An idea for mekugi from a Western-style smith...

[Al Massey]

Now, I've made very few Japanese swords. But I do love them sincerely- my first "real" sword I was able to buy, over 30 years ago, was an antique katana. She's still with me.
I got into bladesmithing by and by, and it often seemed to me that the real weak point of the Japanese sword was the method of attaching the grip. Inwardly, I've always been peeved at that single little chunk of bamboo being a real potential failure point.
Metal pegs are apparently a real no-no- for reasons of wear and tear on the nakago or the grip, or dissimiliar metal corrosion.
But has anyone thought of the possibilities of a laminate-construction peg?
Here's the idea- peg material, i.e., bamboo, or other suitable fibrous material, with a soft steel reinforcing rod running through it glued into the material. You would have no metal-metal contact in the nakago of the sort that irks collectors so, nor metal-soft wood contact with the mekugi-ana. Yet it seems to me that this method of construction would give you a peg that is several times stronger than simple bamboo and make practice with single-mekugi swords much safer.
Forgive me if my idea has already been tried and failed, but it's one I had to air. I was considering doing some tests on bamboo rods reinforced this way. I'm nuts about testing theories- I'm the guy who intentionally broke and reforged a sword (of my own making, not an antique!) to see if it was workable.

[Dave Drawdy]

sound good, worth a try. have you tried delrin? I know of one polisher/mounter that uses it as an improvement on bamboo.

VR,
Dave

[Jeff Ellis]

sound good, worth a try. have you tried delrin? I know of one polisher/mounter that uses it as an improvement on bamboo.

VR,
Dave

mmm delriny goodness...

It's also called acetal. I've worked in a few machine shops and when the word Delrin comes up, it causes this weird smell memory of a vinegary plastic.

It's a very good substitute, it is less dense than steel, but it is quite strong.

I do wonder, though, how often do you hear of mekugi breaking? How often did it happen?

The only real reason I can think of for them not using steel is that if the mekugi were to rust to the nakago, you wouldn't be able to get them out in case you needed to replace the tsuka. They didn't have much other choice, given the non existence of synthetic materials, however I have heard of copper mekugi.

Other than that, I would suspect that the bamboo is just fine for what it does, as long as it's taken care of and replaced as needed. I've always been under the impression that as long as the tsuka is carved right, all the mekugi did was drive the nakago home and kinda just.. stayed there with barely any force on it, more like a drift pin that you would be using to line something up, and then leave it in place.

[Hrvoje Samija]

Ah... Well, if the mekugi is there, as Jeff pointed out, just to help center the nakago, and bares little or no stress, than bamboo is more than OK...

But, if there is stress on the mekugi, and it has a steel core, while tsuka will probably be OK, the nakago will 'wear out' the bamboo skin, and it will come in contact with the core made of steel... So, there we have the steel on steel, and if the object was to avoid that, it fails...

Just my 10 lipas worth...

[Jeffrey Ching]

As Jeff already stated the strength of the mekugi is the least of your concern with thinking about safety. A properly carved tsuka is the key in making a wieldable sword. That said, the bamboo used for mekugi is extremely though. Copper would take less force to bend than to break a mekugi.

Cool idea though. However when thinking about functionality it would be best to go with polymer or glassfibre mekugi.

ps. two pins puts extra force on the wood of the tsuka (the area between the two pins). A proper handle with 1 mekugi is a lot safer.

[Al Massey]

Ah... Well, if the mekugi is there, as Jeff pointed out, just to help center the nakago, and bares little or no stress, than bamboo is more than OK...

But, if there is stress on the mekugi, and it has a steel core, while tsuka will probably be OK, the nakago will 'wear out' the bamboo skin, and it will come in contact with the core made of steel... So, there we have the steel on steel, and if the object was to avoid that, it fails...

Just my 10 lipas worth...

...is to make a near-unbreakable mekugi. But the steel core, if you will, would also act as a wear indicator in much the same way as wear indicators on many other items, allowing you to notice at once the mekugi is badly worn during disassembly during cleaning. The reinforcement rod could be quite thin, only 3/32"- about, say, 2mm- and still give considerable reinforcement.

