We invest a lot in good quality bonsai tools. Well maintained, quality tools can last a lifetime. A little regular maintenance goes a long way. With a few skills and TLC we can prolong the life and maintain good, quality function from our tools.

Disclaimer: when inexperienced, cutting tool maintenance can be dangerous and isn’t for everyone. Not only can you injure yourself but you may also flat out ruin a tool. You have to be very careful and have clear intention in your movements. I have developed skills pertaining to this kind of work over many years. In maintaining my katana (I practice martial arts) as well as a long time appreciation for artistry in all forms of cutlery, I learned about blade maintenance and repair and have successfully applied it to my bonsai tools. Tool repair and maintenance is a service that I am starting to offer to others. I’ve spent a lot of time repairing, sharpening and honing my tools. Not many folks have developed these skills and I am happy to help out. It is very accessible if you want to take the time to learn. There is a very special thing that comes from careful attention and tool care that is later reflected in our work. With a bit of common sense you should be all good to maintain your own tools !

My katana being honoured by an Amur maple.

Below, I will denote the tools and steps I take to maintain my bonsai cutting tools. We can then apply elements to our other tools such as wire cutters, pliers etc.

First the maintenance tools. This array of tools makes for a rounded maintenance kit:

  • Clean soft cloth
  • Uchiko tamper/Uchi ball
  • Choji Oil
  • Dual grit stone
  • Leather strop
  • Green leather sharpening compound
  • Japanese anti-rust cleaning block

I will expand on each individually and their respective techniques, in the order they should be used.


Soft cloth

First, start with a good wipe with the cloth. The cloth you use should be clean and non abrasive. An old cotton t-shirt cut into rags or any soft rag should do. I use baby diaper cloth prefolds or soft non abrasive microfibre. Keep the cloth handy as you will need to wipe off debris throughout cleaning.


Uchiko Tamping Ball

This tool is simply a handle with porous fabric wrap containing Uchiko powder. A powder that has just the right abrasiveness to remove oil, grease and dirt build up without damaging the blades.

Hold the tool with one hand and, with the other, gently tap the blades with the ball to disperse some powder evenly.

Then, wipe the powder off the blades to remove debris. Firmly place the cloth around the base of one side with the opening of your fingers towards the sharp edge (making sure they are clear of the blade.) Once you have applied good pressure and have a good position, slowly and firmly wipe towards the tip while maintaining pressure on the cloth to ensure good cleaning. Repeat for the other side.

Caution! Void of protective oil, the metal is now completely exposed to corrosion. Avoid touching the cleaned area with fingers for now.

The Uchiko balls can be purchased along with the choji oil in basic katana maintenance kits. These kits can be found for quite cheap however keep in mind that the powder used in cheap Uchi balls is usually substituted for talcum powder and the result will not be the same.


Dual grit sanding stone

I use these stones for repairing physical damage such as chips or bends or extremely bad edge rolls. For normal maintenance they won’t be needed. Mine is a 400/800 grit and I mainly use the 800 side. When using a stone, always respect the angle of the original edge. Make sure to hold the blade securely at that same angle as you pull across the stone. You may want to practice this on something less important like a pocket knife or cheaper bonsai scissors as this takes some skill and can ruin a blade if not done correctly.

Above, the tip of these scissors is bent, preventing it from closing properly and making a clean cut. Probably due to being dropped or banged against something.

After a little work with the stone, the bend is gone and I am starting to regain the original shape.


Japanese anti-rust cleaning block

If you are going to buy only one thing for cleaning your tools, this is it. Sold by most bonsai suppliers or Japanese knife stores, this thing is a must if you have bonsai tools.

This is a very fine grit sanding block with anti rust properties that will instantly remove all that black resin build up from cutting our trees.

To use it place the tool on a flat surface and hold with one hand.

Using the other hand place the block completely flat on the blade and rub. Make sure you go in the direction of the metal’s grain and keep the block flat to not roll the edge of the blade. Wipe off any debris with the cloth.

Compare this picture to the ones above! They don’t call it the magic block for nothin’!


Leather strop & green compound

Now that we’ve we’ve repaired physical and function issues, cleaned off dirt, debris & residue, it’s time to make our blade edge nice and sharp. A good quality blade will never need actual sharpening (on a stone) unless damaged. Honing however is what we do with the leather strop to bring back a dulled or rolled edge.

Rub the waxy green polishing compound onto the leather to coat it entirely.

Place the strop flat and hone the edge by pulling the blade across the leather at the correct angle. You need to use the blade’s edge itself as a guide to find the angle. The more dull the blade has become, the more agressive an angle may be needed. It’s a skill that involves feeling and watching the edge as it changes. Occasionally feeling the edge with your fingers for sharpness.

Work both sides of the blade back and forth to ensure you aren’t pushing the metal to one side entirely. Sometimes it’s easier to hold the scissors in place and work the strop freely but requires more skill. After honing, wipe off the wax debris with the cloth.

You can make a strop by gluing an old leather belt to some wood. As long as it is real leather. The green compound can be found online easily by searching “green wax polishing compound” you can also use “jewellers rouge” however the green is a finer grit. There is of course an ongoing debate about which is better for which metals blah blah. I use the green on my bonsai tools, sword, Japanese kitchen knives, leatherman’s etc.


Choji Oil

Choji is Japanese clove oil. It keeps the tools lubricated and protects them from oxidization. It also smells incredible.

Finally we coat the blades and moving joints with oil. First ensuring the metal is clean of any debris. Dab some oil onto the cloth and apply from the base of the blade to the tip. Using the same technique as when removing the Uchiko powder. Rub oil into the moving joint and open and close the tool to ensure full coverage. Leave the oil to sit for a minute or two and then gently wipe off ensuring to leave a thin layer.

Choji from Japan is quite expensive in Canada so I make it myself using light mineral oil and cloves.


That’s it! Now our tools will operate at their peak ability and last a long time. As for regular maintenance, a quick clean with the magic block and application of Choji oil is all that’s usually needed. Once in a while hone the edge with the strop and when something gets damaged, re-form with the lower grit stone. I’ve not yet had the need to try and hone wire cutters but they get wiped down and oiled, as with the pliers.

I hope this was helpful to your practice!

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