Don’t have a sharpening kit? Don’t worry. Once you develop the technique, you be able to literally sharpen your knife on a rock—just as our ancestors did. Being able to sharpen your tools and blades on a stone is a vital skill, particularly in austere settings with limited supplies. I’d even go as far to say that being able to restore a keen edge to your knife is almost as important as carrying the knife in the first place. Here’s how to get a shaving-sharp edge with traditional stone whetting techniques.
To get started with real-stone sharpening, look for a fine-grained round stone in a local waterway. Select one that has a smooth section and seems similar in texture to your traditional sharpening stone.
Survey the damage on your blade to see just how dull your knife really is. Look for nicks in the edge, and try cutting a piece of paper or rope to test the edge. If the knife won’t cut well, or it has deep nicks in the edge, you have a lot of sharpening ahead of you.
Apply some water to the stone, and sharpen you knife with little circular strokes, equal numbers for each side of the blade. For a four-inch blade, I usually do about 30 little circles on each side. Try to match the edge angle of your knife as best as you can. Rinse your stone often while sharpening to keep its surface open and able to cut steel. Perform several rounds of sharpening on each side of the blade.
Once you feel you’ve sharpened the blade enough, remove any burrs and polish the edge by stropping the blade against a leather belt or log (or even your pants if you’re careful). Test the edge with a small carving or slicing task. If you’re not satisfied, sharpen and strop again.