Rapidly-breaking shinai

[namabiru]

Hiya,
So when I moved from Japan this summer I seamailed 5 new shinai which I had bought from my sensei's shop at a Christmas sale. In the course of 4 months, I've had to prepare 4 of them. This never happened to me in Japan. One shinai would stay good for at least 6 months.

Now, granted, I'm in the god-blessed desert, and it seems that my teammates are also continually having to change shinai, but I really went through those quickly. I'm using, incidentally, a women's 38, which I've always used.

Before I used them even once I disassembled, numbered, sanded slats, and olive oiled, then reassembled. My tsuru tension was the recommended finger and a half to two fingers, which I measured with pointer/flipper offer finger. Yet within two or three practices I'm having to disassemble and change slats.

The way that the slats are breaking is also funny. They aren't merely making cute little splinters on the sides, but instead breaking violently rom the inside.

I've purchased some linseed oil, and may try that in lieu of olive oil.

But what could the breakage be attributed to? After careful thought, I can only think of a few factors.
1. It's just too dry in my temporary unbeloved desert home.
2. Olive oil is somehow reacting badly with the shinai slats, even though other people use it.
3. Is my tsuru perhaps too tight, even though I'm going finger-and-a-half to two fingers? When I test my work by squeezing the slats, they move without seeming hindered yet are not too loose.

Can someone give me any insight? I'd really appreciate it, being a graduate student who doesn't want to always be spending $100 at a time to order shinai from ebogu.

[tgsfg]

Hiya,
So when I moved from Japan this summer I seamailed 5 new shinai which I had bought from my sensei's shop at a Christmas sale. In the course of 4 months, I've had to prepare 4 of them. This never happened to me in Japan. One shinai would stay good for at least 6 months.

Now, granted, I'm in the god-blessed desert, and it seems that my teammates are also continually having to change shinai, but I really went through those quickly. I'm using, incidentally, a women's 38, which I've always used.

Before I used them even once I disassembled, numbered, sanded slats, and olive oiled, then reassembled. My tsuru tension was the recommended finger and a half to two fingers, which I measured with pointer/flipper offer finger. Yet within two or three practices I'm having to disassemble and change slats.

The way that the slats are breaking is also funny. They aren't merely making cute little splinters on the sides, but instead breaking violently rom the inside.

I've purchased some linseed oil, and may try that in lieu of olive oil.

But what could the breakage be attributed to? After careful thought, I can only think of a few factors.
1. It's just too dry in my temporary unbeloved desert home.
2. Olive oil is somehow reacting badly with the shinai slats, even though other people use it.
3. Is my tsuru perhaps too tight, even though I'm going finger-and-a-half to two fingers? When I test my work by squeezing the slats, they move without seeming hindered yet are not too loose.

Can someone give me any insight? I'd really appreciate it, being a graduate student who doesn't want to always be spending $100 at a time to order shinai from ebogu.

I say it's the weather. The Japanese bamboos haven't adapted to the climate?

[Big One]

For the dry weather like desert, why don't you try bio shinai. It is designed to dry climate.

[mark]

It sounds as if your shinai's are drying out. I had similar problems when our shinais used to freeze on the way to practice.

When I prepare a shinai, I use a soaking tube. It is a PCV tube that is caped and can hold a shinai or two. I tend to soak new shaved and sanded shinais in a full tube of oil for a week or so then let the excess oil drip off for a few days in a second tube before wipping it down and assembling it. I tend to use an oil that does not go rancid and will not crystalize if it dryes. Olive oil goes rancid as do some other vegetable oils.
The Japaneese have a relatively specialized oil for this although it is hard to source and is quite expensive. I tend to use linseed, teak, or light sewing machine oil depending on the price an wheter I care if the bamboo changes color or not.

You might also consider making a bazoka. It is capped wide plastic tube with a grate a few inches from the bottom. Fill the bottom with water and store your shinais in it between practice. Other people I know keep their shinai's in the bathroom, or rince them every so often under water. The relative humidity keeps the bamboo flexible.

