A gift for a friend-----refurbishing a seme-ganna Japanese plane

I've been building some stairs, to access an attic bedroom that we built only, what.... 6 years ago! Already? The ladder that we had been using had it's charm, but I think that the renters of our house might want something a bit more traditional.

Treads in the works.

And.... A gift, for a friends collection, a seme-ganna.

At long last, here it is.

From this......

.... To this

I would like to tell you about how difficult this project was, all of the interesting little details and tricks that make these projects so gratifying, but......

This was super easy. A light surfacing, to remove the ubiquitous red Japanese paint (My friend Brandon says that every old american tool that he buys has spatters of white paint on it. The Japanese tools that I buy have red. Huh, Go figure!), left the wood looking wonderful.

There was some iron staining around the mouth (What have you been eating?!!) and top of the dai. This is simple to remove, using a phosphoric acid solution, typically sold as a paint prep for rusty metal, or an etchant/cleaner for ceramic tile. Swab a little on the dark areas and it will fade away in 15-30 minutes. The acid is very mild, no worries (I mean, don't drink it, or anything, but...), and doesn't discolor the wood.

The irons were a pleasant surprise. They are virtually unused, and only required a minimum of attention. I gave them a brief traditional rust bluing, to even out the slight amount of discoloration from the surface rust.

The surprise was that the main blade was forged from ren-tetsu wrought iron (unusual for this size of blade), and even more surprising was that the sub-blade is laminated as well (definitely not what I was expecting).

Notice the dinged up corners?

The ren-tetsu is very nicely layered.

Unfortunately, as I was removing the blades to photograph them, haha! Dropped!

At least we know that the  hagane isn't brittle hard, eh Michael?

So, off to the stones for a very quick touch-up. This was done rather late in the evening, so I did this old-school (no power, just muscle).

My stone sequence for this quick project.

Two cheap China diamond stones (mounted by me on wood bases), a strangely discolored white aluminum oxide based man-made waterstone (probably a King Hyper, and rapidly becoming a favorite of mine), and two naturals to finish things up.


The stone on the left is an aoto of some sort. It is relatively soft and serves to ease the transition, from the deep angular scratches of the artificial stones to the shallow, gentle scratches of the natural finishing stones.

A quick way to evaluate the relative hardness/softness of a natural waterstone, is to dab a bit of water onto it's surface. The softer stone quickly absorbs the water, while the hard stone absorbs little or none.



The choice of a hard stone versus a soft stone is rooted in some very interesting physics. I'm not going into that now, but it's something that I am trying to get a better grasp of. Later....



Because I mucked up the blade pretty well when I dropped it, I need to flatten the edge first, using a diamond stone.

The newly flat edge is uneven, because the blade had been partly skewed. In for a penny.....


I reset the bevel, using #80 grit 3X sandpaper (a 3M product), mounted on glass.

Yes, that is a sharpening aid! I'm feeling lazy. They aren't worth a crap for Japanese plane blades, but for narrower stuff they can be damn handy.


Instead of letting the burr form and fall off on it's own, I have begin removing it as I go, using a fine grit stone.

It takes a few moments longer, but *maybe* provides a stronger edge. We'll see. My thought is that the burr falling off on its own, is due to metal fatigue, and work hardening is not what you might choose for a durable edge. This idea isn't original I'm sure, but it is something that I want to try it out.

 It's nice to have stones large enough to use with a guide, if needed.



The hard Ozuku asagi gives a really nice finish to most blades, and is one of my favorite stones. You can really see the beautiful layering pattern in the wrought iron.

This blade is also a bit unusual, in that the stone gave the wrought iron a bit of a purplish cast. Every one is different. I love it!

Very close to a full mirror polish. It's funny that these cameras make it so difficult to for me to get the photos that I DO want (I want a macro shot of the layered jigane), but give me many pictures like these.



Here is where those stair treads are going. Obviously a closet (at least, it was.).

Thankfully, there is ample feline supervision in our house.

Cat tested.

Diamond everywhere! Testing some cheap diamond files for sharpening

More sharp!!....... Inexpensive , China made, diamond tools for sharpening the hardest Japanese tools. It's amazing how cheap ($) this stuff is getting.



I had bought a set of small detail bits suitable for a dremel type tool (1/8" shank). They worked well, and proved sufficiently durable, that I bought a larger set (1/4" shank).

Set of six, 1/4" shank, $11. 

