Failing to take care of tools can cause tools to rust, bend or get chipped, stick together, dull, and corrode. Bonsai tools are generally expensive and worth taking the time and effort to clean and properly care for. Having tools in good clean condition can also make bonsai work easier and more enjoyable.
CARBON VS STAINLESS
In the debate between carbon steel and stainless steel, many a hobbyist will side with carbon because though it rusts easier, it holds an edge better. Stainless steel looks good and is easier to clean, but looses its edge faster.
There is no right answer to that question, it’s purely a matter of preference (though stainless is almost always more expensive). But regardless of material, all bonsai tools should be kept cleaned, oiled, and sharpened.
Cleaning helps the tools function better, keeps them from harboring disease that might move to other plants, and helps prevent rust.
At the end of each use clean your tools. For professionals, that might be at the end of the day, though they used them on 30 trees. For hobbyists, that may mean three trees. Clean your tools every time after you work with sick material. Moving from one tree to another without cleaning your tools can spread disease to new plants.
(Realistically, how often you clean your tools is a subjective recommendation at best and is also based on practicality. Some people never clean their tools, others clean their tools after each tree. Some of those who don’t clean their tools won’t have any tree or tool loss. Others have and just won’t admit it.)
To clean your tools, first wipe the blade clean with a cloth or paper towel to remove loose soils. Then use soap and water to remove any sap and dry your tools thoroughly.
- If you’ve been working with a tree or plant that is or may be diseased, you may want something more aggressive than soap and water to clean your tools. There are a lot of suggestions on what you can use and any one of them might do the job. Some suggestions I’ve heard include a bleach solution, actually putting the tools under flames, various specialty products, and denatured alcohol or methylated spirits.
My denatured alcohol of choice is plain old rubbing or isopropyl alcohol. The easiest way I’ve kept this available is using a travel hairspray bottle, with all the hairspray removed and washed out and stored with my tool set. That and a paper towel made it easy enough to use after working with any tree. *
- If your tools start to rust, promptly remove any rust with a small piece of steel wool and a little oil (see oils listed below). After removing rust, clean tools again thoroughly with soap and water to remove any residue, oil again, and store properly.
- If you did not catch rust early and you have a larger job on your hands, several rust removal products and erasers are commercially available. After treating for rust, repeat the cleaning process above: wash with soap and water, oil, and store properly.
Tools must be kept sharp so that they cut instead of tearing or bruising the branches or roots of your tree. Generally speaking after buying bonsai tools they’ll likely be sharp for at least a few years if properly cared for. However, working on and keeping your tools sharp is still a good practice. Don’t let your tools get dull before working on them.
Even a cheap pair of carbon shears can be sharpened fairly easily.
Stainless steel can be sharpened but it’s more difficult. To do it you need material that’s harder than stainless steel, such as a sharpening tool with diamond grit. Sharpening tools are frequently graded such as sandpaper with a coarse / medium / fine ratings or similar. Coarse is generally used first or for larger work, then medium, then fine to smooth it out. The principle is the same as sanding woodwork or filing your nails.
Sharpening is frequently done with an oil stone or whetstone. Flat sharpeners are used for flat blades, such as with bonsai shears. Curved sharpeners are used with curved blades, such as knob cutters and concave cutters. You can find these sharpeners for sale with several bonsai tool manufacturers. Make sure to only sharpen the outside of the tool and not the flat inside. Sharpening the inside will create misalignment.
If your needs go beyond a dull blade to a broken tip or similar, you may have success first with a whetstone as indicated above, or you might have luck with a local tool repair service being able to grind it.
The point of oiling your tools is to protect against rust and keep them lubricated so that they work easily.
Different bonsai tool manufacturers and resellers suggest different particular products, but some form of light penetrating oil is what we’re looking for. Triflow and WD40 both do a decent job and both are commonly available. You might also use choji oil or honing oil.
Traditionally, the Japanese cleaned fine blades with choji oil. You can buy choji oil today and it’s a fine thing to work with. Know though that choji oil is basically made of a clove oil and fine mineral oil at a rough ratio of around 1:10 to 1:100. So you can buy choji oil, you can just use fine mineral oil. Or if you’re feeling really festive you can also get yourself some clove oil and put some drops into your fine mineral oil.*
To apply, put a drop of oil in the joint or hinge first, then apply a bit of oil to a clean cloth (old T shirts, rags, or an old wash cloth turned work perfect for this). Wipe the oil into the joint, and then put a light coating onto the whole tool. Wipe any excess oil off with your cloth. Be thorough in wiping them down before storage or your tool roll will end up greasy!
As a last note, this is probably obvious for many but may be new for a few out there. There are different kinds of oils. Penetrating oil, honing oil, cooking oil, and mineral oils all have different properties and are not interchangeable.
- Check your bonsai tools out each time you use them or store them to identify any damage or problems early. Care for them when they need help promptly.
- Tools shouldn’t be stored together in a jumble because they can hit on and damage each other. Proper storage keeps each tool protected in it’s own space. This is frequently accomplished with a leather or cloth tool roll.
- Tools should be used for their intended purpose. The most classic example is cutting wire with, well, really anything other than wire cutters.
- Don’t force tools into doing a larger job than they were intended for. You may get the job done, but in the process break the tool. More likely, the tool doesn’t snap in two, rather you might bend smaller parts of your bonsai tools and create misalignment. If you’re using a delicate pair of shears you might need to go up to garden clippers for a fatter branch, or up to a saw for a something still larger. A good rule of thumb is don’t use two hands to make a cut. (Unless your tool was designed for use with two hands like lopers or a saw). It is better to cut a little at a time than to grasp the whole and chop at it and squeeze with both hands. Bonsai tools also come in different sizes. If you’re beginning to work with larger trees, consider investing in larger tools.
- When possible do not store tools where it is humid. It makes them prone to rust and corrosion. That isn’t to say, I live in Florida, it’s humid wherever I go. Rather it’s saying if your basement is considerably more humid than your garage, keep the tools in the garage.
With the right care, high quality tools can last a lifetime. If you want an excuse to get yourself some new tools, ignoring rust on carbon or sharpening on stainless is the way to go.
* With a nod to the folks at poison control, and for the sake of safety please do not put chemicals in reused empty food or drink containers.