[2026 Edition] Complete Guide to Preventing and Treating Mold on Kendo Armor | A Complete Guide to Causes, Removal, and Preventing Recurrence

When you open your armor bag for the first time in a while, you find white mold on your mask and gloves... Have you ever had that experience?

Kendo equipment is not a cheap purchase, and is an important partner that will accompany you through many years of training. However, due to its structure, it is prone to mold and mildew, and if not properly cared for, it will become covered in mold in a short period of time.

This article provides a thorough explanation of the causes of mold growth on kendo armor, how to prevent it, what to do if it does grow, and storage techniques to prevent it from ever happening again, including the latest knowledge used in the field.

1. The reason and mechanism behind mold growth on kendo armor

First, let's understand the fundamental reasons why kendo armor is prone to mold. Knowing the conditions for mold growth will lead to effective prevention.

Four conditions for mold to grow

Mold grows rapidly when four conditions are met:

• Humidity (70% or more): Armor that has absorbed sweat is in a very humid state
• Temperature (20~30℃): Dojo and storage areas should be kept at this temperature range throughout the year.
• Nutrients: Sweat, sebum, and dust are sources of nutrition for mold
• oxygen: Oxygen exists even inside a sealed armor bag.

In Japan's climate, humidity tends to rise not only during the rainy season but also in winter due to condensation caused by heating, so there is actually a risk of mold all year round.

Why is kendo armor particularly prone to mold?

Kendo bogu is more susceptible to mold growth than other sports equipment due to the following characteristics:

• Cannot be washed in a washing machine: Sweat and sebum tend to accumulate
• Natural materials such as indigo dye, cotton, and leather: Easily absorbs and retains moisture
• multilayer structure: Moisture does not reach the inside of the face mask and gloves, so they take a long time to dry.
• Closed storage: If you leave it in your armor bag, it will get damp.
• 汗の量が多い: The head and palms are areas that sweat a lot.

2. Daily care to prevent mold [Essential routine after practice]

The most important thing when it comes to preventing mold is prevention. Five minutes of care after practice can make a big difference in the lifespan of your armor.

[STEP 1] Always remove your protective gear from the bag after use

The first step in preventing mold is to remove your armor from the armor bag immediately after practice.

The humidity inside an armor bag can reach over 90%, and if left unattended, mold spores will begin to grow within just a few hours. When you return from the dojo, the first thing you should do is spread out your armor.

[STEP 2] Wipe off sweat

What you need:Two clean towels (one wet, one dry)

point:A light spray of alcohol disinfectant spray can help reduce mold-causing bacteria. However, be sure to test it on an inconspicuous area first, as it may cause discoloration of indigo dye and leather.

[STEP 3] Dry in the shade in a well-ventilated area

After wiping, dry immediately in a well-ventilated place in the shade:

• Avoid direct sunlight: Causes indigo dye to fade, and leather to harden and crack.
• Use an armor hanger: Use special hangers for the mask and gloves to allow air to pass through to the inside.
• Blow air with a fan or circulatorCreating airflow speeds up drying
• Stuff newspaper into the small tube.: Efficiently absorbs internal moisture
• Let it dry for at least 3-4 hours: Thoroughly dries not only the surface but also the inside

[STEP 4] Use disinfectant and deodorizing spray

You can prevent mold growth by using a disinfectant and deodorizing spray specifically designed for kendo armor:

• Spray made from natural ingredients(Soybean amino acids, etc.)
• We use indigo dye and leather-safe products specifically for protective gear.
• Spraying too much can have the opposite effect (causing moisture).
• Keep the surface lightly moist

3. What to do if mold grows [Complete step-by-step instructions]

If mold does grow, appropriate measures must be taken depending on the extent of the mold.

Checking the progress of mold

First, check for mold:

How to remove mild mold [5 steps]

What you need:

• Mask and rubber gloves (required)
• A soft brush (such as a toothbrush)
• Neutral laundry detergent (for delicates)
• Disinfectant ethanol (*Be careful with indigo dye and genuine leather)
• Several soft cloths
• newspaper

Moderate to severe mold: Consult a professional

If you experience any of the following issues, we recommend that you consult a professional before attempting to fix the problem yourself:

• Black mold is widespread
• There is a strong musty smell that doesn't go away even after drying.
• It penetrates to the inside of the men and kote
• I want to avoid risks with high-quality armor (hand-stitched, indigo dyed, genuine leather)
• No matter how many times you clean it, it keeps coming back

For more details, please see "5. Cases where professional cleaning and gas sterilization are required."

4. Mold prevention and maintenance methods for each part

Each piece of protective gear is made of different materials and has a different structure, so there are different care methods that are appropriate for each part.

Preventing mold on masks

The face is the part of the head that absorbs the most sweat, and the inside in particular is a place where mold is likely to grow.

• Focused care on the inside: Wipe the areas that come into contact with your chin and forehead every time.
• Base of the menhimo: Mold tends to remain, so clean it carefully with a soft brush.
• Preventing rust on the metal faceplate: Minimize water and always wipe dry after wiping
• Removable parts: If the face cover can be removed, separate it and dry it.
• Utilizing armor hangers: Store upright to allow air to circulate inside

Preventing mold on trowels

The foreskin absorbs sweat and sebum from the palms of the hands, and the inner part of the hands is particularly prone to mold penetration.

• Putting your cards first: Always wipe down and disinfect with a disinfectant spray
• Drying the cylinder: Stuff the bag with rolled up newspaper to absorb the moisture inside.
• Leather care: Deer leather is particularly delicate, so keep moisture to a minimum.
• Dry the left and right sets togetherStore upright in a well-ventilated place

Measures to prevent mold on the body

The body is relatively resistant to mold, but you need to be careful of the seams and folds.

