Unfortunately, the arrays of modern whetstone can be bewildering to the inexperienced sharpeners that so often times many of them end up with a crap or wrong decision on stone type for their utensils. The most difficult to determine is whether the whetstone is fake or fabricated with low quality of materials. To avoid this you can only go for the reliable brand of a whetstone. 

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.
A: When it comes to the best knife sharpeners used in a domestic setting the abrasives used to sharpen the blade should last for quite a few years. When they do eventually wear out many of the best manufacturers will refurbish them for you, typically for a nominal fee. Again, however, unless you are using the sharpener on a daily basis (and there is virtually no reason the average person would do this), the sharpener should last for many years before ever needing service.
Clauss DualDrive is the first non-chuckable sharpener for Clauss DualDrive is the first non-chuckable sharpener for both #2 and carpenter pencils. Just use with your current bit on the fly. Manual or power-driven design evenly sharpens. Integrated shaving reservoir with see-through window. Features high carbon steel blades and a lifetime warranty.  More + Product Details Close
It is better to understand the difference in sharpening stone materials before you are going to make any decision. Among the available options in the market today, Waterstone, oilstone and diamond stone are the most common type of sharpening stone. Each of stones comes with advantages and disadvantages. Waterstone and oilstone are available in natural and synthetic models. Synthetic are the most common and easy to find as man makes them. As the use of natural stones (e.g. original Arkansas or Japanese natural whetstones) is has diminished in popularity, they are beginning to rare in the market. Artificial stones have a more consistent particle size and controlled with a tight mechanism in providing high-quality sharpening stone.
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. 
I bet those Vikings, relatives of mine no doubt, never had it so good. They never had surated blades to sharpen or needed to wear cool things around their necks to woo the women (they just grabbed them by the hair I guess). I love my stone. So useful and beautiful. I always have spit to wet it with, and I always have a way to sharpen my tool. Wazoo makes high quality products. I give them the highest rating I have. Dudes!
Your immediate goal is to raise a burr on the side of knife opposite to the side you are sharpening and depending on the steel, the grit of stone and how you are doing, it will be either a very quick process or it will seem like it takes an eternity. Patience here will reward you, believe me. The sharpening process is incomplete with no burr creation on your first stone. (Yes, it is possible to stop at that magic moment without the burr forming but we are not there yet, we don’t even need to go there, ever, I am just mentioning it so those gifted sharpeners will be happy) . Think of the burr as the debris that is making the knife dull being forced down the blade towards the edge and over to the other side of the by your sharpening prowess. You form the burr, that knife will get sharp, no burr, you just need to look at your work. A Loupe is handy here, an inexpensive magnifying device with a light that allows you to see the edge very well, if you are not forming a burr, you are not reaching the edge. (Having a loupe also makes you look cool and scientific, like a Sharpologist).
A sharpening stone is made of particles of abrasive material that are sintered or bonded together. The blade is moved across the stone and the steel is worn away, which creates the edge. However, at the same time, the stone is also worn away to reveal new, coarse particles. As a general rule, the softer the stone, the more rapidly it will wear and will be more aggressive in use. Harder stones don’t wear as quickly.
I would say they are worth the money. Go for it. I took a blunted Pampered Chef kitchen knife from completely dull to razor sharp in about an hour (of bumbling and repairing mistakes LOL) heavy grinding. If you have a severely damaged blade, grab one of those cheesey two sided stones from Harbor Freight to do your heavy grinding. From there these stones will work very well.
Clamp-style sharpening tools use a clamp with several holes with predefined angles. The stone is mounted on a rod and is pulled through these holes, so that the angle remains consistent. Another system is the crock stick setup, where two sticks are put into a plastic or wooden base to form a V shape. When the knife is pulled up the V, the angle is held so long as the blade is held perpendicular to the base. Several cutlery manufacturers now offer electric knife sharpeners with multiple stages with at least one grinding stage. These electric sharpeners are typically used in the kitchen but have the ability to sharpen blades such as pocket or tactical knives. The main benefit of using an electric sharpener is speed with many models that can complete the sharpening process in one to two minutes. The disadvantage is that the sharpening angle is fixed so some specialized knives, like a Japanese style Santoku, may need additional attention to sharpen to the ideal angle.
An important but often confusing area of sharpening is knowing when you're done with one stone and ready for the next finer grit. On coarse stones it is very easy. When you sharpen one side you will notice a burr forming on the opposite side of the edge. This burr is hard to see but is easy to feel. Very carefully feel for the burr by gently running your hand from the spine to the edge. (Do not run your finger along the knife edge from heel to tip, that's only asking for trouble!) A burr is formed when your stone removes material directly at the edge. The burr will move from one side of your knife to another as you alternate sharpening sides. Make sure you have felt the burr jump between both sides before you move on to the next finer stone. That will ensure that you have sharpened both sides effectively. The finer grits are done the same way but the burr is much smaller. On the finest grits you may not be able to notice the burr at all. Testing the knife sharpness will tell you when you're done. (Learn how you can test to see if your knife is sharp.)
Identify the bevel angle of the blade, better known as the "rough grind angle." Every knife is at a particular angle to suit all your needs and purposes. The majority of the pocket knives have a bevel edge is 25 to 30 degrees. Call the manufacturer of the knife if you are "weary" of this. Or go online and find a specific bevel angle chart. Nevertheless, when you find the bevel, you'll see the blade is honed into it for obvious purposes. How to sharpen a pocket knife begins with learning angles.

The composition of the stone affects the sharpness of the blade (a finer grain, usually, though not always, produces sharper blades), as does the composition of the blade (some metals take and keep an edge better than others). For example, Western kitchen knives are usually made of softer steel and take an edge angle of 20–22°, while East Asian kitchen knives are traditionally of harder steel and take an edge angle of 15–18°. The Western-style kitchen knives are generally in the range of 52–58 on the Rockwell scale, which denotes the relative hardness of a material.

A: That depends almost entirely on how often you use them. If you are a professional chef who uses his or her knives every day then you should hone them every time you use your knives. But honing has its limits and over time your edge is going to become dull no matter what. Therefore your knives will need to be sharpened at least several times a year. Some chefs, in fact, will use a whetstone on an almost daily basis in order to ensure their knives are always razor sharp. Most of us, however, are not professional chefs and may not even touch our kitchen knives for days at a time. In that case, it’s probably a good idea to hone the edge after every couple of uses and have your knives sharpened once a year.