The type of stone refers to the material it is made with. You can find many different types, including diamond, ceramic, natural stone, and synthetic. I would only suggest diamond if you’re planning to be sharpening only ceramic knives. Many of the stones you’ll find on Amazon or other retails are made of Corundum, which is a crystalline form of aluminium oxide. It’s a fine choice for a beginner sharpening stone.
Lubricate the stone. Some stones specifically use oil or water, and if that's the case, ensure you're using the recommended lubricant. Most importantly, whichever lubricant you choose, do not change it after the first use. When using oils, only use those approved for sharpening stones. Food oils such as vegetable and olive oil should never be applied! Some options like diamond stones, and others, don't need any lubricant at all, so be sure to check the stone's instructions.
In addition, there are three broad grades of Japanese Water Stones consisting of the Ara-to (rough stone), the Naka-to (middle/medium stone) and, the Shiage-to (finishing stone). However, it should be noted that the various grades of natural Japanese Water Stones vary widely in both density and grit size from stone to stone and thus, they do not translate well to American or European abrasive standards. Furthermore, because they are significantly softer than Novaculite, Japanese Water Stones must be flattened more often and do not last as long as a either Novaculite or Coticule stones. But, because they form a slurry of fine particles when used, they also do a superior job of both cutting and polishing.
In summary: Peter Nowlan is a professional knife sharpener based in Halifax (Canada) and he recommends the KnifePlanet Sharpening Stone Set, a beginners and intermediate kit that includes 4 sharpening grits: 400/1000, 3000/8000, a bamboo base and the KnifePlanet Flattening Stone. The Japanese Naniwa 3-stone combination is also a great (and more expensive) choice, ideal for professionals and more advanced sharpeners: the Naniwa stones are slightly bigger compared to KnifePlanet’s. In both cases, a coarse, medium and fine grit combination is very effective to sharpen and refine the edge:
For this type of hand held manual sharpener the 463 does an extraordinary job thanks mostly to the diamond abrasive wheels. You get an edge that’s both razor sharp and burr-free, as if you spent an hour working the edge on an oil stone. If people make a mistake with the 463 it’s that they assume more pressure is needed than actually is. Keep in mind though that it really shines on serrated and straight edged, double bevel Asian-style knives.
A common myth is that sharpening steels actually sharpen knives, and can replace stones or other sharpening devices. Steels actually hone a knife and help keep its edge if used regularly. A steel should be used before and after each knife use for proper maintenance. Easily enough, it's used the same way you use a sharpening stone. To find the proper angle, hold the knife horizontally with the edge touching the steel. Move the spine upward to create a 45-degree angle, and then half that again for your optimal sharpening angle.
The AccuSharp Sharpener is proof positive that you shouldn’t judge a book by its cover. While it looks like something used to attach buttons to shirts it’s actually one of the most cost effective, and we mean effective, means around for restoring a professional edge to your dull knives. It’s compact, screwed together rather than glued and its diamond coated tungsten carbide wheels create an edge that will last.
The humble sharpener tends to elicit more divergent opinions than just about any other type of kitchen tech. Everyone, it turns out, has their own take on which type of sharpener works best and why and most serious chefs aren’t shy about voicing their opinion. As you can imagine then there are a number of things most chefs – both professional and amateur – look for in a sharpener in order to ensure they get the one that’s right for them. These considerations include:
Visually, a very sharp knife has an edge that is too small to see with the eye; it may even be hard or impossible to focus in a microscope. The shape near the edge can be highlighted by rotating the knife and watching changes in reflection. Nicks and rolled edges can also be seen, as the rolled edge provides a reflective surface, while a properly straightened edge will be invisible when viewed head-on.
Functionality – If you have experience with the stick or sharpening stone you likely don’t want or need anything else. If, however, you are in search of an electric-powered sharpener you’ll want to consider how many “stages” you need in your sharpener. In a typical 3-stage sharpener the first stage is the coarsest and does most of the heavy lifting required to turn the edge from dull to sharp. The second stage will have finer grain sharpening wheels. These are used to hone the edge, that is, to smooth out the burrs left by the coarse first stage. A third stage will refine the edge even further and remove any debris left over from the sharpening process.
Over the course of two days I re-sharpened nearly a dozen old blades, including removing the secondary bevel on an old stainless Ontario saber-grind Navy diver's knife, convexing the edge on flat ground 1095 Schrade 55 that also came with a secondary bevel, and fixing a broken tip on an old Kershaw folder. These stones made quick work of the Schrade and Kershaw. Both had completely new edge geometry within 30 minutes apiece. The Kershaw looked like-new, as if the tip had never broken. And the Schrade cut much better than it's secondary bevel would previously allow, regardless of how sharp I got it with a ceramic rod and strops. The Ontario took a little more work, as it had been abused a little the last time I'd held it, over 25 years ago and was as dull as a case knife - one of the reasons I decided to go ahead and do a full saber grind - well, a slightly convexed saber, I suppose would be more accurate. But within under an hour of using the two stones and a couple leather strops (one with black compound, another with green), the Ontario was shaving sharp again too.
Japanese water stones – both natural and synthetic – are known for their superior sharpening performance, not only for Japanese tools, but also on their Western equivalents. The loosely bonded abrasive grit is washed out very quickly, as it blunts during the sharpening process; this exposes new, sharp, particles that can get to work on the blade. Water stones are lubricated only with water! Never use oil!
A good whetstone and a little practice will keep all of your knives sharp and in perfect condition. The beauty is that it doesn’t take much effort to learn, just a good bit of practice to get the angle right and keep a consistent angle while you’re sharpening. Whetstones are available in department stores or online, and while they range in price based on the fineness of the grit, this thread at eGullet can help you pick a good grit to start with.
To use a whetstone you run the knife's blade back and forth across the stone's surface and due to the constant friction with the stone, which acts like a piece of sandpaper, the knife's edge becomes razor sharp and has a brilliant mirror shine. If you are a beginner at using a whetstone it can a take a while to master the sharpening process, so here is a video to help you with your sharpening stone skills.
Once you’ve decided to start sharpening your kitchen knives with a sharpening stone, you’ll need to take the necessary steps to actually get going. These steps include finding and buying the best sharpening stone for use at home, learning the basic technique involved in doing the sharpening, and then practicing enough times to get it right. (For the sake of the knives, we don’t recommend using your best kitchen knives for practice!)
I do have to question the grit ratings of these stones. I didn't notice anything before using them, but after a day, the 2000 grit actually felt courser than the 1000 grit side of the other stone. Whether that could be a byproduct of other factors or an indication of the more obvious, being that the grit ratings aren't accurate, I don't know. But that seemed to be the main criticism of cheaper whetstones, that their grit ratings often aren't accurate. Or maybe it's less a problem with accuracy and more a difference that most synthetic stones might have in common when being compared to much pricier natural stones?
Removing the burr is fairly simple. You'll need a leather strop or block (this sort of thing), which is designed to catch the metal fibres from the knife. You could do it with a fibrous tea towel or some newspaper if you like, but I'd suggest going with leather to begin with. The motion is fairly similar to sharpening. Draw the knife over the leather, going away from the edge at roughly the same angle as when you sharpened.