[Hrvoje Samija]

Well, when viewed like that, the tsuka regularly taken off and the mekugi inspected, or just taking the mekugi out to check it's state, it could work OK...

But, if that is done as it should be, the bamboo mekugi will show signs of wear just as well and on time...

I was thinking more about the people that tend to leave the tsuka on for long periods, only checking if the mekugi is still there... And added security of a steel reinforcement would probably cause them to take the mekugi out of the tsuka even less frequently...

But, as an added safety, to prevent sudden breakage of the mekugi and the blade flying out, might work OK, if treated just like a regular bamboo mekugi, and frequently inspected...

Although, as I understand it, the good quality bamboo was chosen for the mekugi because it is full of very strong fibers, and if it brakes, the fibers will still keep the blade in check for quite some time... Something the steel reinforcement will not do.. Once it snaps, it snaps...

[Jonathan Frances]

If I'm understanding the description here, then if the "skin" wore down to that extent, the mekugi would be fitting loosely, so metal contact with the nakago seems fairly unlikely.

A metallic core could provide a more obvious visual clue too, once you see metal you know it's time to replace the thing.

I am not really seeing a downside. It might be over-building things a bit, and leaning towards the Monster cable mentality, but is that really a problem? Over-built is better than under built.

[M. Steinbroner]

I have used carbon fiber rod (available from McMaster-Carr) with good results...very strong, flexible, and repeatable.

I have also used Delrin, which is also available from McMaster. Also a decent choice. My experience leads to the carbon fiber rod being a stronger, more resilient choice.

Matt

[John Coris]

I think that a laminated mekugi, would be a waste of labour and resources, as it would be marginaly more useful than a simple bamboo. The outer bamboo would age like any bamboo wood and if propely made the mekugi do not suffer any considerable stress in order to take advantage of the extra hardness. However, I 'd like to see in in action and if the psycholoigcala advantage it might offer would improve the wielder's cutting...

[Anders Backlund]

The way I've been told, the reason metal mekugi is a bad idea is because it puts more stress on the tsuka. A metal mekugi is part of the nakago, whereas a bamboo mekugi is part of the tsuka. Don't know if that theory holds water, though.

That said, I'm sure there's some way of making a synthetic alternative if you just put your mind to it. Still, I can't remember ever hearing about mekugi breakage being an issue in the first place so the question is if it's actually worth the trouble.

[jim rousch]

A well fitted Mekugi stays in place due to the action of friction. You simply cannot improve on nature. Also there are traditional mekugi that are made of metal and are called Neji Menuki. As far as I know they were used on a particular type of Aikuchi Tanto.
Jim

[k.moralee]

A well fitted Mekugi stays in place due to the action of friction. You simply cannot improve on nature. Also there are traditional mekugi that are made of metal and are called Neji Menuki. As far as I know they were used on a particular type of Aikuchi Tanto.
Jim

I'm with Jim on this one. The problem I see with inserting metal pins into a wooden/bamboo mekugi is you are going to lose any of the benefits wood will give. When the force of using a sword is exerted the mekugi isn't going to have the give in it that it would if it was made of only bamboo, it will hit a resistance and quite possibly wear from the inside out causing failure.

[Jeff Ellis]

I'm with Jim on this one. The problem I see with inserting metal pins into a wooden/bamboo mekugi is you are going to lose any of the benefits wood will give. When the force of using a sword is exerted the mekugi isn't going to have the give in it that it would if it was made of only bamboo, it will hit a resistance and quite possibly wear from the inside out causing failure.

I thought the benefit of Bamboo was that it had strands of material that were different lengths resulting in an uneven, interlocking break if it actually did break?

If your mekugi is getting that much stress on it, you really need a new tsuka.

[k.moralee]

I thought the benefit of Bamboo was that it had strands of material that were different lengths resulting in an uneven, interlocking break if it actually did break?

