Hello and welcome back to my blog. In this series I will be preparing a Kanna (Japanese hand plane) for upcoming work. The kanna, by Nakano with a dai cut by Inomoto-san is newly made but not quite ready for use. High quality preparation of this blade, made of Hitachi white steel 1, will allow it to take an incredibly keen edge. I’ve created this post to help demystify the process of kanna prep by detailing the steps I take in preparing a new blade for its long life planing wood.
I start preparing the blade by working the back, called the ura, to create a flat perimeter around the urasuki (hollow). Japanese plane blades are made from very hard steel. To allow the maintenance of a flat back the blacksmith will grind a hollow (Urasuki) into the back. The blacksmith flattens the outside perimeter (Uraba and Ashi) which is then maintained by the user for the life of the blade. Good maintenance starts with good prep.
I begin this process by checking the blade on a true flat surface for teeter-totter. Where the blade pivots are high spots.
These high spots, if one were to simply start abrading the back, would create an uneven ura and therefore much embarrassment whenever I show photos online. I adjust this by first working the back on my anvil using shims and a wooden drift pin. I can deform the back of the blade, constructed of soft iron, which will then deform the hard steel back. Now I can’t go ahead and beat on the hard steel….that would not do well. Instead, I use a wooden drift and I apply force to the center of the back. With shims at the low corners I will ‘adjust’ until the blade sits flat without teeter-totter.
The blade now sits flat, still I am not ready to grind away carefree on the ura. I preparing a 1000 grit synthetic stone for the work by flattening it and checking it to ensure it is flat with a precision straight edge.
(1/2020 update: I now do this process as depicted in On Ura-Dashi: Ito-Ura) using ura-dashi and a fine stone a neater ura can be made.
My next step is to begin ura-oshi by lightly working the back on the stone.
As an aside I feel it is important to understand that synthetic whetstones literally go out of flat as you use them, so as soon as the show steel particles on their surface I will stop to resurface them flat again with an Atoma diamond plate. Maintaining consistently a flat surface will allow my results to be reliable.
Now I can see an area along the center of the uraba which is not contacting the stone. If I were to continue then all areas of the flat would begin to grow in size, except this area, making for an uneven ura.
To remedy this I use a process called ura-dashi, or ‘tapping-out’. I perform this process by tapping, with a hammer, the soft iron of this blade. It’s very critical not to hit the hard steel or lower half of the bevel nearest the hard steel which would break the blade.
Now I go back and forth between ura-oshi and ura-dashi until the full perimeter of the ura contacts the stone evenly, noted by an even scratch pattern.
Next, I move to the 3000 grit stone.
Followed by 8000 grit.
And the resulting ura.
Maybe you are wondering….but where are the Jnats! They are to follow, but first I grind the bevel. I begin work on the bevel with a rough stone. Removing the marks formed by ura-dashi takes some effort.
The bevel is hardly flat at this point, mostly because the low grit synthetic stones, while fast cutters, go out of flat very quickly. The stones which progress after this point will help to make the bevel progressively flatter. Starting with an 800 grit stone I will flatten the bevel and remove the convexity created by a rougher stone.
Maintaining flatness starts at the roughest grit. As I progress to finer stones, loosing flatness becomes seemingly easier and regaining it significantly harder.
It’s critical to keep an eye out for inconsistencies, to highlight low spots I change the direction in which I’m honing. I change the angle enough with each grit so that the scratch pattern of each stone is distinguishable. In the photo below, I’m pointing out a section which is low.
Next I work up through to a 3000 grit synthetic. The finish on the bevel is quite nice at this point.
Finally I can move onto the Jnats. Starting with the Yaginoshima asagi which is a stone that does not dish easily, then move onto the Shinden suita and finally the Nakayama asagi. I repeat this same series on the ura.
I check for flatness with a straight edge in both directions.
I begin a similar process on the chip breaker. First I check the fit against the plane blade and adjust to suit.
I process the chipper using ura-oshi and ura-dashi, as I did the iron, then I work the bevel flat.
Next, I follow this by standing the chip breaker up on the stone. I then grind a very small microbevel at 70 degrees.
And the resulting microbevel.
That’s all for now, in the next post I will begin fitting the blade into the kanna dai.
I owe a debt of gratitude to Chris Hall, So Yamashita, Stan Covington and David Weaver. The insight they have provided me is both boundless and greatly appreciate.
I hope you have enjoyed reading, please comment below!
Thanks, I will be following along. I’ve a couple of Kanna Dai needing to be fitted once I’m two armed.
