How do I maintain or clean my whetstones, and how often?

Micro fragments will embed themselves on the whetstone surface, and will appear shiny when left on long enough - that is what we refer to as “load-up”. Most whetstones will eventually load up on the surface, which will appear gray, or black in some cases. The load up comes from debris created from removing materials off of your knives. You can use a diamond plate, nagura, or rust eraser to remove the load-up.