Saya Fit

[a_d_sanders]

Just how loose should a saya be before it is considered too loose?

A friend has an iaito that is devilishley hard to extract from its saya. (Good for building up a powerful left thumb.)

I've recently acquired a new iaito and am now paranoid that it is too loose. A little wiggle when it is upside down will release sword from saya. This seems very loose to me, but I am not sure.

Has anyone got any thoughts on this matter?

Thanks,

Andy Sanders

[louroberto]

Hello, my first iaito was very loose also. It taught me to keep my thumb at 1:00 all the time. I now have a new iaito with a very tight fit. After about 1-2 months it seems to be freeing up a bit. Just keep you thumb in the right place. You do not want to loose your sword in the middle of class. Good luck!

[hyaku]

It should not be loose. You should be able to turn the weapon tsuka down and expect it to hold. Cut a wedge shaped small sliver of wood and try it for fit then glue it inside. Even if the habaki still shows a bit, it will seat in with use.

[cuchulain]

I recently bought a new iaito in Japan, and it came with rather a loose fit. I have a friend who trains in Shinto Ryu in Tokyo and he told me Otake Sensei advised him to use a small piece of Japanese paper and just use wood glue to insert it inside the mouth of the saya. It snugs up the fit right the way around the habaki and works a dream - and as Colin points out above - you should be able to turn it upside down and have it stay where you left it.

[pgsmith]

Using wood glue will work if you're very careful. The problem being that wood glue dries very hard, and habaki are intentionally fairly soft. If you have wood glue exposed, it can fairly quickly wear scratches in your habaki.

My favorite way of tightening the fit is to get some birch veneer from the local Home Depot. It comes in rolls to use on cabinet facing. It has heat sensitive glue backing on it. You cut a small piece to fit into the ha side of the koiguchi, heat a small screwdriver with a lighter, apply it to the cut piece for a couple of minutes, and you're done. It's easy to apply, quickly done, and the glue backing is soft and won't contribute to inadvertent damage to the habaki.

[nicojo]

In a pinch, scotch tape wrapped around the habaki a few times will do, though it will eventually squish flat and you will still have the problem. However, I did this for a dojo-mate just before our demo at the matsuri and it works fine for about a month.

When you take off the tape, it will leave a bit of adhesive on the habaki so be sure to clean it off before sheathing. The other fixes mentioned here are more permanent and better, but I thought I'd share mine for those times a quick fix is needed.

I have a friend who trains in Shinto Ryu in Tokyo and he told me Otake Sensei advised him...

Hmm, I don't think Otake sensei teaches SMR.

[cuchulain]

Obviously it's (Tenshin Shoden Katori) Shinto Ryu, but I sort of presumed most people here would know who I meant. Anyway, some good advice all round.

[kdlarman]

Fit is a funny thing. I frequently get swords from Japan and when they arrive they're fine. After about a week the saya are *way* too tight. Moisture variations I assume.

When I mount a sword I'll make sure it is *very* tight when it leaves. And by tight I mean ha and mune side only. The ji surfaces should be kinda in contact but not tight by any stretch of the imagination. Unless you like a split saya...

Anyway, if the saya is going someplace vastly more moist the saya will invariably loosen a bit. So it all depends on where it was made, the weather when it was made, where it's going, etc.

My suggestion to most with a new sword is to simply wait a few weeks for everything to stabilize. It will continue to change over time so you need to let the saya "aclimate" to where you are. Once it appears to be where it wants to be, then do what Paul up above described. Works great, doesn't put in too much glue, and doesn't require a lot of effort or skill to do it well. Just a little time and the end result is very good.

Put the first pieces on the ha side. If you still need more, you can stack one or two pieces there on the ha side. If it is *still* loose, consider putting one on the mune but do it precisely and carefully to match the iori of the mune. Never shim the sides. Never.

Basically the sword should stay in the saya when inverted. But you shouldn't need a crow bar to get it out either.

