Whichever method you choose, be it a waterstone (also known as a whetstone), or a pull-through (either V-shaped or ceramic wheels) it's important to regularly hone your knife with a honing steel, which we'll also cover below. You'll be pleased to hear that you won't have to reach for the stones too regularly – once every two or three months should suffice.
Put the pointed, narrow end of the sharpener up against the open end of the gut hook. The narrow, pointed end of the sharpener should face in toward the thickness of the blade, away from the edge of the gut hook. Match the angle of the sharpener to the original edge angle. This will maintain the correct sharpening angle and prevent you from getting cut by the blade tip. Hold the same angle when sharpening each side of the gut hook.
Historically, there are three broad grades of Japanese sharpening stones: the ara-to, or "rough stone", the naka-to or "middle/medium stone" and the shiage-to or "finishing stone". There is a fourth type of stone, the nagura, which is not used directly. Rather, it is used to form a cutting slurry on the shiage-to, which is often too hard to create the necessary slurry. Converting these names to absolute grit size is difficult as the classes are broad and natural stones have no inherent "grit number". As an indication, ara-to is probably (using a non-Japanese system of grading grit size) 500–1000 grit. The naka-to is probably 3000–5000 grit and the shiage-to is likely 7000–10000 grit. Current synthetic grit values range from extremely coarse, such as 120 grit, through extremely fine, such as 30,000 grit (less than half a micrometer abrasive particle size).
This is a good size stone and has the two different grits needed for knife sharpening. No instructions were included, but there are many websites with written and video instructions, so this is not an issue for most people. A fair amount of dust is generated during the sharpening process, so protect the work surface and wash the knife after sharpening is completed.
The height of the spine of your knife off of the stone below it will determine the angle. A typical sharpening angle for a typical chef knife is 19 or 20 degrees per side. For the sake of removing confusing obstacles that could hinder your progress, let’s just sharpen your knife at 20 degrees per side. You can determine exactly how high off the stone that knife should be held by measuring the height of your blade at the heel and then dividing that number by 3 for a 20 deg angle.
You need a stone holder, something that can be purchased for as little as $20.00 to keep the water stone is place as you sharpen. A lot of water stones come with a base, so there’s so need to get it separately. Some people just have the stone on a piece of wood over a container of water with a cloth underneath the stone to keep it from slipping. The key is that you don’t need to spend a lot of money to get started and you don’t need Naniwa Chosera stones, you can start with King water stones if you like, those are fine and I don’t mention King in an attempt to say they are inferior in any way. The key to learning is not what you are using, not the quality or brand of stones, it is developing consistency with a technique that you can use comfortably and repeat. Saying that, stay away from the seven dollar stones available at the hardware store. (Remember, I tried everything).
Now you may wonder, if a finer stone produces a better cutting edge why do I need a coarse stone at all? The answer is that finer stones work much more slowly than coarse ones. The amount of metal a fine stone removes with each pass is much less than what a coarse stone removes. If you have an edge with a good shape to it from a coarse stone, this is not a problem because the fine stone doesn’t have to remove much metal to improve the edge. If the edge is dull, it will take many times longer to reshape it with a fine stone than it would with a coarse one.