I specifically got these for carving out profiles on some small kanna blades, used for cutting edge profiles. They seem to work just fine, the diamond grit is evenly distributed, and well adhered. If used with a light touch, these should give a respectable service life.



It’s pretty much impossible to determine *exactly* where any of these tools are made, so performance is unpredictable. At the other end of the performance spectrum are these diamond fingernail files. Diamond tools are everywhere!

4 For $1(top), and $0.99 each (bottom)

The upper package was found at the $Store (4 files for a dollar, I used one already.) The two at the bottom are $0.99 each at Walmart. Shockingly expensive, haha!

The $0.99 files are small, cheap ($), and cheap (quality). They work, to a limited degree, but lose their abrasive qualities rather quickly. #220 grit or so.

New on top, and after a few minutes of light work on steel (bottom).

They would probably work just fine on fingernails, but I'm using these files for harsher duty. Japanese plane blades, high carbon steel, HSS......whatever is too hard to sharpen with a standard file. 

The file on the right hand side is one of the cheapest-of-the-cheap $Store files. Larger, slightly more coarse (#180 grit), better looking and grit on all 4 sides. I was psyched to find these at the $Store, but they only had two packages remaining. I bought both!

$2 wasted! Service life can be measured in strokes, 1-2-3-done. I suspect that the file blanks are dipped in diamond fortified paint, as opposed to being electroplated. One file has a coating that stripped entirely off, after only a few minutes of VERY ineffective work. 

So, from the left, we have new $0.99, used (smooth feeling) $0.99, and $0.25 $Store file. 

Unfortunately, none of these are worth buying, even for a cheap guy like me.


For $11 (free delivery), these diamond files are 3" working length, come with 6 grits, and feel very durable. The electroplating, particularly on the scary rough #40 grit, is thick and holds up in use. These files work.

As the tool breaks in, more diamond surface is exposed, and the file becomes more effective. On short acquaintance, I am pleased.


I don't know much about Japanese saws, but I'm getting there. I bought a beautiful little $12, traditional 75mm yasuri feather file from eBay seller: Sakura-pink, to compare against a cheap ($11+free delivery) China-made diamond file.

Not my file-work, BTW! This saw is still fresh.

The sizes are comparable, but the "real" file has a slightly finer profile, and is MUCH faster in use. We shall see which is longer lasting.



About 8 years ago, I bought this knife sharpener at Walmart, for about $12. It has seen VERY hard use, and still works well. Some of this cheap China stuff is pretty damn good.

All diamond tools settle in after a period of time, sometimes minutes, sometimes months. This thing mellowed out after a few weeks, but then...... just won't stop working.

Coarse on one side, fine on the other. The fine is now around #600-800 grit.




If you have some serious metal to remove, but don't have access to a grinder, here is one way to do it by hand.

This kanna blade has had some serious ura-dashi done, and needs to start looking like a cutting tool again. The flat tip is nearly 1/8" thick..... That's a lot of steel to remove!

I tape a line, to act as a guide for establishing a new bevel. Most of the material to be removed is soft iron, so I can use a standard bastard cut file to hog out the bulk of it.

I love working this soft stuff. This only takes 2 minutes.

You can hear the difference, once you get to the hard steel lamination line. Stop, before you ruin your file.

Then use the diamond file, but ONLY on the hard steel portion. I have found that soft steel and iron can strip diamonds from the file (not these, but other diamond sharpening stones, so....), so ONLY use diamond on the hardest materials.

Finally, I finish the bevel using sandpaper stuck onto glass. This establishes a final, level surface over the entire bevel.

The 3M 3X line of sandpaper comes in funny colors, and uses a ceramic abrasive that fractures down nicely in use. It lasts WAY longer than the other common abrasives (al-ox, silicone-carbide, etc.) and only cost slightly more. Money well spent.

Although this was an extreme example, this blade only took about 15 minutes to get to the stage where the sharpening part starts. That's not bad, by my book.

I could've used JUST sandpaper (the good stuff)...... Maybe 2 sheets (so, $3 for sandpaper) and 30 minutes time. It *feels * like harder work, though.

SK-11 diamond sharpening stone and some $store surprises

Planing away, hard at work building a deck, I am having some issues with edge retention. I don't know what it is, but there seems to be one board in this batch that has some serious abrasive qualities. It's like it's filled with sand or something (not that living at the beach has anything to do with that, or.......).

You see all of those nicks? They weren't there a few seconds ago. In any event, it's time to sharpen. Again.