You could also add oil to inside of your shinai's growth rings on a regular basis.

I don't maintain my shinai's as well as I could and tend to break a stave once every 6 months or so. One of my friends who is somewhat of a zealot breaks a stave once every 6 years or so.

[namabiru]

Thanks for your replies. Yeah, I'm also presuming that they are drying out. A soaking tube is a good idea. I could get shinai oil from Japan, but the amount I'd require would make it sort of cost-prohibitive. But, in all reality, shinai oil is really just a type of linseed oil. If you read the kanji and look them up, that's what you find it is. So linseed oil isn't exactly a radical change.

I recently thought about keeping my shinai in the bathroom, but there are other schools of thought which say you need to keep them in the shinai bag. It may be an interesting experiment, though, to give your shinai a humidity treatment. Go in, turn on the shower and shut the door for a while. If I didn't live in an apartment complex, I'd try to build myself a little shinai greenhouse, since sunlight isn't a problem in Sunny Arizona. But I'm afraid they'd get bothered by idiots, and that would be the end of that.

One of my dojo mates said he used to douse the pieces in a bucket of oil for like a week, but he still had the same problems with breaking. My dojo mates are also going through shinai like crazy. They say it's just the desert.

It's interesting, though, that when I set out my staves and put oil on them, they don't seem to soak up the oil so well. I lay them out on a t-shirt in the living room and fill the grooves with oil, then leave them alone to air dry. The flat is kept at about 72 degrees, pretty constantly. If I had the room, I'd do it in my bathroom, but I barely have enough room to walk in. Perhaps this would help, though, if they dried in a humid area rather than a dry one.

As you can see, I have no idea...

[tgsfg]

The Japaneese have a relatively specialized oil for this although it is hard to source and is quite expensive.

Like these?
http://eguchi.net/T9_oil.jpg

[Kendoka]

Thanks for your replies. Yeah, I'm also presuming that they are drying out. A soaking tube is a good idea. I could get shinai oil from Japan, but the amount I'd require would make it sort of cost-prohibitive. But, in all reality, shinai oil is really just a type of linseed oil. If you read the kanji and look ...degrees, pretty constantly. If I had the room, I'd do it in my bathroom, but I barely have enough room to walk in. Perhaps this would help, though, if they dried in a humid area rather than a dry one.

As you can see, I have no idea...

Many people subsscribe to the idea of adding oil to shinais.

I wet them with water. My logic is (and I know there a sound arguments to use various oils), that the moisture level within the bamboo, reduces the brittleness caused by drying out and that water and bamboo is a better marriage. The climate where I live is very dry, so I add moisture / water by leaving shinails wrapped in a wet towel for a few days, then dry the surface and apply a coat of a waxy polymer, or wax and /or oil. This has worked fine for me for over 10 years. I train 2-3 times a week, use two shinais per training and have to pull apart 3 shinais about twice a year to do some maintenance.

[mark]

Like these?
http://eguchi.net/T9_oil.jpg

I am not sure, I do not read Japaneese:( I do however know people who use that can and swear by it.

You would have to find a source that sells it by the literr, since filling a PCV tube takes a few liters of the stuff.

[Ignatz]

. . .breaking shinai. . .

Are you training with taller people now than you were in Japan? Are you hitting mengane?

[Halcyon]

I recently thought about keeping my shinai in the bathroom, but there are other schools of thought which say you need to keep them in the shinai bag. It may be an interesting experiment, though, to give your shinai a humidity treatment. Go in, turn on the shower and shut the door for a while.
This kind of cycling between humidity and dryness seems to be worse for the shinai in my experience.

My dojo mates are also going through shinai like crazy. They say it's just the desert.
Alas, this may indeed be true. I don't normally recommend carbon shinai, but maybe you should consider getting one for kihon-geiko and save your bamboo shinai for jigeiko.

