Friday, September 12, 2014

New old kanna, Ura-dashi with a heavy hand, and a gift for a friend

Sometimes my writing skills lead me to despair. I, too have to read this stuff, and so often I feel that I come across as an overly excited 10 year-old (not too far from the truth, I suppose), but what can you do? How do you add emphasis except using caps and exclamation points? Parenthetic thoughts and related diversions........... open ended comments......At least my plodding diction, repetitive verbosity, and closed-eye silent thinking doesn't translate into print.

I'm trying to improve my photos, too. Thank God.

September feels like new/old tool month. Despite already having more tools that I can use (Some I don't even know HOW to use!), the other day I got some more old kanna from Junji (eBay seller yusui). Two are nice ones, but the third needs work..... Not much, but it might be somewhat educational.

The big news that is restructuring our lives, is that my lovely and exceedingly brilliant wife (Renee Bellinger), has accepted a post-doctorate position in Hilo, Hawaii. What I REALLY want to be doing is forging tools, making knives, saya-nomi (chisels specifically shaped for making wooden sheaths) being particularly prominent in my thoughts. Instead, I need to concentrate on making our house less objectionable to it's future renters, so I need to alter my mind-space and address some long unfinished projects. At least it will involve working with wood. Soooooo much to do, poor me..... Moving to Hawaii!!

A jakuri-kanna (groove cutting plane) for plowing the narrowest of grooves. 2 mm width!

This one is a bit unusual. In addition to it being the narrowest that I've seen, the cutting iron has been sharpened at an unusual angle.

Is this angle just the result of inattentive sharpening, or is there a specific intent at work here?

I grab a scrap of wood, to use as a simple guide.

This plane is flush to the left hand side, but otherwise has no adjustable fence (as a jakuri-kanna normally does), so this seems like how things should work. 

The kanna works fine (it was very sharp, as received), and cuts a neat little groove, just a hair over 1/16" wide. 

With two knives shearing the cross grain fibers, the main blade only need to plow out the waste in between. These are some of my favorite planes.

What about the angled blade, though?

This guy can be used tilted, to cut VERY tiny female dovetail grooves. It certainly looks like this was the intention. There are two pieces of pine tracked onto the sole of the plane, acting to stop the cut at 3 mm deep. What was this plane used for? What did this carpenter specialize in?

65 mm width kanna.

It's a quality tool. The dai is decent. It has a very sturdy, copper plated (?!) osae-bo retaining pin.

Both the main blade, and the back blade are laminated (good!), but both bevels have seen some pretty severe attention (bad?). It has the ubiquitous paper shim.

So many of my kanna have paper shims, I'm almost beginning to prefer it that way. Paper makes a great shim, allowing for good blade support AND.....a good feel for adjustment. Grippy, without being too tight. A kanna that has a paper shim is not cause for concern. Not much, anyway.

Both blades are in need of ura-dashi, having been ground back, clear to the hollows.

Nice blades, though.

The edges of both blades have been ground back 2-3 mm. The face of the bevel has seen LOTS of action from the pointed end of a hammer.

Here is a closer look.

Each of these dimples (100's of 'em) was caused by hitting the bevel face with a hammer.

This type to be exact. A funate pattern genno.

Pro Shop Hokuto had lots of great hammers.

What we have here (probably) is a kanna blade that chipped out very badly. The edge has been ground back about 2 mm. The bevel has been hit repeatedly, as part of the normal ura-dashi process, leaving many small dimples on the bevel face. All that remains is to flatten the back of both blades, them match them to each other.


This is an extreme example of periodic kanna maintenance. If you REALLY use your kanna as a tool, you will eventually chip a blade. Hard knots, unseen gravel, hell..... Clumsy hands dropping a blade during sharpening have probably caused more chips than anything else combined. You grind back the edge until you are in clean metal. Use a dry wheel bench grinder, but don't overheat the blade. Grinders are great tools, just take your time.

Here is a great one that I would love.

A cool running dry wheel on one side, a flat lapping plate on the other side. Charged with green compound for buffing, this would be a very efficient system.

This type of thing is what pros use. They don't dink around with 10 different stones, diamond sprays, etc. A #1000 grit stone, then #5000-#6000 grit....done. Maybe start with a #220 if things are really bad. It is mostly us enthusiasts, that like to bury ourselves in minutia, that turn sharpening into such a difficult process. Ura-dashi is the same way.

