with the tang cranked to achieve something similar (not all will completely clear a flat surface, either - I doubt they use their parers the way we consider patternmaker chisels to be used).
If the back of the chisel has a gradual convexity, you prepare only the fat end (not half of the chisel back, either, as you'll cut through the thin lands at the sides in the middle of the ura quickly). Just hone the last quarter or half an inch. Honing the entire ura isn't ever necessary, nor is it a particularly good idea as they may not all be perfect - just the end.
If you try to hone a chisel with gradual convexity into a flat back from end to end, you'll wear huge amounts of the chisel away and have a mess.
The rule in general for all tools is you accommodate their biases. If there is a gradual smooth convexity across all chisels, it's made to give you relief when working (this is better than a dead flat chisel for an advanced user). Go with it rather than fighting it. The idea that chisels now are in some kind of geometric plane within a few thousandths is sort of dopey because chisels never go into a cut flat. They come out of it or they dive. If you have some convexity on the back, you have a little bit of relief to fight the diving in a heavy cut.
After rereading your question, I'm less sure if you mean the bevel or the back of the chisel.
The bevel on a lot of these chisels is a little bit convex because they're finished on a wet wheel and relatively quickly. Wet wheels are round. A dead flat bevel on the front of a chisel isn't really going to happen - it's up to you what you do with it.
I've gotten several hundred used chisels from japan - some have clearly been in recent professional use and many haven't. It's exceedingly rare to see a japanese chisel in professional use with a perfectly flat bevel. They're usually slightly convex because such a shape is far more natural to create.
The backs (with the ura) are all across the board, from being totally flat all the way to the tang shank of the chisel up toward the tang to convex for some relief in the cut. There is no correlation between any of these shapes and the price.
Princely sum for that set of chisels from woodpeckers, but I guess that's the nature of buying japanese stuff in the US.
This forum post is now archived. Commenting has been disabled