[namabiru]

Mmm! The towel idea is a good one. I wonder if it would also be a good idea, for ongoing maintenance, to put them in a towel between training sessions. So you go home, you wet an old bath towel, you put your shinai in there, wrap it up, and leave it alone. Then you take them out the morning of training so they're not terribly wet, go off to work, then go to kendo at night. I know that Kendoka presumably just does it when the shinai are being prepared, but I wonder if it could be an ongoing thing. I will try this and let you know. I think, though, I will still oil.

Last night I put my shinai in the bathroom (yes, I know, in case I get attacked during the Grand Poo), to try the humidity thing out.

tgsfg--yes, that's right. Shinai oil.
You can get the can version. However, you can also buy an oil version which is packaged like a bottle of machine oil. The budo shops typically sell the canned package, as Japanese kenchi (in my area, at least) don't have this problem with ongoing shinai maintenance, but if you go to a home store like Home Wide you can get the bottled version. Then you take apart and treat.

Ignatz... you know, I *am* training with taller people now. Drastically taller. I could really darn well be hitting mengane. It makes sense! I never thought about that, but yes, I *can* see how, if I were hitting mengane, my shinai would crack a lot faster. It would also explain the types of cracking I'm getting. Not small, cute, easily sandable spinters, but big violent cracks in the inside of the bamboo. I will ask my dojomates tonight, when I hit men, where I'm hitting. Thank you so much for your thought!

[Neil Gendzwill]

I will ask my dojomates tonight, when I hit men, where I'm hitting.Next time you get a new shinai, check it after the first practice. Look at the leading edge of the side staves. If you see a lot of dents there, you are striking the mengane a lot.

[Charlie]

I have been going through the same thing, namabiru, but we are in the cold Michigan winters, and my house has dry heat. I have become a soaker and just use cheap vegetable oil. But you know what I think really contributes? We have a lot of kohai in my club and when I keiko with them I got at their level. We do a lot of ai-men and when the shinai bang together that, I think, contributes quite a bit to blowing out the staves.

[namabiru]

Next time you get a new shinai, check it after the first practice. Look at the leading edge of the side staves. If you see a lot of dents there, you are striking the mengane a lot.

Good point. I looked at a couple of *newer* shinai, ones that I've used since I got to Arizona, and while they aren't terribly dented up, it does look like there are a few dents in slats I've rotated.

So. That means I have to get my arms out further--I'm somehow holding back.

Will work on that and see what happens, in addition to treating and towel wrapping.

[Alison2805]

Hiya,
So when I moved from Japan this summer I seamailed 5 new shinai which I had bought from my sensei's shop at a Christmas sale. In the course of 4 months, I've had to prepare 4 of them. This never happened to me in Japan. One shinai would stay good for at least 6 months.

Now, granted, I'm in the god-blessed desert, and it seems that my teammates are also continually having to change shinai, but I really went through those quickly. I'm using, incidentally, a women's 38, which I've always used.

Before I used them even once I disassembled, numbered, sanded slats, and olive oiled, then reassembled. My tsuru tension was the recommended finger and a half to two fingers, which I measured with pointer/flipper offer finger. Yet within two or three practices I'm having to disassemble and change slats.

The way that the slats are breaking is also funny. They aren't merely making cute little splinters on the sides, but instead breaking violently rom the inside.

I've purchased some linseed oil, and may try that in lieu of olive oil.

But what could the breakage be attributed to? After careful thought, I can only think of a few factors.
1. It's just too dry in my temporary unbeloved desert home.
2. Olive oil is somehow reacting badly with the shinai slats, even though other people use it.
3. Is my tsuru perhaps too tight, even though I'm going finger-and-a-half to two fingers? When I test my work by squeezing the slats, they move without seeming hindered yet are not too loose.

Can someone give me any insight? I'd really appreciate it, being a graduate student who doesn't want to always be spending $100 at a time to order shinai from ebogu.