Good to see you here on the blog! Excellent, also glad to see that you will be following along.
Like Kenneth, I have a Kanna Dai that I need to fit. My wife gave me a Kanna several years ago, but it has been sitting on a shelf in my workshop unused. I have been reluctant to tackle the fitting for fear of ruining it. I’m anxious to watch you perform this task. I hope to be emboldened to tackle it myself. I’m grateful for your blog. I enjoy it.
Thank you for your comment! Glad that you enjoy the blog and that you will be following along with this series. Fitting the dai seems a bit daunting at first, and originally was for me as well, but it gets easier every time.
Thank you for the excellent blog. I recently purchased my first Kanna from eBay that needs proper setup. I will be following along as I do my own. Also, I have enjoyed reading all your other posts. I appreciate your style workmanship. Thank you.
My pleasure! Thank you for following along and I’m glad that you are enjoying.
I would like your insight about sigma power ceramic stones if you know anything about them in comparison to the shapton pro series I’m currently using. In the past I was using Norton stones which served me very well for a number of years. As you know until recently I was a professional woodworker working mostly 7 days a week which meant sharpening my tools several times in a day was the norm. Eventually but after years of usage they wore away and my supplier switched to shapton. Not knowing anything about shapton I took his word that they were longer wearing and cut faster than the Norton which I found none to be the case. I realised by now that these suppliers usual clientele are hobbyist so their tools do not see much use. Now beng a amatuer hobbyist I too fall into this category myself. However a saw maker I met recommended to me the Sigma power ceramic and I watched a video on them in use at toolsfromjapan.com I’m reserved; once bitten twice shy as they say about these stones and any other than the Norton I’m acustomed too. As stones are not cheap testing different ones to get a good insight on what’s good or not isn’t a financially viable option. So I ask you if you know anything about them to give me some level of insight as to their quality and wear. Also I noticed your stones are very thick which I haven’t seen before, where did you get these stones and how would you rate them. Much obliged for your help if you can.
Good to hear from you!
I can’t speak specifically to Sigma power, or even Shapton Pro’s beyond the ones I’ve used. I have a Sigma 13,000 and it’s a great stone but not one that I use regularly. I also have a Shapton Pro 320 grit stone, which is very friable and not likely to be a good representation of their line up as a whole since rough stones are usually quite different in character from fine stones. I use the Sigma 13,000 for the odd few tools that I have in Super blue and A2, both of which are highly resistant to wear and so that stone and the stones which lead up to (Chosera) are geared toward cutting it.
The Naniwa Chosera stones (1k, 3k) along with the Naniwa 8k ‘snow white’ and the sigma 13,000 serve me well, but since I do not have a shop sink, at current, I’ve moved toward stones which do not require constant flattening for my everyday use.
For the steels that I prefer to use most often, which are plain high carbon steels and simple alloys, Norton India stones are perfect, they remain flat very well and cut fast enough that the work moves along at a good rate. Those stones are especially thick because they are double sided (one side is coarse and the other is fine).
I understand your hesitation with wanting to experiment, you can fall down the rabbit hole as they say and up end trying one of everything.
Thanks for your reply Brian, I guess I will give Sigma a go then since all my blades are A2 and takes considerably longer to sharpen than carbon steel would. The shapton pro 220 grit is more hard wearing than the rest. I definitely will give those Sigma’s a go if it fails then I’ll go back to Norton and stick with them till I meet my maker.
I should have added above; I also work A2 with India stones and it cuts fine, probably not as fast as a synthetic water stone, but fast enough for me, however that is in the rough grit range, once you move to medium-fine stones then stones that I prefer to use are not entirely effective against A2 so often enough I will use the synthetic water stones from that point.
Norton seemed to to cut the fastest in comparison to shapton and dished out less in fact much less than the shapton. I just have to look at the shapton and it hollows out.
My experience has mirrored yours. The Norton India stones I have can remain flat just from lightly working them with a 140 Atoma….I check them with a Matsui straight edge on occasion and they’re always flat. I had a good laugh at your comments WRT the Shapton, not long ago I described my 320 with the exact same comment. I was concerned I would wear it out in record time just from flattening it.
Too true when in use they dish out very quickly and fairly deeply but flattening seems to take a bit longer therefore wearing them out quicker. I’ve only had them for a couple of months and in the first week I thought they wouldn’t last no more than 6 months but now since I’m not using them everyday I believe I can stretch them out to 12 months but I will prepare myself and buy those sigmas as reserves. I certainly hope that the sigmas are better than the nortons as they are cheaper. Time will tell though.