If your mekugi is getting that much stress on it, you really need a new tsuka.

You're probably right, I should've said bamboo/wood as people use other medium for mekugi. The point I was getting at gets back to a discussion about using metal pins as mekugi and the possible issue that could have i.e possibly stretching out the mekugi-ana, snapping under stress etc.

Correct me if I'm wrong but does not the mekugi take some amount of stress during its lifetime? Would inserting an object that is harder than the mekugi itself not cause an undue amount of wear?

I hear what you are saying about excessive wear if the tsuka is in need of replacing but I think inserting metal pins into bamboo/wood/buffalo horn is just going to wear out the mekugi that bit faster.

[Keith Larman]

Hey, guys, took a long weekend with the family. Hadn't had one of those in a very long time. Just now getting to 4 days of e-mails... Wow, the world just keeps on going even when I go away... Funny how that works.

Anyway... On mekugi. I've forgotten how many rigs I've made now over the years. Been quite a few. I've experimented with a lot of stuff. I remember early on coming up with an ornate system of reinforcements, etc. myself. But... After all this time... I'm back to a simple thing.

It ain't metal. Metal is is really hard. It tends to deform wood. Permanently. And it likes to expand and contract under temps. And given the nakago of antique swords are often dead soft pounding a harder pin into place can deform the mekugi-ana. Not cool.

I use 1 pin for katana. I prefer to use my delrin pins, but I will use seasoned susudake (a type of bamboo) as well. I will do a second pin if requested as some groups do prefer/require a second mekugi. That's cool with me.

Why use delrin? Because it's tough, durable, cheap, and you can easily machine it. And then since it can be precisely machined I can use my #5 (or was it #4?) tapered reamer to make an extremely precise taper to the ana on the tsuka. Why is this nice? It means the pin has maximal contact with the ana and pushes into place slightly crushing into the wood fiber, locking into place. Done correctly if the tsuka develops a little play I can take my nifty reamer, expand the ana on the tsuka (with the tsuka off the sword), then take another pin, push it in until tight, and it will pull the sword deeper into the tsuka (assuming the tsuka core was carved correctly -- most production swords aren't amenable to this -- Bugei's are by request). And I can have a buddy make me a handful of extra long pins periodically in exchange for cash or beer. Pop in a new, long pin, mark the exit and entry points on the pin, a few swipes with my jeweler's saw, and voila, new pin.

So easily maintained. Easily adjusted. Precision fit. Tough material. What's not to love?

This gets to the real issue. One of quality and care. The better the tsuka shitaji is carved the better it fits. The better it fits the tighter it will be. The more intelligently (or maybe better properly trained in the details) the carver is the more flexible the tsuka will be with adjustment keeping the tsuka tighter, longer. Each part is just one small part of a much bigger whole. And like the proverbial chain, the weakest link is what you worry about.

The weak link here depends on context. Many production swords have tsuka that are so poorly carved that I don't care what you use as a mekugi you're basically putting bumpers on a jumbo-jet. When that sucker nosedives into the ground the bumpers aren't exactly going to make much difference, neh? If the handle comes apart in your hand the pin probably ain't making much difference.

Add to this that I've never seen a pin broken in a properly made and maintained katana. I've seen some terrible pins, of course. Made from cheapo chopsticks (what are those -- balsa?), random mystery woods, I even saw one that had what looked like rolled up duct tape shoved in (which actually was really tough to get out). This isn't brain surgery.

The bigger problem is the guy who takes the sword apart but forgets to replace the mekugi. One or two likely won't matter in that scenario. So if the guy forgets to replace the mekugi, it really won't matter what they were made of...

Of course you could go the way of a defunct group that put in three. At angles too. Wow. Zoweee. If one is good, two is better. Three must be great. Shoulda done 4... Silly. All marketing fluff. Sell the sizzle instead of the steak.

The fact is that the pin should pull the blade into place where it is tightly pressed into the channel of the tsuka. Think of it like a a type of ratcheting thing where as you pull the cord the device locks down preventing it from releasing. So it should be tightly in place when the pin goes in. And the pin should just keep it there or even pull it in a hair more. Now everything is one piece.

