Originally Posted by
mjsorkin
1. I'd soak the stones for a few minutes before lapping them
2. For the initial lapping you need to lap until flat. Make a pencil grid on the stone, and lap very evenly until it's gone. You can repeat if desired. Then chamfer the edges (so they aren't sharp)
3. For cleaning and refreshing the stone you just need a few swipes until the surface looks fresh and clean.
4. Use a figure 8 motion, and rotate the stone once in a while.
That flattening stone is just a course, hard, waterstone. It's surface will wear down a bit with use. Occasionally it will benefit from a bit of lapping on some sandpaper.
Make sure it's flat before you start using it. If it's not flat then you will have to lap it on course sandpaper. Once the lapping stone is flat, it's unlikely to go out of flat again, since it get's rubbed on flat waterstones each time it's used.
Michael