I think they’re probably do well. So Yamashita has commented positively on them, and if So likes them they’re likely very worthwhile, I’m curious to see how you like them after some time on them.
I am/was equally worried about wearing out that Shapton quickly.
I only need to use a stone one time to see its worth but you could be right they may also be very soft and wear out fast.
Sorry about that, I meant to say Shapton referring to the 320. I edited my previous comment.
I understood anyway all good brother
Beautiful blade and uchiba. Nakano san makes a great blade, and yours has some beautiful jigane.
The name I was taught for these planes was Goro ganna. Not sure where the name came from. Hikouki is a much more poetic name! A Plane plane!
Look forward to seeing the progress.
When you get around to it, please show us your planing beam and stop. Very important when using this particular plane, as you know.
Good to hear from you! Thank you, I’ve got the plane setup as a normal finish plane for the moment (I plan to use it for that Kezurou-kai, rather than the Togo-kou Yokoyama, since it is white steel) and it has really proven a wonderful blade.
Thank you for sharing the proper name. I found it being called Hikouki by Des King and Tomohito Iida, but both are referring to the same Inomoto made version, so it’s possible that it’s Inomoto-san’s nickname for the plane……or I could be creating a rumor. 🙂
Certainly will do, I’ve had to make quite a few adjustments to my ‘planing beam’ aka the far side of my bench, and it’s flat enough for general purpose but won’t do specifically for this. It’s my understanding that the planing beam must be very precise for this work and so my plan is to build a track specifically for the kumiko work which will work in conjunction with my setup but provide better support. Any thoughts on this?
The top surface of the planing beam or workbench needs to very flat and true. It needs to be consistently hard. For instance, Douglas Fir works perfectly for most things, but the summer wood wears away leaving ridges of winter wood which can can leave narrow delicate kumiko unsupported unless the DF grain is very tight. Maple or white oak are good choices. The plane’s skids tend to wear grooves in the planing beam/board after a few thousand passes, so hard is good.
The stop needs to secure the ends of the kumiko so they don’t ride up. I assume you will thickness plane 2 or 3 kumiko at a time.
Are you going to make plain rectangular cross section kumiko, or the more refined mentori (chamfered) kumiko? If mentori, do you have a kudegoshi and a suitable chamfer plane?
Thanks for your guidance, much appreciated! I have been considering white oak for both the track and the skids, I’m thinking that I will put the flat sawn face up. I have some lignum vitae that I had been considering for the skids, but unfortunately it’s just short of what I needed.
I was also thinking to do two or three at a time, so I plan to incorporate a stop that will bite into the front of the kumiko slightly.
I’ve planed on mentori kumiko, as I hope to impress my wife with these shoji so that a few more might appear around the house without much resistance. 🙂 I have a chamfer plane, but I’m without a kudegoshi. Also, I was hoping to ask your advice on a Ha-ganna.
Did a little more websurfing, and found some other references to hikouki kanna. Idunno. The old boys I learned from called it a goro ganna.
I made two of them for Mr. Honda to inspect back when he was giving me homework assignments. I screwed up my first effort. I still have the second attempt (Yokosaka blade), and it is a real hummer. Here is what he taught me.
The first point is to not cut the mortise for the pressure bar full width of the sole, but to leave the side walls uninterrupted from top to bottom. You want those continuous fibers at the sides to keep the plane from warping and flexing. The pressure bar will stay in place just fine secured by a recessed screw at each end.
The second point is to resist the temptation to use wedges and lock screws and other varieties of adjustable skids. The adjustable kind make perfect sense, but since they wear out rather quickly, it is better to just cut two sticks and screw them to the sole. KISS. In any case, after being told this I never even considered making one with adjustable skids.
Honda san was big on extreme accuracy with simple tools. The results, which decorate several major museums in Japan, speak for themselves.
Thank you for your insights. I had planned the adjustable skis, but I will do this the way that you were taught instead. One thing I’m still unclear on, and if you dont mind me asking, what did you use for springs? I’ve been considering flat metal springs, but if you are attaching the pressure bar with inset screws then perhaps you are using coil springs?
Not sure what you mean by Ha-ganna, unless you are planing on incorporating kumikozaiku in the shoji. I don’t recommend it for your first adventure.
Here are some pages with images of kudegoshi and the jigs required to use one. I have one by Yukichika back in storage in the States. Not sure where one could buy one for less than $500 nowadays.
The same thing can be accomplished with jigs and a sharp chisel, but equal precision and speed would be difficult. Of course, commercially it is done with routers in production shops.