Hey, this is exactly what happened to me. I ordered 3 38 shinais from the same place as you and all of them disintergrated in no time - not splinters, but bigass splits down the centre of the slats. I think 38s sit around longer in warehouses because they arent in such demand, or it was just a bad batch or something. I have since ordered more 38s and havent had the problem again.

[namabiru]

Mmm... could have been. But I bought these in Japan, where women's 38s are well in demand. May have been a bad batch too. Can't do anything about it tho...

Okay, an update on the shinai. I used one shinai tonight at practice, and it suffered only very minute little splinters on the business end, which was a huge improvement. I removed the few little splinters with fine sand paper, wiped it down with a round of oil (not soaking, just wiping), and applied more wax to the places I sanded (I'm using a cheap candle my former roommate abandoned).

Now I'm trying the artificial humidity trick. I got a towel also abandoned by her, put it under hot water in the bathtub, rung it out really well, and wrapped my 3 shinai in there, leaving the tsuba up area open. I then wrapped this in another towel and the bundle is sitting vertically in a bucket in my bathroom.

The fact that I only got small splinters means that the wax worked well, or else the linseed oil was better for the shinai than the olive oil. Or both.

We'll see what happens.

[Manuka]

When using the humidity treatment in a warm climate be careful you do not trade one problem for another.

Mould (fungus) on the leather parts.
A slimy tsuka does not help kendo much, and the nakyuki will break.

It might be better to disassemble and only wrap the staves.

[namabiru]

Very true. I didn't mention that I didn't wrap the tsuka up, only the wood. As far as the nakayui, what I could do is untie it and push it up next to the tsuka, or as far as I can, so at least it's not in the towel.

Let me go unwrap them and see how they're faring, roughly 22 hours after being wrapped.

[Manuka]

Have you been able to cannibalize unbroken slats to repair broken shinai ?
Will depend on where the joints fall, but you may be able to rebuild a couple from parts.

You should also have a stock of leather parts from the broken ones also in case a nakayui fails.

[namabiru]

Yes, I most definitely have been rebuilding shinai. This joint has ly recently been like Santa's Elves' Shinai Workshop. Every time I turned around I was removing broken slats and subbing in an unbroken one.

So, yeah, I've got a ziploc with parts. nakayui/tsuru units, tsuka, the sakigomi, the little metal piece which I've forgotten the name of temporarily.

I opened my wet towel up and had a butcher's. What I did was untied the nakayui, moved it up top to the sakigawa, then rewrapped the towel primarily around the monouchi (the business portion of the shinai on top), so that no leather was included. Tomorrow I'll unwrap them and let them dry up a bit before practice.

[Kuma]

I'm wondering why soaking in water would be better than a light oil. I realize that bamboo is rather naturally inclined towards water, but oil down't evaporate quite as easily in a warm climate. Won't they dry out quickly? And oil won't give you trouble with mold if you use a non-vegetable oil. I only dropped $12 bucks on mineral oil to soak my staves, and I'll be able to reuse it for quite some time, I'd imagine.

I know that there is an entire thread devoted to this oiling debate, but I don't recall reading anything in it about water vs. oil.

[namabiru]

I dunno. I'm fairly certain oil is better than water. I would think water would soften the wood too much.

I was just doing the towel thing to simulated a humid environment.

It's not so much a warm environment we're talking about here, because it gets really warm in Japan/SE Asia. What a lot of us are missing here is humidity. And that's what we're all saying is causing the shinai to break quickly.

[Kuma]

Ah, I see. I keep my shinai in my bedroom, where I have a humidifier going all day during the winter. I figure that if it keeps my skin from getting dried out, then it must be good enough for my shinai seeing as how bamboo is a little more resiliant than flesh.

I haven't had any trouble yet, but then I don't think that I've done anything too rough with my shinai yet. I'm sure that'll change on Tuesday, when we start training for the Detroit tournament in six weeks.:nervous:

[namabiru]

I had thought about a humidifier too. Problem is I'm in a shared apartment, and I don't like humidifiers running while I'm sleeping, so I don't have a dedicated area in which to set it up. Our dojo is small, too, so it would be hard to find a corner for all of us to store our shinai.

