TIPS FOR USING THE GRINDING DISC
First, clean the surface of the potter's wheel thoroughly. If there are small pieces of anything on the wheel head it will cause an up and down wobble, and that will be transferred to to what you are grinding.
Attach the “low head bat pins” to the wheel head. Regular bad pins will not work because they will stick up above the steel disc. I suggest screwing them down rather than just dropping them in.
Place the steel plate onto the attached pins, just like you would a throwing bat, making sure it has nothing on it that would cause wobbling.
Place the diamond grinding disc on to the steel plate, taking care to center it as closely as possible. The diamond disc will attach to the steel plate by magnetic attraction and will not come off during use.
Arrange a means of dripping water onto the disc. This can be as simple as a squeeze bottle, or if you are using the disc regularly, run a plastic tube from a container (like a plastic bucket) to the center of the disc.
The individual diamond particles are much harder than any ceramic, and since you are using all portions of the wheel due to its precision. It should never completely wear out. They do, however, over time become “dull” because tiny pieces chip off and leave a less sharp cutting edge. This can be remedied some by reversing the direction of the potters wheel for an hour or two of use from time to time, thereby using a different edge on the diamond particles.
Keep the plate and discs dry to prevent rust. If it does start to rust, sand it and spray a thin coat rust inhibiting paint or apply wax, making sure the surface is smooth.
The photograph at the bottom of this page shows a large chip in the bottom of a vase before and after it was ground away, taking about 2-3 minutes to accomplish. The video is not the best quality, but you should get the idea of how it works.