If you practice kendo, you may have had the experience of your instructor telling you to "check your bamboo sword" during practice.

However, in reality, surprisingly few swordsmen have a systematic understanding of the correct way to care for their shinai and the safe procedures for inspecting damaged shinai .
Many people may say, "I just polish it for no particular reason" or "I'm just filing away any splinter marks." I often hear stories of parents with children who practice kendo who are at a loss as to what to do.

In this article, we will clearly explain the basic maintenance methods for bamboo swords that everyone from beginners to advanced players should know.
Furthermore, we will provide detailed expert advice on how to break in your bamboo sword immediately after purchase , as well as tips on how to store and care for it to make it last longer .

What is a bamboo sword?

The bamboo sword used in kendo is not just a tool for practice.
The All Japan Kendo Federation teaches that "Kendo is a path to self-creation, aiming for the unity of mind, spirit, and power through the use of the bamboo sword."

He also states, "The bamboo sword is a sword that is pointed at the opponent, but it is also a sword that is pointed at oneself. The key point of instruction is to achieve unity between the bamboo sword and the mind and body through this training."
In other words, the bamboo sword is a symbolic object for honing one's mind and technique , and represents the spirit of kendo itself.

Modern swordsmen also regard the shinai as sacred and must be grateful for the opportunity to hold it and handle it accordingly. For this reason, they must not straddle the shinai or kick it with their feet.

Why inspect your Shinai?

The reason for inspecting the shinai is that it is extremely dangerous to continue practicing with a damaged shinai.

There is a risk that splinters from the bamboo will get into the opponent's eyes, and the broken bamboo may pierce parts of the body that are not covered by the armor. Not only that, if the tip of the bamboo is loose, it could lead to the dreadful situation of the bamboo flying out.

It is a basic principle for kendo practitioners to regularly check their shinai for any abnormalities during practice, and to take good care of them after practice, and it is also a sign of respect so as not to injure their opponent.

Related article: How to inspect and adjust your Shinai! https://bushizo.com/media/202007/4279 /

How to care for your bamboo sword

If you find any damage while inspecting your shinai, immediately stop using it and use a replacement. After practice, be sure to take care of your shinai. Here we will explain how to inspect each part of your shinai and how to take care of them if they are damaged. *All you need for maintenance is a shinai sharpener and sandpaper. It is also effective to use shinai oil or other oils to prevent the bamboo from cracking.

Sandpaper-type bamboo sword sharpener "Takema-kun"

Bamboo sword carving master

·bamboo

The bamboo is the part of the shinai that receives the most impact from a strike.
Among these areas, the area known as "monouchi" is subject to repeated strikes during training, making it prone to fraying and cracking.

If left unattended, there is a risk that fragments may fly at your opponent or get stuck in gaps in your armor, so be sure to inspect them before and after practice.

How to check for splinters and cracks in your bamboo sword and how to repair them

The key points to check are:

1. Are there any splinters in the striking part?

2. Are there any cracks or breaks?

3. If it is a carbon shinai, are the fibers exposed?

By checking these things on a daily basis, you can maintain safety and extend the life of your shinai.

What to do if you find a hangnail

If the splinters are small, you can simply remove them using a shinai sharpener or sandpaper without disassembling the shinai.
On the other hand, if you suspect large splinters or invisible cracks, we recommend disassembling the shinai and checking the inside.

The key to using a bamboo sword sharpener is to place the blade at an angle close to a right angle to the bamboo and keep the cutting direction constant.
Once you have finished carving, smooth it out with sandpaper, and finally, lightly wipe the entire surface with a cloth moistened with a small amount of shinai oil to prevent it from drying out and making it less likely to break.

Tips for rearranging your bamboo sword

When rearranging a shinai, the shinai is first disassembled and the "chigiri" (bonds) that connect the four bamboos are removed.
If the grooves in the new bamboo do not fit the kiri, a new groove is made using a saw or similar tool.

If the groove is too tight, the contraction will not occur, and if it is too loose, it will not be able to be firmly fixed.
The trick is to not cut too deep right away, but to adjust little by little while watching the progress.

Rotating the striking side is counterproductive

Some people think that if they rotate the bamboo, the shinai will last longer, but this has the opposite effect.
Applying force in the opposite direction to the normal force puts undue strain on the bamboo fibers, making them more susceptible to breakage.

・Snow leather

Check the tip leather for holes or signs of tearing. This will prevent the risk of the bamboo sprouting. If there are holes or the tip leather is about to wear out, replace it immediately with a new one. The thickness of the tip leather is regulated by Article 3 of the Kendo Match and Refereeing Rules and Article 2 (1.2) of the Bylaws established by the All Japan Kendo Federation, so be sure to use a size that is appropriate for you, taking into consideration factors such as your age.

・Medium knot

Check that the knot is not loose and is not about to break. The role of the knot is to prevent the four bamboo stalks from coming apart. If the knot is loose, the leather tip will also come off easily, so be careful. If it is loose, tighten it firmly. Also, if you were unable to tie it completely at the end and there is excess end, use scissors to cut it to the appropriate length.

·string

The string is what prevents the shinai from coming apart when it bends. If it is loose, the tip leather may come off when you strike, so make sure it is taut. If it is loose, tighten it again. The handle leather and the string itself will stretch as you use it, so make sure to tighten them regularly.

・Patterned leather

If the handle leather is loose, the dexterity of your hand will not be transmitted to the shinai properly. To improve your performance, use handle leather that matches your shinai. If it becomes loose with use, replace it with a new one. If you want to reuse it, pour a little boiling water over it to shrink the leather. It will become a little slippery when it dries, so squeeze the leather to make it more flexible.

How to care for your watch after purchase

It is important to take care of your bamboo sword when it is damaged, but you can also keep a newly purchased bamboo sword in good condition by taking care of it in advance.

・Ventilation and humidity

After purchasing a shinai, store it in a place with low humidity and good ventilation. It is also best to store it in a place that is room temperature and does not easily get hot. Although it takes more effort, it is more effective to remove any accessories when storing it. This is because the leather used in the accessories contains chemicals such as formalin, and leaving it on can accelerate deterioration.

・Bamboo sword oil

Soaking the bamboo in oil and leaving it for a few days is also an effective way to maintain the strength and longevity of your shinai. To do this, soak some oil-soaked tissue or cotton wool in the bamboo and insert it into the joint where one piece of bamboo has been removed, as this is because bamboo only absorbs oil from the joints. After this, reassemble the shinai and secure it with string. It takes about one to two months for the oil to soak in.

There is a special oil for bamboo swords, but if you use something else, it is best to use one that is made from the same plant material as bamboo.

Some people use wax instead of oil, but I don't recommend it. This is because wax can be applied unevenly and may get on your opponent's armor during practice. Once wax gets on your body, it's difficult to remove. Furthermore, when it gets cold, the wax may peel off and stain the floor.

summary

We have introduced various methods for caring for your shinai. If you have read this far, you may be thinking that there are many steps involved and that it is a hassle.

However, it is not enough to simply pursue strength; only when you take care of your bamboo sword to ensure safety and are considerate of your opponent can you call yourself a kendo practitioner who "respects courtesy even in the arena of competition."

Also, by taking care of your shinai, you will develop an attachment to it, and this will bring about a change in your heart. By always taking care of your shinai and practicing diligently, you will also improve your kendo skills.