The bathroom and towel trick may have to suffice for now... :(

[namabiru]

I honestly think the wax and humidity combination are working wonders.

The past two nights I have brought my shinai home, not with nasty destroyed slats but rather with mere hintings of surface splintering, which are bound to happen and easy to clean up with a bit of sandpaper. I've then rewaxed and stored the top half or so in the wet towel, nakayui untied and pushed up to the kensen, out of the towel.

[Kenzan]

I've broken two this last year, as in "surprising explosion on impact."
I make certain to check for splinters as best as I can before each practice, but it still happens.
and I store my Shinai in a Shinai Bag I made from cotton.
I think the issue was from dryness, even though I used Vegetable oil every month or so when breaking it down.
I bought two new ones, and one of them I took apart and soaked with a rag and a liberal coating of WD-40.
It seems to be working well, but I'm not certain about the long-term effects of using it.
Have anyone used this on their Shinai before?

[mark]

I think the issue was from dryness, even though I used Vegetable oil every month or so when breaking it down.
I bought two new ones, and one of them I took apart and soaked with a rag and a liberal coating of WD-40.
It seems to be working well, but I'm not certain about the long-term effects of using it.
Have anyone used this on their Shinai before?

WD-40 is a de-greaser used to break down oil. I would think you want to increase the presence and penetration of oil not break it down!

[Kenzan]

WD-40 is a de-greaser used to break down oil. I would think you want to increase the presence and penetration of oil not break it down!

Ah, but isn't degreasing just one of the many wonders of WD-40?
Hmm, (looking at can now) says here it's a lubricant.
Hmmm...It also has a list of *metals* for which it lubricates.

...Uh...huh.
~Says here it also drives moisture from...boat...wood.


..oh


crap.

:(

[namabiru]

Yeah. Plus I don't imagine you've been too popular with your dojomates due to the invisible smell.

Well, don't fret too much. Perhaps you can disassemble and put some oil on them now. They've lasted for a while.

On the other hand, here's what's funny.

My kohai has two shinai, which she's been alternating use on. She had never taken them apart to oil, she only did oil on the surface. At the dojo, we have a relatively new shinai which had never been taken apart for treatment. Yet they seem to last for 3 eons, without nary a splinter. Oddly enough, I wonder if taking them apart to oil, then, is actually counterproductive. *shrug*

[Kuma]

I was under the impression that before use, you should at least take the shinai apart and sand down the staves on the interior to remove splinters and such. Do you mean that they haven't done that with the shinai?

I don't really see how oiling would be detrimental to the strength of a shinai or cause it to break more easily. Live, moist bamboo doesn't snap or splinter, just bend. And oiling is the closest to replicating the state of moistened wood, as far as I know (which isn't terribly far, mind you). I just can't imagine what about oiling could possibly be counterproductive.

[namabiru]

Yeah, that's right. In fact, we've done the traditional "please take the red threads off your shinai before we begin practice" public safety message, as they're brought to the dojo literally brand new.

I, too, was under the "before use, please sand" impression as well.

However, I don't sand the interior. I sand the sides, where that line exists. Then, just recently, thanks to a suggestion I got on here, I started putting wax on the edges.

Yet it's ironic. My new shinai are breaking in no time flat, while the shinai of my kohai are lasting.

The only other explanation I can think of is severity of use. A newcomer to kendo isn't doing the same things to a shinai as a person in full keiko, or perhaps not hitting with as much force at one time. Not to sound derisive, you understand, but just trying to understand.

Huh. Any scientists in the house who could help with an explanation, or more experience kenshi?

[bobdonny]

your hitting too hard...........................................

[namabiru]

Probably. I didn't think my strikes were that hard tho... after all, I'm just a wee lass...