I had been contemplating a more heavily patterned waist panel, but I’ve come across a few images that show a similar visual effect and that do not deviate from using rectangles, so I’m leaning toward those. Probably best to keep it somewhat simple for the first endeavor.
Thanks for sending over those links. That looks like an ingenious type of device, I see it helps make quick(er) work of certain patterns.
I used a metal plate spring. It is an arched spring used to keep the sliding lower panel in yukimi shoji in place. It applies pressure at the center of the pressure bar, and therefore, I was taught, is better than coil springs.
Every tategushi had boxes of these springs on hand. I don’t suppose there are many yukimi shoji made anymore. I can see if my local hardware store has any collecting dust on a shelf if you want. They just might.
But I see no reason why two coil springs around the screws would not work just as well. They are easier to find nowadays (not so when Honda san was making goro ganna) and last longer than plate springs.
Thank you again for sharing your experience! I appreciate your offer but I will give the coil springs since they’re easy to find locally, and report back.
Excellent write-up and photos. I have not tried “thumping” a warped blade yet. I’m sure the process is exciting. Is the chip breaker you have the type with bent ears? I am not exactly clear where you are hammering. Assuming the chip breaker is not grossly out of flat, I generally will carefully stone the high ear to adjust them. Did you also grind the blade to match the width of the chip breaker? I try to make the blade slightly narrower than the chip breaker so I can more easily see the chip breaker when setting it close to the blade edge. Of course grinding the blade is probably not necessary for use in your hikouki kanna.
Good to hear from you! The process was very exciting the first time, but more scientific this time around. I had to do the same with pretty much all of the blades, except the smallest one. The smaller the get the mort difficult it is to effect change. The chip breaker on this one is a hand hammered type, so deforming the ears slightly settled the blade to remove any rocking, it was a similar effect to filing but I figured it would blend in with the original hammer marks more so than filing would.
Exactly right, I left it as wide as it arrived since I would like to be able to use the full width….or nearest to the full width as possible. Ideally a little bit of the ears will tuck under the runners.
Looks good. I would love to see some pictures of the bottom of the plane, if possible. Thanks!
Thank you! Absolutely, in the next round I will show the bottom of the plane. I leave the mouth extremely tight, usually increasing the angle of the wear rather than opening the mouth if shavings won’t feed through. In the case of Japanese planes, since they are used on the pull stroke an open mouth will cause snipe on the end of the board. I had this trouble with my Kunio plane and then had to fix it with a dovetailed bit.
Where did you learn this process, particularly the tapping out section? I have been using Kanna for many years, but I have never felt confidant enough to buy a good plane because I don’t know the process of fitting the blade to the Dai, nor the method of preparing the blade – or tapping out. I would really like to find a good class on the subject somewhere.
As always, your work, your blog, and your SMC posts are fantastic. I really watch for your name to come up on that board.
Good to hear from you! I learned through reading many blog posts, books and asking advice from Chris Hall, Stan Covington, David Weaver, So Yamashita, and Yann Giguère. Desmond King’s book number 1 on Shoji is wonderful and has a very comprehensive walk-through, Toshio Odate’s book is also very good. Chris runs a class annually or semi-annually in MA, so if you travel there for any reason his class is likely quite enlightening.
I’ve never taken a class in woodworking (past high school) but for the first time I will be taking one at Mokuchi in Brooklyn, NYC in a few weeks run by Jim Blauvelt and Yann Giguère. I couldn’t pass up the opportunity to hang out with a bunch of Japanese tool nuts for two days. Jim has forged his own blades and cut his own dai, so I’m looking forward to see what he has to show.
Yann runs classes regularly, so if you travel into NYC area I think he would be worth looking up.
When it comes to tapping out, I have a metal working background so it didn’t make me overly nervous compared to other metal working tasks but I proceeded at first with extreme caution. The key is to understand how to backup the material with the anvil and to strike accurately. Hitting the hard steel will end in disastrous results and improper backing can do the same, so it may be worthwhile to practice first on some metal cut offs to hone your accuracy and understand the process.
You may also want to look up Kezurou-Kai USA, as they are on your side of the US and might have classes more local to you.
Thank you for your comments!
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Great write-up as usual Brian. Appreciate the englightening post.
When you make a pass on your clear Cordovan strop, is that to remove the burr? Do you draw only the bevel along the strop? My sharpening process for my western tools has not been refined to the level of yours. Obviously no hollows are intentionally implemented on western chisels or planes (that I know of). Every time I see metal “tracks” showing on my Shapton stone faces, I should level them, before proceeding again? My sharpening is not at the level I would like, any responses are helpful. I’ll continue to follow along as you continue to post, and I keep up with your Instagram similarly.
Hi Brad, Thank you for your comment. I no longer use a strop, I make certain the burr is totally removed by the finish stone. Hope this is helpful.
Thanks for the response Brian. When removing the burr you’ve raised, do you make a few passes on the bevel, and then a few strokes on the back face, chasing the burr until it eventually feathers off? Or do you continue to abrade the main bevel only?
A strop will be removed from my sharpening routine now, as a test. My final stone is a 12,000 Shapton. Abrades well in my 01, A2, and PMV-11 tooling.
Well, Japanese tools are extremely hard so the burr is very small by the finish stone and so easily removed. I don’t have to chase it off.
When working A2 and O1, you do chase the burr off as described?
I noted above that you do use some A2 tools. In your experience, which stones do you prefer for higher grits, after moving from the Norton India stones?
I should perhaps update this post, I don’t use oil stones very much anymore. I own precious few A2 tools and I typically use synthetic water stones on them.
I teach classes, if you are local it may be worth it for you to come out to a class and I can detail proper method (in my experience).
Brad, I made some quick updates to this. Check out my ito-ura post also. Btw I removed the A2 blades from my LN planes and replaced them with O1 and Blue steel. Both of which work fine on synthetic and natural stones.
The burr on A2 is very durable. You may need to chase it off, I typically do this on a stone but a strop can work also.
In this post – from four years ago – you describe using india stones as your rough stones, but then in the comments section you mention that you’ve since moved away from them. Do you now use the Naniwa Pro (aka Chosera) 800 grit stone as your coarse stone, or something else? And how does what you’re using now compare to the india stones that you moved away from?
Good morning! I’ve moved to another approach, I start with a 400 Grit Chosera followed by 800 Grit, then 3000. After which I sometimes use a synthetic (8000 or 13000 or both) and/or a natural stone or two. All depends on the steel and goal of the sharpening, IE some sharpenings don’t requite extreme detail and others do.
Thanks! How does your new 400 Cho – 800 Cho lineup compare with your old coarse india – fine india routine in terms of speed and flatness? This is probably very interesting to a lot of people because standard operating procedure below 1000 grit these days seems to be diamond stones, but those have durability and surface uniformity issues of their own. I think you may have a monopoly on information about low-grit alternatives to diamond stones.
Happy to help. The new grouping is considerably faster. I won’t use diamond stones on steel/iron directly, only to flatten stones. The Chosera line-up is great, very easy to keep flat and fast cutting.
Hi again Brian,
Sounds like your new lineup is working very well. I just wanted to follow up and ask what you do if the Cho 400 is not rough enough. Do you use a tormek or some other form of grinder?
It is working great, thank you! I normally do not need to use anything rougher than 400 grit, on a rare occasion I will use a bench grinder, very very carefully.
I do teach classes on this subject, and I’m sure to be doing another one online for Kez-USA in the next few months.
First; thanks for this informative blog.
My woodworking started in the days before the availability of, in the west, today’s overwhelming variety of sharpening stones and methods. (not to mention the availability of Japanese tools.) Sharpening was corundum, followed by hard and soft Arkansas, and leather. Still the only stones I possess. I call today’s sharpening “The Era of Flatness”, something that the earlier era did not produce. Now this old dogs is feeling the need to learn some new trick; i.e.; transitioning to Era of Flatness tools and techniques. This will be expensive, and I am researching before taking the plunge to buy stones and such.
I am considering two different methods.
1. Diamond plate (DMT) for initial flattening, followed by synthetic or natural for finish.
2. Shapton, followed by synthetic or natural for finish.
The diamond plate method to avoid the continual flattening of the wearable stones.
I read you do not use diamond the tools directly, only to flatten. Can you explain why?
Any comments or suggestions re/ which method is preferable.
Or suggestion for a basic setup of stones to sharpen nomi and kanna.
The goal is kanna sharp enough to do finish planning.
Hi Pete, I use diamonds only to flatten the sharpening stones. Diamond plates otherwise lose their aggressive cutting ability rather quickly and the type of cut they produce creates a scratch with a deep valley. A ceramic or natural stone produces a groove with a rounder or rounded valley respectively. This is going to produce fewer stress risers which lead to edge degradation.
For ceramics my current set are from Suzuki Tool and they are great. My current diamond plates are from nano-hone. They are fantastic.