Step 4: Caring for a knife
As with every relationship of give and take, a knife can take care of you, only if you take care of it. The two basic needs of caring for a knife are cleanliness, and sharpening. This does not mean that a knife needs to be sharpened after every use or that a knife cannot get dirty.
Keeping a knife clean may sound simple enough in theory, but that depends entirely on what kind of knife it is, what it gets used for, its age, or any number of things. When cleaning a knife, avoid fully submerging it in water. Water can get into places that can't be reached easily and begin to form rust. Also if the knife has a wooden handle, or wooden inlays, the wood could swell and warp if it soaks for too long. A soft cloth or a stiff brush with soap and water should be enough for most cleaning. If a knife is beginning to develop rust, a chemical cleaner or light abrasive like steel wool may be in order. Always avoid things like sandpaper or wire brushes, as they could scratch the surface of a blade and create stress points or give rust a place to begin forming. A clean polished surface will be more resistant to corrosion, and make the entire length of steel stronger overall.
Sharpening a knife can take a bit of practice, although there are products that do make easier work of it. Many companies produce stones set at predetermined angles so the blade only needs to be run between them. That is the easy way, but many people still use flat sharpening stones, both for their availability, and the control they offer. If you want to sharpen a knife on a whet stone, the key thing to remember is patience. A basic rundown of sharpening goes as follows.
Most whetstones will come in sets of two, featuring a rough stone, and a fine stone. The rough stone is used primarily to set the angle of the blade, as well as work out any nicks or chips in the edge. This is the stone to use first. Apply a lubricant to the surface, this can be water but mineral oil is a very popular choice, and set the flat of the blade at a 10 to 15 degree angle. Some kits will come with a plastic wedge to help guide the angle, but it isn't a requirement. The idea of keeping it in that zone will allow the blade to still be sharp and preform as needed, without the angle being so fine that it becomes more likely to chip or break. Patience is key. Try to make steady, consistent strokes, moving the entire length of the blade over the stone with the edge leading and grinding down towards the body of the blade. This makes it less likely to warp or roll the "truth" of the blade, being how consistent and straight the cutting edge is. After the edge is satisfactory, use the finer stone in much the same way. The difference isn't so much that the finer stone will put a finer edge on the knife, but rather will polish the section ground down by the rougher stone. This will remove small scratches and fissures in the knife surface that would develop into stress points, and harbor moisture for rust and corrosion.