Jun 01, 23 11:48 PM
by Peter Maynard
I recently purchased a Chinese made wakisashi with a folded steel blade and more or less common fittings. This was my first foray into Chinese Japanese style swords with the intention of the entering the market at a common price point ($150 -$200) to see how they stack up before considering something more pricey. By way of background, some years ago I was interested in rifle smithing - mainly building muzzle loading weapons from parts imported from the USA. This perhaps was 25 years back, in the days before both the internet and high precision computer controlled pantograph machining equipment so needless to say I learned some metal-working and wood-working tool skills including sharpening and polishing.
The wakisashi arrived looking better than I expected (I had low expectations) with a nice damascus pattern but with the usual cheapish Chinese koshirae for weapons in this price point. I knew I would not be happy till I did some work to get everything looking and functioning “just so” (within the limits of the basic kit I had bought) and in particular I knew this thing was going to need some serious sharpening before it would be able to cut as it should. Unfortunately, while the basic geometry of the blade is pretty good to look at it was also by no means sharp enough. Sections of the blade were positively blunt, especially around the habaki area and in the kissaki region. While I was reluctant to remove the damascus pattern I knew this could be reconstituted later by a light etch. The blade sharpness therefore took precedence and a pretty damascus pattern could wait.
The blade has a touch of "apple seed" shape - niku. This meant my normal knife sharpening skills had to be adapted to the needs of this class of weapon. While I have a range of good water stones for sharpening chefs knives (love to be able to put shaving edges on my working blades) I did not trust my ability to use these properly for such a blade such as this which requires a different approach to that I normally use for other edges. So I decided to use a range of emery and garnet papers from 400 to 1200 grit as required. Most work was done with 600 grit as it turned out, with courser grit (400 grit and in one case 360 grit) being reserved for the areas on the blade that were very blunt and required a lot of metal removed. I have done a lot of draw filing, polishing and sharpening in my time so figured that learning a new technique would not be beyond me with a little effort and concentration.
The main disadvantage with this approach is that most metal abrasive sheets of this sort are paper backed and hence need frequent changing. Cloth backed abrasive is better. The other significant disadvantage I foresaw was the question of how to conform to the niku shape while providing some backing to the abrasive so I did not end up with an irregular surface. Even more important this would help control the sharpening process. The first problem was solved when I found some sturdy high quality garnet cloth products with a felt backing in normal emery paper sizes (something like A4 office paper). These are apparently designed for people to be able to cut their own sanding disks to custom sizes. They are correspondingly robust and can be used wet or dry (wet is better) and using light oil or water as the medium.
The second issue was solved when I decided to raid my wife's bathroom cabinet (hence my reference to learning from the ladies in the title). Here she stores a variety of personal kit including flexible nail polishing buffers. The ones she uses have a thin plastic core and some kind of hard foam on either side topped by some kind of buffing strip. They are moderately rigid but still flexible enough to conform to a slight concave curvature of a blade (or a finger nail). Perfect for cutting and polishing on a sword blade with curvature of this sort when using an abrasive cloth as the cutting agent. I also found that it was sometimes useful to have something with more "give" than this. I achieved this by gluing to one side of a nail buffer, a piece of appropriately shaped neoprene cut with scissors from a mouse mat. When the garnet cloth is placed over this it allows even more flexibility than offered by the nail buffer alone.
From there it was merely a matter of slowly working a section at a time and moving along the blade. Long slow strokes worked best. I should add that I fixed the blade horizontally to a work bench (using spring clamps) with the relevant parts of the edge protruding so that I had access to them. This required repositioning the blade now and then.
Most of the work essentially involved a "draw filing" motion (lengthways filing with the abrasive tool held cross ways on the work surface) with one hand holding one end of the nail buffer (wrapped with abrasive cloth) and the other hand holding the other end. Light pressure and some mild rocking motion was all that was needed to ensure even and consistent working of the blade surface. Needless to say the most difficult part of this exercise was sharpening the kissaki area properly. The blade came with a more or less reasonably competently executed medium kissaki, but the edge in this region was very blunt. Sharpening of this section without butchering the kissaki is a chore and involves perhaps the most difficult work of all. The same angle must be maintained at all times and the cutting motion must stop precisely to avoid blurring the yokote – the line where this section starts (the Japanese have a precise name for everything) . I found that a more rigid tool (such as a file wrapped with abrasive cloth) worked better in this region as it gave better control than my ladies nail buffer. My favourite, however was a small "eze-lap diamond hone" which has a plastic body and a small rectangular section of diamond abrasive at one end. It has a nice flat face that the abrasive cloth sits on very well. Once again, abrasive cloth was the cutting medium although I suppose the naked diamond cutting surface of the tool itself could have been used. However, I really did not want to introduce a new set of filing marks to the blade so avoided this as using abrasive cloth with predetermined grit size was inherently more predictable. A few layers of gaffer tape can be used to prevent cutting beyond the yokote line at the end of the kissaki. This seemed to work OK but I think a hard straight edge taped to the blade would be preferable. Next time I might try taping a steel ruler along the blade with the square flat end positioned appropriately to prevent over runs in this region. (If it comes to that, I would sooner mess up a $10 ruler than a $200 blade). If there are better techniques, I would love to hear about it.
I think that is about it - this was a process that took maybe 6-8 hours or so (with a bit of fritzing about, trial and error and reworking thrown in). Maybe next time will be faster. The only other thing I should say is that a final polishing was achieved with 600 grit cloth carefully executed along the full length of the blade in long even strokes. I believe that you do not need to go to a mirror finish and in any event that is very difficult to achieve as small cross scratches seem to creep in at every opportunity. Besides, acid etching to re-establish the damascus pattern (which is yet to be done) will undoubtedly give a satin effect on exposed areas of the blade. What counts is that there is an even finish on the blade.
As for the edge. Yes this approach worked well as a means of sharpening a well hardened blade (most likely 1060 steel) of this type. I can now happily shave hairs off my arm and slice paper in the time honoured fashion. Would I try this with an expensive blade, especially one with a hamon or God forbid a real Japanese sword should one ever come my way? I somehow doubt it but I figure that in this case I had little choice and even less to lose. One final thing. While cutting with emery / garnet papers did seem to work quite well, this blade did seem to be reasonably well hardened. I only know this because I decided that the mekugi hole in the tang should be slightly chamfered to make removal and replacement easier. A high speed tool steel chamfering bit hardly marked it. Yep I think I can say its hard.
Good luck all - just remember, use slow, long even strokes and concentrate, concentrate, concentrate. I have also found that when sharpening knives, the moment I lose concentration is the moment I cut myself. About a year ago I very nearly removed my thumb just like this. But that is another story.
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