how to sharpen a knife with a stone
If your knives are dull and no longer do their job well or you are worried about cutting yourself, you should sharpen them with a stone. Whetstones, also called grinding stones, are made from natural and synthetic materials and can be used dry, oiled, or wet. Once you have chosen a stone, simply run the dull blades over it until they are sharp again. If you gave them an even hand, your knives will be as good as new!
Choosing a sharpening stone
Examine the knives. Take out the knives you want to sharpen. Determine how dull the blades are so you know what size grit you’ll need the sharpening stone to have. To test the blade, cut into a tomato or piece of fruit and notice how much resistance you get when you cut. The more resistance you feel, the duller the knives will be. 
- You should also consider how often you use the knives. If you use them every day, they are likely to be duller than if you only use them once in a while.
Choose the type of stone. You will want to choose a natural or synthetic stone that can be used wet (soaked in water), oiled, or dry. There are also diamond stones that are really very small diamonds that are attached to a metal surface. Stones that are soaked with water are softer stones, which means you can quickly sharpen knives. Unfortunately, these stones wear out faster than the others. Oilstones are the cheapest and are made of a harder material. 
- Oil stones are a bit more complicated to use and clean, although they do last a long time.
- Diamond stones are the most expensive, but will last the longest.
Choose the grain of the stone. Sharpening stones are available in different grit sizes. For example, you can choose coarse, medium or fine grained stones. You should use a coarse grit stone and then a fine grit if your knives are dull. If they have been recently sharpened or are not very dull, consider using a medium grit. Try to use a grit level between 325 (for coarse grit) and 1200 (for very fine grit). 
- You may be able to choose a stone that has different grit levels on both sides.
Perform sharpening preparation
Follow the instructions that come with the stone. Because there are so many varieties of sharpening stones, it is important to read the instruction manual that came with the stone. The instructions will tell you if you should soak the stone in water or if it should be lubricated with oil while sharpening.
- In general, diamond stones can be used dry or lubricated with water.
Practice holding the knife at a 20 degree angle. Most straight blades should be sharpened at a 20 degree angle. To find the angle, hold the knife directly in front of you so that it is straight up and down. This forms a 90 degree angle. Angle the knife slightly toward the table so that it is at a 45-degree angle. Tilt the knife back slightly so that it is about 1 inch (2.5 cm) above the table. This should form a 20 degree angle. 
- Your knife may require a larger sharpening angle if the blade is very large or thick.
- If you are using a very coarse grit stone, it is advisable to use a shallower (smaller) angle so that you do not over-sharpen the blade.
Take the knives to an expert so they have the best possible edge. Vanna Tran, Seasoned Cook, comments, “I take my knives professionally sharpened every 3 months. You can sharpen yours with a whetstone, but it won’t be the same as professionally sharpening them!”
Soak the stone in water for 45 minutes. If you are using a water stone, place it on a tray and pour water over it so that it is completely covered. Let it soak for at least 45 minutes before you start sharpening the knives. 
- If the stone is too dry you can scrape or cut the blades of the knife.
- Avoid putting an oil stone in water as this can damage it.
Place the stone on a damp cloth. Pour water on a cloth and wring it out. Spread the damp cloth on your work surface and place the stone on it. The cloth will keep the stone in place while you sharpen the knives. Place any type of stone (wet, oil or diamond) on it.
- If you are using a stone with different grains on both sides, place the thicker side up. This way you can quickly sharpen the knives before turning the stone over for polishing.
- It is recommended that you use an old cloth to do this, since you will not be able to remove the grain.
Lubricate an oil stone. If you’re using a stone that needs to be lubricated, you can spray it with oil or pour some directly onto it. Use your fingers to massage the oil into the stone, making sure it is completely covered. 
- You can use oil that is specifically sold as honing or polishing oil. In general, this type of oil is made from mineral oils or non-petroleum products and contains additives that protect the metal of the blades.
- Avoid using cooking oils (such as vegetable or canola oil) to lubricate the stone.
sharpen the knife
Hold the knife against the stone. Use one hand to hold the knife so the blade is at a 20-degree angle. The edge of the blade should face away from you. Place the fingertips of your other hand on the flat part of the blade near the sharp edge. 
- Your fingertips on the blade can control the pressure and direction of the blade as you sharpen it.
Run one side of the blade over the stone. Slowly slide the blade across the stone, making an arcing motion as you go. You want to drag the entire edge of the blade from fore-end to point along the length of the stone so that it is sharpened evenly. Go ahead and run the first side of the blade against the stone until it is sharp. 
- Remember to moisten or lubricate the stone as soon as it starts to feel dry.
Flip the knife over and sharpen the other side. Flip the knife over and run the blade from forend to tip along the whetstone until the blade feels sharp when you touch it with your fingertips. 
- Be very careful when rubbing the edge of the knife against your skin.
Sharpen the knife on a finer grit. If your knives have been very dull and you used a coarse grain to sharpen the edge, it is advisable that you use a stone with a fine grain to polish it. Run the blade against a fine-grained stone from fore-end to tip. Flip the knife over and sharpen the other side of the blade as well. Always sharpen knives evenly so the blade is balanced. For example, if you used 6 strokes to sharpen the first side of the blade, you should also use 6 strokes to sharpen the other side.
Clean the knives and the stone. As soon as you finish sharpening the knives, wash and dry the blades. You should also clean the stone according to the manufacturer’s instructions. For example, if you have an oilstone, you may need to scrub it from time to time with a stiff brush and soak it in oil. In the case of a water stone, rinse off all residue and store it on a dry cloth until you need to use it again. [eleven]
- To prevent knives from dulling quickly, store them in a knife block, on a magnetic strip, or with knife guards