• Responses depending on the type of dodai: Varies depending on bamboo body, fiber body, and Yamato body
• Checking the seams: Moisture tends to accumulate at the connection point with the waist cord.
• Don't forget the inside: Wipe the chest area regularly
• Store upright: Ensure air flow

Measures to prevent mold on sauce

The tare part has a structure that makes it easy to spread out, so it dries out more easily than other parts, but you should still be careful.

• Spreading the Otare and Kotare: Open the folds to let air in
• Seams and folds: Check carefully as mold is likely to remain
• Name tag area: Please note that the embroidered area is difficult to remove moisture from.
• Store on a hanger: Keeps the expanded state

5. Cases where professional cleaning and gas sterilization are required

If the mold is severe or if the armor is high-quality, hiring a professional company will ensure safe and reliable mold removal.

Criteria for deciding whether to hire a specialist

Benefits of specialized kendo armor cleaning

• Washing according to the material: Treatments suited to indigo dyeing, leather, and core materials
• Disinfection to the inside: Cleans not only the surface but also the depths of the fibers
• Complete removal of moldy odor: Eliminate odors from the root with ozone water and special detergents
• Dedicated drying equipment: Technology that completely dries the core material
• Extending the lifespan of armor: Long-lasting with regular maintenance

Gas sterilization option

Gas sterilization is a method of inactivating bacteria using a special gas without using water. This sanitation technique is also used in medical settings and is effective in preventing mold on kendo armor.

• No water used: Safe for delicate materials such as indigo dye and leather
• Penetrates deep into the interior: The gas penetrates deep into the fibers, inactivating bacteria inside.
• Effective against strong moldy odors: Particularly effective against odors that cannot be removed by washing
• Reduced risk of recurrence: Prevent recurrence by treating internal bacteria

Points to consider when choosing a specialist

• Do they have a wealth of experience cleaning kendo armor?
• Are the measures to deal with mold and odors clear?
• Is the work process explained in detail?
• Are there any before and after examples available?
• Are prices and delivery times clearly stated in advance?

reference:BUSHIZO offers a specialized cleaning service for kendo armor called "Kensen."
↓Click here for details!!

6. Storage method to prevent mold from growing again

Just as important as daily care is proper storage.

How to choose a storage location

• A well-ventilated place: Avoid the back of the closet and place it in a place where there is good air circulation.
• Humidity management: Use dehumidifiers and desiccants to maintain humidity below 60%
• Little temperature change: Choose a location where condensation is unlikely to occur
• Avoid direct sunlight: Prevents indigo dye from fading

How to use the armor bag

For long-term storage (off-season, after retirement, etc.)

• Air out once or twice a year: Allows moisture to escape and prevents mold and insect damage
• Ideally, store it in a paulownia wood box.: Humidity control, antibacterial, insect repellent
• Regularly replace dehumidifiers: Maintains a state where it can continue to absorb moisture
• Use insect repellent in combinationNatural materials are at risk of insect damage
• Dry completely before storing: Even a small amount of moisture remaining is dangerous

Special measures for the rainy season and summer

During humid weather, extra care is required:

• Allow a longer drying time after practice (at least 4-6 hours)
• Actively utilize the dehumidifying function of dehumidifiers and air conditioners
• Store the armor unfolded (do not put it in a bag)
• Dry the entire item in the shade once a week
• Increase the frequency of disinfectant sprays

7. Frequently Asked Questions (FAQ)

Q1. Can I use mold remover for the bathroom?

A. Never use chlorine-based mold removers. They are not suitable for kendo bogu and can cause the following problems:

• Indigo dye fades significantly
• The leather hardens and deteriorates.
• Metal fittings corrode
• The fabric is damaged

Q2. Is it okay to wash the armor completely?

A. Generally, we do not recommend this. In particular, if the inside of the face and the kote get wet, they will be difficult to dry, and the core material will retain moisture, which may actually cause mold.

However, washable protective gear and full-body washing services at specialty stores are exceptions. The basics of normal care are to wipe and dry thoroughly.

Q3. Will continuing to use moldy armor have any adverse effects on my health?

A. Yes, there is a health risk. If you continue to inhale mold spores, you may experience the following symptoms:

• Allergy symptoms (sneezing, runny nose, itchy eyes)
• Respiratory problems (cough, asthma-like symptoms)
• Dermatitis and rashes
• Headache and fatigue

If you discover mold, we recommend that you take action as soon as possible.

Q4. Can ethanol be used for indigo dyeing?

A. Generally, avoid using it on indigo dyes or genuine leather, as there is a high risk of discoloration or staining.

If you absolutely must use it, be sure to test it on an inconspicuous area and use only a small amount at your own risk. This should only be used on areas that are chemical-based or where there is little risk of color fading.

Q5. What must I do to prevent mold from recurring?

A. Make sure you do these three things:

1. Always remove the protective gear from the bag after practice
2. Wipe away sweat and dry completely
3. Store in a well-ventilated place

Ultimately, the most effective way to prevent mold is to "avoid leaving moisture."

Q6. Is it necessary to prevent mold even with new protective gear?

A. Yes, it is. Even new armor will absorb sweat and trap moisture with use. Taking good care of it from the beginning will help keep your armor looking beautiful for a long time.

8. Summary: Taking care of your armor means honing your mind

In Kendo, it is said that "it begins with a bow and ends with a bow." This applies not only to other people, but also to your own armor.

Carefully caring for the armor you use in training is not just about managing your equipment, but is also a part of your training to improve yourself. The accumulation of small daily care tasks not only helps your armor last longer, but also develops your mindset as a swordsman.

By following the advice in this article, you can protect your precious kendo armor from mold and keep it clean for a long time. Starting today, don't hesitate to take the time to keep your armor and your mind clean.