I was reading the blog of a professional tool sharpener a while back, and he detailed the process of how he fits a brand new kanna. Often the new blades are warped, and need to be forcefully adjusted. First he grinds the edge back about 4 mm, until the once sharp blade is instead a blunt flat vertical of about 2-3 mm. This is to minimize the likelihood of cracks developing. He puts the blade onto a stump, then wails away, using a sledgehammer. After he gets the blade into the shape that he wants, THEN he does the finer ura-dashi.

You would think that this extreme abuse would cause a blade to shatter, but it doesn't (usually). One of the beauties of the laminated construction is that it is very durable. Don't try this with your A2-cryo-powder-metal-whatever blade.

Ura-dashi is a regular thing, and not that big of a deal. The worst thing that can happen is that you might end up with a blade that needs more attention. Like this one. Use your judgment, take some care, and things will probably be just fine.


When pressed into place, the main blade is over 1 cm from where it should be.

The edge of the back blade has been ground back too, either due to damage, or just to maintain proper proportions. I can't tell yet for certain.

This kanna needs the ura-dashi process finished. The main blade and the back blade need to be matched. The main blade is now too tight, so the blade bed needs to be adjusted. The sole of the dai is then given a final adjustment, and she should be ready to work. It's a lot of work, but then again, NEW Japanese tools often need all of this done, too. This kanna was $16, if memory serves.


A seme-ganna, bought as a present for a friend.

A seme-ganna/ seme kanna, whatever, is a very specific type of kanna.

The blade width is only about 24 mm or so. That's 1" for us metrically challenged.

The kanna sole is beveled to either side of the cutting edge. The bevel extends right to the corners of the blade.

The relieved sole allows you to get right into the inside of a chamfered corner. You know how when you use a router to put a chamfer on the inside of a cut-out, there is that little bit where the router can't reach? I do this all the time. I build a cabinet, something with drawers for example, then after it's assembled, I remove the drawer and cut the inside chamfers. These are called masons corners. This kanna will trim the final little bit, right at the intersecting junction.

From the supremely talented Junichi Maeda,  Atelier-M4 blog

When I used routers, I had to finish the corners using a chisel. Bye bye routers..... I'll keep the chisels, though.

I know that my friend wanted one of these for his collection, but I need to apologize for its taking so long to send his way.



  1. For that tiny groove cutting plane, my guess would be a three way joint for kumiko.

    1. Hi zefeng zhang!

      A joinery plane for kumiko/shoji work, would be my guess as well. The width of the blade is about right, for a 2mm +/- joint. I am curious about the angled main blade, though. I suspect that it is the result of inexact sharpening (god knows, I have a terrible time sharpening those narrow blades freehand!), but I can't help but wonder.....

      Thanks for adding to the discussion!


    2. Hi Jason,

      In this video, the presenter uses a jig to lock the kumiko inside and trim its edges. After that, image you want to embed the kumiko into a boundary frame, you will need this plane with angled blade to cut grooves in the frame. Well, it is still my guess.


    3. Thank you for this video (I particularly love the cutting jig)! A beautiful and precise tool can make things look deceptively simple. I also watched a second video of this man demonstrating his work.....

      He cuts some of the joints using a kebiki...... Excellent stuff! It is such a pleasure to watch a skilled craftsmen at work. You are making me want to make shoji!


  2. Oh, by the word "three way joint", I meant this: Then I realized that doesn't explain the angled blade and recalled the video. Also by the word "embed the kumiko", I meant to put this: into a squared outer (picture) frame. But I think you already knew what I mean.

    The craftman uses a kebiki to cut the piece instead of a plane, so I guess he is really a master and self confident.

    PS. This blogger doesn't show my reply immediately. So pardon me for the delay.


  3. This is your small grooving plane. From the Takenaka site:
    (8) Kude-jyakuri-ganna
    It is used for making joints (kude or kumite) of a partition (shoji) or a mullion of an opaque sliding screen (fusuma). Several pieces of a joint can be worked on simultaneously by tightening them together with metal clamps (hatagane) and applying the plane over them (fig.5). The blade width generally ranges from 0.3 to 0.9 cm.

    Fig.5 kude-jyakuri-ganna

    1. Hi Michael! Surprise!

      Kude-jyakuri-ganna was my assumption, and the ONLY thing that gives me pause is that the main blade has been sharpened at a skew. I've cut little tiny sliding dovetails with it but......

      I'm calling it.

      Kude-jyakuri-ganna it is!

      I hope that you like your new/old seme-ganna. Can I show off some pictures now?


Like all of us, I am figuring this out as I go, so when you see something that is incorrect or flat out wrong (and you will!), let me know. This is a learning process. Real people and names, please. Constructive comments and questions are very welcome, but hate speak/politics are not! Life (get one!) is too short.

Thanks, Jason