Winter is a good time to keep up with maintenance on an assortment of bonsai tasks. It is a good time to spray for fungus, clean benches, break for wine, clean pots for repotting, make soil, break for more wine and clean and sharpen tools for the new season. Cleaning and oiling of tools will keep them in good order. It is also a good time to disinfect them. A good soaking in alcohol, hexol, or dilute bleach will get rid of the critters lurking in your tools.
Why is this important?
It is important because many of the species we work on are delicate to blights, and blights can be transferred by dirty tools. Most susceptible are those of the rose family – Pyracantha, apples, pear, quince, plum, apricot, cotoneaster and hawthorn. Fire blight is the worst and fastest growing of the blights and will destroy a plant in its entirety and is not forgiving. Cutting away damaged portions of the plant well below the blight can stop the blight but once in the plant is much like Virticillium wilt meaning that since this is bonsai, cutting away branches is not really an acceptable way to deal with the disease.
So the tools have soaked and are disease free for now. Time for a good cleaning. I use oooo steel wool. This will remove the worst of the rust and leave the metal bright and shiny. Grit blocks and fine sandpaper can be used for especially pitted and rusty areas, but one should not their tools get to this point.
If the tool needs sharpening this is the time to do it. I am not a big advocate of continual sharpening of my tools since I do not use them in such a way as that they get so dull I can’t use them. Trimming tools like shears will need the most sharpening while edge tools like concave cutters and wire cutters may never need sharpening. If one is continually sharpening a pair of concave cutters, that person may wish to invest in a good fine tooth Japanese pull saw for removal of larger branches.. I find that when a concave cutter is not cutting properly it is usually an alignment problem rather than a sharpening problem. Alignment problems stem from cutting large branches with force, springing the jaws. A couple passes with a diamond impregnated sharpening rod will restore an edge just fine. Do not use the carbide sharpeners since they work by removing a thin roll of metal from the edge. Bonsai shears are not adjustable enough to use that kind of tool very often.
Now that the tools are clean and sharp, we can continue with making them more water proof against the rust. Most iron Japanese tools come in a black finish. This is done at the factory using many salts in a hot process to build a black iron oxide coating on the iron to prevent rust. This in conjunction with a good oil will easily last a full season. I use a cold bluing kit for touching up the bluing on guns. It works well and provides an even color over the tool. With the addition of a good oil the tool looks as good as the day you bought it.
After cleaning the tools with the steel wool I had some of my tools actually resist the cold blue by beading up. Thats how good a good gun oil like Hoppe no. 9 can be. That stuff is invalauble for longevity on a tool in a really bad environment. Tool treated with WD40 or three in one oil will not hold up over the long haul. I have heard that Marvel Mystery Oil is also very good for keeping tools oiled over a long period of time. When the tools resist the blueing just wipe them down with more solvent and try again.
After oiling I roll mine up in newspaper and then a cloth and place them in my bag till I need them for repotting and the rest of the season. Keep them dry and out of moisture….Justin Case
This is a pic of the items used to clean , blue and oil the tools.
This is a close-up of the cold gun blue. This product has been around for a long time. I have had this bottle for thirty years. It is almost gone, about 1/4 inch left in the bottle. I think I got my monies worth.
Here is a pair of shears with most of the blue worn off from use. Japanese tools with heat applied blueing from salts will only require touch-up, while iron tools like these Corona’s that were never factory blued will wear off in a season.
Here they are after the cold blue is applied. It does a great job and once oiled it will last several years. I do mine about every other year. They didn’t get much use last year with the stones and cancer in the family. This year I hope to see the tools all silver by Fall.
Here is some superficial rust that will grow in the places hands can’t keep it buffed off. Keeping up with oil after use will cut down on this type of rust.
Here is just the top handle blued so one can see the difference.
The tools are now all cleaned up and ready to be packed away until I need them. I will wrap them in newspaper and then a towel and keep them in my bag until needed. Once I have used them I will clean and oil them before putting away. They will last a lifetime if cared for properly. Many of these tools are thirty + years old and still cut like the day I bought them. Most of my older tools are Kiku, which made very fine Ikabana and Bonsai tools in the Fifties thru Eighties. They are hard to find now.