Bonsai Repotting Sickle  

Edge Angle

The Repotting Sickle is used for bonsai work, and is easy to sharpen by hand using a half-round or round machinist’s hand file.


A 6" smooth cut, half-round machinist’s hand file is useful to carry in your gardening tools box. Use it to resharpen the tool as needed throughout the gardening activity.

 

 

Bonsai teaches us to look beyond what is immediately apparent.

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General Guidelines
Tool α Notes
Repotting Sickle 25°

If sharpening this tool on the Tormek, it will have to be done by hand: the inside edge is best to sharpen on this tool. This is the part marked red in the picture above.

The edges will need to be deburred using a very fine machinist's hand file, or it can be honed using the honing wheel on the Tormek.

Note: The tool shown above to the left works well for right-handed gardeners as it is held in the right hand whilst swinging it. For Southpaws, the tool may work better if the bevel is on the opposite side.

Notes & Comments

Tormek Notes

The Tormek SG-250 grindstone works well for sharpening this tool.

If sharpening this tool on the Tormek, it will have to be done by hand.


Shaping the edge

Japanese gardening tools are typically made from high-carbon steel which is not terribly hard. When this is combined with an acute angle like 30°, it is easy to damage the edge.

Changing this tool to have a higher angle like 45° is not recommended. Instead, the gardener should use a different tool, especially where the blade could come into contact with hard objects such as gravel. These could impart significant damage to the blade of this tool.


For removing large nicks in the edge, a Tormek grinder or a 12-14" bastard file machinist’s hand file will work sufficiently well. Experience has shown that either of these approaches works quite well in removing nicks from the edge after my wife or children have used the tool.

One common problem is that the pointed end of the cutting edge gets rounded over. If this happens, the back side will need to be reshaped to get the end back to a point. The side needing to be ground is shown to the right with the red arrow. The side of the tool is flat ground, keeping the edge angles as they were originally made.

There is a Tormek video on YouTube, Tormek Live Sharpening Class - Part 15. Repair a damaged knife, which outlines such reshaping activities quite well.

This may seem an onerous task, but it only takes a few minutes, and the usefulness of the tool will be maintained.

Using a bench or angle grinder is not recommended as this will surely overheat the tool, removing the temper from the edge. Additionally, the shaping of the edge is difficult to control.


Sharpening the edge

KJ-45 Bottom Stop

If using a Tormek with the KJ-45 jig, the bottom stop is recommended (as indicated in the picture to the right). This makes setting the angle easier.

If you choose to use a machinist’s hand file,

  1. Start with a 8-10" medium (or second cut) file.
  2. Finish with a 6" smooth cut file, then use this file to remove the burr.

Micro bevel Notes:

A micro bevel could make the resharpening of this tool easier if resharpened away from the other sharpening tools. Even if the tool was sharpened in the shop using a Tormek, the gardener could use a machinist's hand file for a quick touch-up. In general though, it is not needed on this tool.


More Information

Videos & Presentations