This section of the series begins to cover some of the simpler first aid tips to temporarily repair some of the more common problems associated with normal wear and tear on a sword through iai training. Keep in mind, however, that first aid repairs are just that, first aid. They will keep a katana in working order until proper repairs can be made. In most cases, especially when dealing with a shinken (real katana) it's a good idea to seek out professional advice before attempting anything permanent.
Tip #1 Keep a Well Stocked Repair Kit
As I've had to make various repairs to my katana through the years, my basic repair kit has gotten bigger and bigger. Some good things to keep on hand include:
Basic Kit (This goes with me wherever I take my katana)
NOTE: Unless you have easy access to the ingredients to make sokui (see tip #8), it's also a good idea to keep a little acid-free, non-corrosive wood glue on hand.
Home Kit (This is for more involved repairs that I can't make on the
road or in the dojo.)
WARNING: If you are allergic to poison ivy, poison oak, or poison sumac, don't risk using real liquid lacquer. Don't even keep it around the house, because just the fumes can cause severe skin blistering and rashes in people who are sensitive to urushiol.
Tip #2 Mekugi (Retaining Pegs)
One of the stories that nearly every student of iai hears at some point in their training, is of a terrible accident that occurs because of old or defective mekugi. Versions vary, but the basic plot is usually the same: a retaining peg fails, a blade flies free, someone is impaled. Whether or not these stories are true, they still serve as good illustrations of what could happen if mekugi are not routinely checked for any signs of damage or wear. After all, that one little piece of bamboo is all that is keeping a two foot razor in its handle.
A good habit to get into is of checking the mekugi every time the blade is cleaned. When checking make sure that:
Where to Get Mekugi
Rule of Thumb: If it looks like a piece of a cheap chopstick, don't use it.
Making Your Own Mekugi
One bamboo will make literally handfuls of mekugi in this way. I'll have to admit, I'm a little spoiled. Having used handmade pegs for years and seen how strong and durable they are, I would be very reluctant (not to mention wary) of ever using a mass produced one again.
Tip #3 Sokui (Rice Glue)
If you are using a shinken (a real katana), it is a good idea to seek professional help before attempting any repairs. Even the glue used to fix minor problems with the saya or tsuka, can adversely affect the metal of a real sword. Therefore, care should always be taken when selecting materials. Many glues that are available on the market which are used for woodworking, contain chemicals which give off fumes which can damage the metal of real katana. Iaito are not quite as susceptible, but if you would rather not take the risk, a simple, traditional glue called sokui is easy to make.
How to Make Sokui
Advantages of Using Sokui for Various Repairs
To make sokui even stronger, a few drops of natural lacquer can be added while mashing the rice.
WARNING: Natural lacquer can cause allergic reactions. It contains a compound called urushiol which is the same toxin found in poison ivy, poison oak, and poison sumac. Four out of five people are allergic to urushiol, and reactions usually involve severe skin blistering within one to twelve hours of contact. In natural lacquer, this toxin is active until the lacquer has completely hardened. Even when the lacquer appears dry, if it has not completely hardened, it can still be giving off vapors which can penetrate the pores of the skin causing reactions. Therefore, adding liquid lacquer to sokui to harden it can be dangerous for some people.
If you do get a mild case of lacquer poisoning, treat it like you would a poison ivy rash.
If the rash continues for more than a week, or if you start getting headaches or a fever, consult a physician. If a severe reaction occurs, don't wait, go to the doctor immediately.
How to Use Sokui
Tip #4 Fixing Worn Koiguchi
In Part I: Tip #3, I outlined some ways to keep a koiguchi in good working order. However, despite a person's best efforts to protect it, a koiguchi will eventually become worn from repeated drawing and sheathing. When this happens, there are numerous ways of fixing the problem.
Using sokui, glue a thin piece of acid-free paper to the inside of the koiguchi. This paper should be of the necessary thickness to insure a snug fit between the koiguchi and the habaki. The paper will eventually wear down and have to be replaced.
Cut a small rectangular piece of suede or soft leather about 1" (2.5 cm) long and about 1/4" (6 mm) wide. Use a sliver of wood (such as a toothpick) to spread a bead of sokui on the inside of the koiguchi where the mune rests. Apply the piece of leather and hold it firmly in place until dry. Please note that the leather must be thin or it may interfere with proper sheathing. As with paper, leather too will have to be replaced on occasion because it will come out with time and training.
Saya are traditionally made from ho no ki (Magnolia obovata) because it is soft and will not scratch the blade. It is also easy to work because it has a regular grain and when properly dried, retains almost no sap. (Sap can have detrimental effects on the metal of sword blades.) With all this in mind, it makes since that the best way to repair a worn koiguchi is to use the same kind of wood from which it was originally made. Take a shaving of well-seasoned magnolia wood about 3/4" - 1" (2 -2.5 cm) wide and cut it to the appropriate length to fit inside the koiguchi over the worn area. Apply sokui to the koiguchi. Press the magnolia wood into place and hold it firmly until dry. Be careful not to apply too thick of a shaving as this might interfere with proper sheathing. When the time comes for the koiguchi to be repaired again, always be sure to remove all of the previous patch before applying a new one.
Obviously, there are other materials that can be used for first aid repairs to worn koiguchi. The above or just a few. However, before applying anything to the inside of your saya, make sure that it will not harm the sword in any way.
A Few Don'ts When Repairing Worn Koiguchi