How to Sharpen a Knife with a Whetstone

A whetstone (not ‘wetstone’ whet is an old term that meant ‘sharpen’) is a rectangular block that is similar to a sanding stone. First, whetstones usually have to be soaked in water for about 5 to 10 minutes until all of the bubbles are done coming out of it. This makes sure that there is no contamination that will make sharpening your knife harder to do. Of course, always read the manufacturer’s recommendation for your particular whetstone. Some whetstones require you to add a small amount of mineral oil instead to get it ready for sharpening.

Your whetstone may have a coarse side and a finer side. You would start with the course side to get the blade to the proper shape then switch to the finer side to finish up sharpening the knife to a more refined edge. If you take care of your knives well by sharpening them every few months and honing them every two to four times of use then you should be able to just ‘touch-up’ the knife and go straight to the finer side of the whetstone.

You sharpen the knife by sliding the blade across the whetstone at a 20-degree angle against it on both sides of the blade evenly.

If you are having trouble keeping the 20-degree angle while sharpening your knife you can use a knife sharpening angle guide. A sharpening guide is a small tool that is placed underneath the knife so that you can keep the knife at the same angle while you drag it across the whetstone.

A 20-degree angle is good for most knives. If you are sharpening a fillet knife or a boning knife then you would hold the knife at a 15-degree angle and if you have a tactical knife then you would hold it at about a 30-degree angle.

Move the knife edge down the stone in a direction away from you in a way so that you go over the whole blade in one single motion.

When moving the knife along the whetstone be sure to use the same even pressure along the entire length of the blade to ensure a more uniform sharpening. Putting too much pressure while doing this will ruin both the stone and the knife blade by causing flat spots on the blade, uneven edges on the blade, and ruin the consistency of the whetstone.

Be sure to alternate between both sides of the blade while you are sharpening to keep everything even. You can do about 5 strokes on one side then 5 strokes on the other side. Never do all the strokes on one side then do all the strokes on the other side. This can lead to the blade becoming uneven.

Repeat this procedure about a dozen times on both sides of the blade as you sharpen. Always go in the same direction instead of going back and forth.

Once this is done repeat the procedure on the finer side of the whetstone doing the exact same thing.

If the whetstone seems to be clogging up or getting dry just rinse the stone with some rubber and wipe off any residue.

After you have your knife sharpened you can test the sharpness of a knife by slicing a tomato. If you can easily slice through the skin of a tomato without having to use any pressure then it is sharp.