Aluminum-Oxide oil stones are very popular man-made sharpening stones produced by an abrasives company called Norton and which are commonly called India Stones. Generally less expensive than Arkansas stones (aka Novaculite), these stones are graded coarse, medium, and fine and are designed for fast cutting. Yet, when the fine grit is used, they can also produce a relatively fine edge. Also, because India Oil Stones are both softer and coarser than Arkansas Stones, they are commonly used in conjunction with Novaculite to cut the initial edge bevels or, repair extremely dull or damaged edges before refining and polishing the bevel with an Arkansas Stone.
In addition, the Chisora 1,000 is absolutely delightful when using it. Professional chefs and wood workers, have reported exemplary results. Unlike other stone sharpeners, these ones don’t need soaking in water. You only have to lubricate it, and you are ready to sharpen your knife. Once you start sharpening your blades with this stone, you will never choose any other product. They are that addictive.
You will also need at least one finer stone. Once the shape of an edge is established, successively finer grits are used to refine the edge improving the quality of the cut it delivers. A dull edge will not cut well and should be shaped with a coarse stone. An edge sharpened on a coarse stone will cut better than a dull one, but still won’t be ideal and should be improved with a finer stone. As you progress through finer stones, the cutting edge will continue to improve. How many and how fine these stones need to be varies depending on how fine an edge you require.
Our favorite way to sharpen a blade is to use a whetstone—a rectangular block that works almost like sandpaper, helping to straighten and refine the cutting edge on the blade as you slide the knife across it. Most whetstones are designed to be soaked in water before every use, so check the manufacturer's instructions to be sure. (Fun fact: Whetstones aren't actually named for the fact that most are used wet—"whet" is actually just an old word for "sharpen").
Now turn the knife so that the blade is no longer pointing towards your body. Continue to maintain the angle of 10 – 20 degrees and the gap of approx. 5 mm from the back of the blade to the sharpening stone. Slide the cutting edge up and down over the sharpening stone. Grind both sides of the blade alternately, around five to ten times on each side.
Whetstones may be natural or artificial stones. Artificial stones usually come in the form of a bonded abrasive composed of a ceramic such as silicon carbide (carborundum) or of aluminium oxide (corundum). Bonded abrasives provide a faster cutting action than natural stones. They are commonly available as a double-sided block with a coarse grit on one side and a fine grit on the other enabling one stone to satisfy the basic requirements of sharpening. Some shapes are designed for specific purposes such as sharpening scythes, drills or serrations.