First, a surprise.

The other day, I was wandering the isles, looking in some unlikely places for some diamond grit abrasives (More on this later). While I was at the $Store I found, of all things, a sharpening stone.

How bad could it be? For $1, expectations are low, but I was actually quite surprised. This thing works! I soaked it in water for a minute and used it like a waterstone. One face wasn't perfectly flat, and it is a touch soft, but....... This bugger cuts! 6"x 2"x 1" of steel eating fury! This blade is one of the hardest ones that I own, so the speed is even more impressive.


With two faces, it is ostensibly a coarse/fine combo, but I didn't see much difference, to be honest. The coarse side is softer than the fine. It is noisy. Crunchy sounding. The coarse side is soft enough to make a little bit of mud, which seems to speed the grinding action.

Did I mention that it is soft? Being soft, it will require regular attention to keep it in the realm of flatness. I need two.


There is an antique mall/ flea market kind of place here, and way in the far back corner, there is a booth that sells tools. The cheapest of the cheap, but I've found some decent stuff there. They ALSO have some sharpening stones, and they're even cheaper than the $Store.


I splurged and got the big 8"x2"x1".

$0.75 (The 6" one was only $0.60, haha!).


Like the smaller stone, one face is slightly dished, but only by  .15mm.

The cause of the dishing is a bit of a raised lip around the perimeter, a remnant of the molding process.

Bevel the edge, and it will be almost perfect.


The other face is as flat as I can measure. A 0.038mm feeler won't fit, and that's the limit of my measuring tools.

Good enough for me. It will go out of flat in use, anyway.

This stone is harder than the one from the $store, more like a traditional oilstone.

Being harder, it is also slower. It is possible that using this one with oil would improve its action. This stone wouldn't have any problem with your average western style mono-steel blade.


The fine grit side would bring the blade to a near-mirror finish, given enough patience. The softer expensive ($1!) stone has spoiled me!

I never would've thought that the $store would have sharpening stones, much less ones that work. I've been looking for a coarse grit stone that works tolerably fast, and this one is nearly as quick as using the belt sander! Now if only I could find one in a 8"x3" size......


The ura on this blade is starting to encroach on the edge. Time for a little bit of ura-dashi.

A new weapon in my fight for flatness, an SK-11 diamond grit sharpening stone, bought from eBay seller: Sakura*pink. The stone is targeted towards  the Japanese market, but is made in China.

I've bought from him before, and he has always been patient with my utter lack of Japanese language skills, helpful in finding stuff, and very good at getting the best shipping price (and refunding any extra!). A great seller!


The stone is 204x65x7mm, and VERY heavy. It's over 1/4" thick.

The embossed pattern is #400 grit one side, #1000 grit the other.

The #400 grit side is flat. The #1000 shows a bare sliver of light under the ruler, but the gap is less than I can measure (so less than 0.038mm). Both sides are absolutely flat along the short axis. This stone is light years flatter than any american made diamond stone I've ever owned.

I want to focus on just a small area. It is easier on the blade (and me) if I do a small bit frequently, rather than waiting until it becomes a large endeavor.

The ren-tetsu is nice and soft, making ura-dashi fun. Just this little bit of tapping, using my modified track hammer, displaces the soft iron and pushes the hard steel down.

Sighting along the cutting edge, you can see that the edge has been deformed, resulting in a small bulge to the left.


The bulge gets ground down. That's why I bought the SK-11 stone.

These stones have a reputation for being only a short step down from the Tsuboman Atoma stones, and at 1/2 the price (or even less. Sakura-pink sold me this one for $35! A great guy!). This is what most of the Japanese guys use, particularly for waterstone flattening.

With judicious tapping, I am gradually evening out the flat area, just back from the cutting edge. 

Each time I do ura-dashi, the shape gets a bit better.

On the bevel side, the hammer marks show how the displaced iron actually pushes the steel down. You want to do ura-dashi before grinding the bevel, sharpening the blade.

From this point, it's sharpening as usual.


Ura-dashi adds some extra work to the sharpening process, but the new diamond stone works quickly. The finish is still rough, much coarser than the grit numbers indicate, but that should mellow with use.

The quality of the SK-11 stone isn't perfect, but it's pretty darn good, MUCH better than I was expecting, and far flatter than anything made in the good 'ol USA. I plan on using this stone with the lightest touch possible, in hopes maintaining its speedy cutting action. Most important to me, though, is that it's flat. Why can't WE make good stuff?