The Iaido Journal  May 2002EJMAS Tips Jar


Copyright © Kathleen D. Fowler 2002. All rights reserved.

    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:

  1. It is seated snugly in its hole
  2. It is not crooked
  3. It is not extending out from the hole (this could be a sign that it is working its way out)
  4. It has no cracks or other signs of damage
  5. It has been inserted properly [from the ura (the side that is facing you as you wear the katana), not the omote (the side that is facing out as you wear the katana)]:  this will reduce the chances of the retaining peg  falling out during  nukitsuke, etc.
  6. It has a good color.  A good quality mekugi made from strong bamboo will be an amber color. A bad mekugi made from weak bamboo will be a light beige or egg shell color.  Bad mekugi should be replaced at once.
Always keep a couple of extra mekugi in your katana repair kit, just in case.

Where to Get Mekugi

  1. katana and mogito suppliers
  2. sword shows
  3. make your own
How to Choose a Strong Mekugi
  1. The color should be amber.  The lighter the color, the weaker the bamboo.
  2. The grain should be small and tightly packed.
  3. There should be no cracks, dents, or other imperfections of any kind in the wood.
  4. Be sure that it is the correct size for your katana.  It should fit snugly in the retaining peg hole.

Rule of Thumb:  If it looks like a piece of a cheap chopstick, don't use it.

Making Your Own Mekugi

  1. Start with good bamboo.

  2. a.  The bamboo plant should be at least three years old.
    b.  It should be straight.
    c.  It should be growing in a sunny location.
    d.  It should have a wall at least 1/2" (1.2 cm) thick.
    e.  The grain should be small and tightly packed.
  3. Cut the bamboo near the ground.  The section between the roots and the first joint is the strongest and makes the best mekugi.
  4. Cut off the bamboo above the first joint and do with it as you please.
  5. Allow the bamboo to season in a dry, shady place until it is a nice amber color.  This usually takes 6 months to a year.
  6. When the bamboo is sufficiently dry, split into segments (half, quarter, eighth, etc.). I've found that Japanese nata work really well for this.
  7. Take one section at a time and use a saw to cut it into about 2" (2.5 cm) long pieces.
  8. Using a knife or other similar tool form blanks from each 2" (2.5 cm) long piece by splitting along the grain.  Each blank should be approximately 2" long X 1/2" thick X 1/2" wide ( 2.5 cm X 1.2 cm x 1.2 cm).
  9. Again using a knife, remove the outer skin of the bamboo from each blank, but be careful not to remove too much.  The part of the bamboo near the skin is stronger than the part near the center hollow section.  Therefore, the outer part of the bamboo is the best part to use for making mekugi.
  10. Again using a knife, split off slivers of the bamboo until it is roughly round in shape.
  11. Since the diameter of retaining peg holes can differ slightly from one katana to another, it's a good idea at this point to compare the size of the peg with the size of the hole.  Keep removing splinters of wood until the new peg will fit snuggly in the hole.
  12. Tsuka come in various thicknesses, so be sure that your mekugi is the right length to sit flush with the surface of the tsuka on both sides. If it is too long, cut it to the right length.
  13. Slightly taper one end.
  14. Smooth out any rough edges.

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

  1. Take a small amount of one- to two-day old cooked short-grain rice and place it on a clean, flat surface.  A board works well.
  2. 2. Wet a strong, flat stick, such as a bamboo spatula and mash the rice.
  3. Add a drop or two of water, and mash again.
  4. Keep adding water as needed.
  5. Continue mashing the rice until it becomes a sticky, glutinous mass with no lumps.
  6. You now have basic sokui.

Advantages of Using Sokui for Various Repairs

  1. No fumes.
  2. Does not draw moisture.
  3. Is strong but can be removed for 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.

  1. Wash the affected area thoroughly with an oil free soap (available at your pharmacy).  A soap containing oils can spread the urushiol.
  2. Follow by further cleansing the area with rubbing alcohol.
  3. Apply calamine or other similar soothing, medicated rash lotion.
  4. Don't scratch!

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

  1. Use a small sliver of wood to spread a bead of sokui over the necessary area.
  2. Press together the pieces to be glued. Hold them firmly in place using a cord, rubber band, or other similar device until dry.

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.

Method 1

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.

Method 2

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.

Method 3

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

  1. DON'T use any glue which gives off corrosive fumes.
  2. DON'T repair the koiguchi with any substance that might scratch, rub, or wear the metal of the habaki or the blade (example: guitar picks).
  3. DON'T expect any first aid repair to last forever.  The more often you practice, the more often you can expect to have to make repairs.

Kathleen D. Fowler is a Lecturer in the Department of English, Kagoshima
Immaculate Heart College
TIJ May 2002