The everlasting question of whether to grind way from or towards the edge is probably as old as the art of water cooled grinding itself. While there are experts insisting that one technique is superior to the other, our tests show there is no noticeable difference between the two in relation to sharpness of the edge. However, there are some essential differences in the grinding operation that you’ll need to keep in mind.
Edge leading is the technique called when the grindstone rotating towards the edge of the tool, leading the water up on it. This technique is ideal for fast grinding because it gives higher grinding pressure. Edge leading tends to activate the grindstone and reduce the risk of a glazed stone surface. The burr developed during grinding is shorter and stiffer in comparison to edge trailing.
Edge trailing is the opposite technique with the grindstone rotating from the edge, creating a trail in the water. This technique is suited for when you need a lighter grinding pressure e.g. when grinding small and delicate woodcarving tools. With this rotating direction of the stone, you can easily observe the burr developing as no water flows over the edge.
The picture shows how the water is led up the tool while using edge leading during sharpening.
The picture shows how the tool creates a trail in the water during the edge trailing technique.
Because each technique has different properties, some tools benefit more from one than the other. Tormek recommends edge leading for most tools while sharpening on our water-cooled systems, as it produces a short, stiff burr. The short burr is easier to remove than a longer one.
However, for delicate tools such as woodcarving tools, we recommend edge trailing. Since these tools require minimal grinding, edge trailing is the ideal technique. Larger tools, such as lathe tools, can also benefit from grinding with the wheel rotating away from the edge. Their size can sometimes make it difficult to grind in a vertical position and therefore using the horizontal position, along with the edge trailing technique, makes it easier to dance with your machine. And as mentioned before, when honing, it is always important to use edge trailing to avoid damaging the honing wheel.
While using edge leading there is a risk of the tools accidentally digs into the stone. This could be avoided with the tool mounted in a grinding jig. Another disadvantage with edge leading is that vibration can occur with steeper edge angles, a problem edge trailing doesn’t have. When honing, it is crucial to make sure the wheel is rotating away from you to not damage or cut in to the material.
Due to the different kinds of grinding pressure and frequent usage, your grindstone will need some maintenance from time to time. Regular maintenance of your stone plays an important role in achieving consistent results. Debris and uneven surfaces can compromise the sharpening process, leading to suboptimal performance. Here are some tips for keeping your stones in top condition: