Friday, November 13, 2020

Iaito Reborn As A Wakizashi Part 3

So after getting off all the epoxy, glue, and lacquer off my skin from last week , it's time to get the tsuka (hilt) done.

Before you glue the tsuka halves together, keep fitting the nakago (tang) until the proper tightness is achieved. The blade should NOT be easily shaken off and only by using the proper technique for tsuka removal (Google or YouTube it) will the blade come off.

After the glue is set, plane down the tsuka until the fuchi (hilt collar) and kashira (buttcap) fit. Depending on the fittings you choose, there may be a small taper in the tsuka shape.

If you shake the sword and the blade flies off and impales someone, you've chiseled too much. 

 

By now, you should've already sprayed at least a coat of acrylic enamel on your saya (sheath), which usually takes a week to fully set for the next coat, after which it's a good time to check up on it.  There are likely surface imperfections from runs, as well as from any little dings and scratches on the saya itself.

Use VERY FINE sandpaper to smooth out the coat, and, depending on how deep the dings are, you may not be able to get all of it off. That is fine, just put on several more coats and repeat with the sandpaper and they should disappear.

With a week between each coat, "lacquering" the saya is the most time-consuming and is why it should occur concurrently with work on the other parts of the sword. The more work you put in though, the likelier you will be rewarded with a nice shiny finish.

On to the samegawa (AKA "same"). A good, big fat same will have big fat nodules on the skin surface, as well as a big fat price tag. Since I've already donated all my kidneys to fund this project, I've opted to turn to eBay to procure one of the smaller specimens from China.

In case you have any issues with this:

  1. Given the small size of my project, I can make full use of a smaller same,

  2. Using "authentic" Japanese materials is not an issue here - a stingray is a stingray, and they can freely swim between Japan and China anyway.

Also note its "bellybutton", which is the large node in the middle called the "emperor node". More on this later.

You will need to measure out and mark how much to cut. However, chances are your same probably came in the mail all curled up to save space, so you will first need to soak it in water until it's soft as vinyl, and then dry it out flat.

Easier said than done, since when it dries, it curls up like cooked squid, except imagine the squid curling up so hard that it crushes your wok into a cannonball.

This is actually a desirable property, as when it curls up against your tsuka, the same will add a considerable amount of structural reinforcement.

One way to dry the same flat is to clamp the same by the edges onto a badminton rack.

An alternate method is to use two stacks of heavy books or C-clamps to pin down the sides - just keep the midsection of the same exposed in order to air dry.

If your same is thin enough, you may be able to cut it when it's dry, otherwise you'll have to cut it when it's soft and wet. You will need good, thick scissors as either way, it will be rather crunchy as you cut the node-ridden same.

The important thing is to only mark your same for cutting when it's DRY. Because same expands when wet and shrinks when dry, marking it while wet will make all your measurements wrong once it shrinks, and your same piece will be too small to use.

Make sure you measure the diameter of your tsuka at BOTH ends, due to the aforementioned taper. Furthermore, it's better to err on the side of caution and cut out a little more than you actually need, than to cut too little and let the poor little stingray die in vain.

Soak your piece of same then wrap it around the tsuka for preliminary fitting. To secure the same onto the tsuka, most people tie tsukamaki around the whole thing, but I found something better laying around the house - reusable ties! To make things go smoother, pre-loop the ties before you begin wrapping.

Make sure the emperor node is on the OMOTE side (the side of the tsuka that faces away from you when you wear the sword, same side as the kurikata). This means the seam formed by the edges of the same piece will be on the URA side (facing you when you wear the sword).

Also, the emperor node doesn't have to be all the way down at the kashira end, but it should be far down enough that it doesn't get in the way of the mekugi or menuki.

This method of wrapping the same around the whole tsuka is called "marugise" . This has the advantage of providing the most strength to your tsuka.

Many katana made outside of Japan and iaito (even the high-end ones!) use the "tanzaku" method, where a wide channel is cut on either side of the tsuka, and panels of same inserted on either side. If you carefully push a part of the tsukamaki aside on your iaito, you'll likely see an example of this.

The latter is cheaper as it uses less same, but it doesn't have the strengthening advantage of the marugise method. However, if the tsuka is well-made, this shouldn't be a problem.

Another good thing about tanzaku besides lower cost is that it makes the most use out of a same, where the smaller pieces would otherwise be discarded.

Once the same is completely dry and won't shrink anymore (give it at least a day), the edges will overlap as expected, since we've cut off a little more than needed.

To make it a better fit, use a ruler and draw a line down the center of the tsuka on the overlapping edge, where the seam should be.

Then, slide the same off the tsuka and cut along the line. If you are able to cut the same dry, this will save you another day of the soak/wrap/dry cycle.

After cutting the same, slide it back on the tsuka, and use the newly cut edge to draw a line on the underlying edge.

Slide the same off, cut the underlying edge along the line, then slide back on again.

This completes round one of preliminary fitting. Although the seam is nicely formed, the same will still be a little loose since it was cut after fitting.

Therefore, slide off and soak the same to begin the next round of fitting.

Once the same has completely dried again, you may need to do some more trimming or fine tuning of the edges with sandpaper.

So you might be wondering why bother with the effort of making the seam seamless when you could just hide the seam along the ha or mune side of the tsuka under the tsukamaki.

Firstly, when you cut with the sword, the ha/mune (sharp/blunt edge of blade) sides of the tsuka take the most stress, so putting the seam along either of those sides would render the same less effective in structurally reinforcing the tsuka. Again, this is not so much an issue if the tsuka is well built if you absolutely don't want to see that seam.

Secondly, to ensure that the emperor node still centers on the omote side, you will have to offset your piece of same when you first cut it out. This means you would need to start with a bigger same - and waste more of it.

If you look at many specimens of nihonto on the internets, you can see a lot of them have the seam on the ura side. This is a sign that the same has been wrapped marugise style.

Unless your tsuka maker is trying to fool you with tanzaku panels to fake the seam.

 

That's it for this week while we wait for that same to dry.  Next week, I'll continue with the tsuka and get it fitted for mekugi.

On to Part 4

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