Okay, given that, how does 2 pins help? They really don't. One is probably doing the heavy lifting while the other one is likely just a hair off. Hopefully they did everything else right and don't have the scenario where one pin is pushing forward while the other back. That's a bummer... And stupid. But I've seen that too.

The bottom line for me is that as the sword gets more cheaply made, well, maybe the pin selection becomes more important. But you have to really ask yourself a larger question -- if I'm having to worry about the pins being super strong should I swing it at all?

Now I like the acetal stuff. I'll use delrin, micarta, etc. for various parts. I tend to use the stuff for koiguchi and kojiri simply because I can buy large strips of the stuff at the exact thickness I want. Cut off a piece the size I want and voila. Normally the horn gets painted/lacquered over anyway. So... The stuff doesn't have a grain so it doesn't tend to crack like horn. And it is durable, relatively moisture and temp stable, etc.

All that said... Horn for parts and susudake for mekugi work just fine assuming it is done correctly. And that part after the word "assuming" is really the critical part. There really is no reason to get any more high tech than that.

So I look at the issue as a sort of solution to a problem that shouldn't exist. If everything else is done reasonably well the mekugi takes virtually no stress and is really just a pin holding things flush. Everything stays really tight a whole lot longer and the world turns just as it should.

Just make sure it's there before you swing the thing. Kinda like good gun safety. Kinda like looking behind you before you back up your car. Kinda like putting on your seatbelt before you go roaring off.

Common sense.

[Keith Larman]

I'll add that this question often reminds me of the great debates on sword oils. People look to all sorts of fancy gun oils, fancy this or that. Light mineral oil is more than good enough 99.9% of the time. Just do it every month or two when it's not in use. Clean it when it is then oil it right away otherwise. Cheap, easy, simple, readily available. Want it to smell a bit more traditional? Buy the choji scented stuff. It's just light mineral oil with added clove for scent. An 8 oz bottle should last a long time for the average sword unless it is being used a lot.

The fancier stuff actually carries more risks to fragile lacquer work, patina on antique parts, etc. than the plain oil. So I see zero reason to get fancy.

Sewing machine oil works too. Same stuff. Exactly the same stuff.

I.e., it ain't rocket science. And it is easy to overthink it.

That said... I experimented with a bunch of stuff myself. And over the years... Yeah, I've got a 5 gallon jug of light mineral oil I bought somewhere years ago. With a dispenser doohicky. When I need more in my jar I keep on the table I put a squirt into the bottle. I think it is about an inch from the top of the jug and I gave Howard Clark a large bottle of the stuff one day when he was driving through town on a family vacation. I even dumped a little clove oil in the large jug so it smells right too...

As I said, in the bigger picture it's really not a big deal.

[k.moralee]

That's that one answered then

Just a quick question Keith,

Would it be a bad idea to use horn mekugi on an iaito? I was going to replace the ones I have in there at the minute and have just bought 2 buffalo rods for the job. The tsuka is really tight so there is no play at the present time as the sword is new but it is going to be my permanent sword of choice for the foreseeable future so it will see a lot of use.

Cheers

[Keith Larman]

Horn is not a good idea. Great as a decoration. But horn can dry out, crack and is often a bit fragile. One of the reasons for me using black delrin/acetal/micarta is that you can polish the faces reasonably nicely and make them look like horn (which is a traditional look, just a heck of a lot safer)

[k.moralee]

Damn, I was looking forwards to re-mekugi-ing my iaito as well. I'll use one in my wakizashi that is really just display. Cheers for the heads up Keith

[Jeff Ellis]

I remember a material I worked in a machine shop once that had a strange tortoise shell look to it when machined. I want to say it was called "Torlon," however I am not finding any google images of Torlon looking like what I remember.

If this is the right material, and it's just a variation, it's supposedly similar, if not better, than Delrin under high stress. I'm looking at what I can find on it, but it might be useful for you to look into it?