Production swords (and less than well done custom stuff for that matter) often have habaki with too sharp or not enough taper. When the taper is too much the blade tends to go from very tight to completely loose. The blade should gently settle into a tight fit. It takes some pressure to release it but it releases smoothly. Too much angle and they "pop" in and out. Not enough and they're just kinda sluggish no matter what you do. So if your habaki is screwy there's not much you can do except to adjust the habaki and then the koiguchi of the saya to get a better fit.

[nicojo]

CuChulain:

Obviously it's (Tenshin Shoden Katori) Shinto Ryu, but I sort of presumed most people here would know who I meant. Anyway, some good advice all round.

Hey it wasn't a big deal for me, I just thought another new person might see the thread later and get the wrong idea. The people who train in it under Relnick sensei (and Otake sensei) that I know say Katori Shinto ryu most often, which makes sense because there are other ryu like Shinto Muso ryu and Shinto ryu (there is a group in Seattle but it isn't related to KSR), which are different altogether, as you know.

[hyaku]

I'm lost a bit here. There is no specific way related to a ryu is there? Does the ryu you belong to have some influence in this?

A sliver of leather also works. It just depends on how loose it is. I suppose like furniture it depends on what wood is used to make the saya. One of mine dried out to the extent that it started to split. I am guessing they did not use well seasoned wood in making it.

Personally I have not used Iaito for many years. But what I have experienced between buying iaito and shinken you get what you pay for. I would check out these things before I bought anything.

I am helping someone buy an Iaito tomorrow. If I mention that the saya is too loose at the shop I go too I would probably get an even better discount.

[nicojo]

Hyakutake sensei,

I don't know if you are addressing me, but no, this doesn't concern me with any ryu. I made my comment because I thought a future reader new to these arts and teachers who is unfamiliar with our shorthand abbreviations and name-dropping might confuse KSR with any of the other ryu. The Shinto ryu that Chris Moses studies, for example, or the Shinto Muso ryu. A small thing and this thread drift wasn't my intention. Sorry to have mishandled it.

The small trick with the tape was in fact taught to me by an instructor in the ryu I study, but I'm sure others know about it. Again, it is a stop-gap measure and I would not recommend it with a shinken since it is so temporary.

---
Lol, I'm better off not posting. I'll find some tape...

[nicojo]

Thanks for the PM Hyaku.

KDLarman:

Put the first pieces on the ha side. If you still need more, you can stack one or two pieces there on the ha side. If it is *still* loose, consider putting one on the mune but do it precisely and carefully to match the iori of the mune. Never shim the sides. Never.

Nice to read your posts Mr Larman. I'm guessing some reasons for this order is that shimming the sides will cause the saya to splay at the koiguchi, or a material can scratch the side of the blade? Or is there another reason?

TIA.

[kdlarman]

Two reasons. The saya is thinnest (generally) at the ha and up on top of the mune. So less material means those are the most likely point for the saya to crack. And putting shims on the side simply adds pressure to crack the wood in those locations. Secondly it depends on the type of glue used. Modern glues are stronger than the wood (again, generally) but if you're dealing with an older saya or the sayashi used traditional rice glue it is more likely to put pressure on the glue joint and cause it to split.

When you carve a saya it is the "ramping" of the habaki on the ha and mune which generates a tight fit. The sides should be close to ensure a relatively air tight fit, but usually we don't want it "tight" there. Basically tightness should come from the subtle angle of the habaki on the ha and mune.

I've broken down a lot of antique (and a few modern) saya over the years. Mostly to see how a "retired" saya was built, carved, etc. They are relatively easy to split by pulling them apart breaking either the glue joint on an antique or simply leveraging them open breaking along the ha and mune. The ji sides are dramatically thicker wood usually and much tougher.

[a_d_sanders]

Thanks for all the replies.

In particular, Keith Larman's description of saya weak points is most helpful.

Cheers,

Andy Sanders

[pgsmith]

If I mention that the saya is too loose at the shop I go too I would probably get an even better discount.

One of the many advantages of being able to wander over to the local sword shop eh!