Oil or Water?
Everyone knows you need to lubricate your sharpening stone with water or oil, right? So the question is which one is better. Neither. The purpose of a sharpening stone is to grind the edge and remove metal. Oil reduces friction and makes the process much slower.
Supposedly oil helps float away metal particles that would otherwise clog the pores of the stone. You can do the same thing by wiping the stone with a damp cloth when youre done. Steve Bottorff reports that you can clean your Arkansas stones with paint thinner. Synthetic stones clean up with a scouring pad and abrasive cleanser.
According to Joe Talmadge, if you have already used oil on your Arkansas stone, youll probably need to keep using oil. But if you have a new Arkansas stone, a diamond stone or a synthetic stone, go ahead and use it without oil or water. It will work much better.
John Juranitch reports that in his companys work with meat processing plants they discovered that the metal filings suspended in the oil on a stone actually chip and abrade the edge. Although these chips were only visible through a microscope, the meatpackers readily noticed the difference between the knives sharpened on a dry stone and those sharpened on oiled stones.
Waterstones are another matter entirely. Both Japanese and synthetic waterstones require water in order to cut effectively. Japanese waterstones can be damaged if used dry and must be soaked thoroughly before use. Waterstones wear very quickly, revealing new layers of cutting abrasive as the swarf builds up and is washed away. Thats why they are so effective. There is always a new layer of sharp abrasive cutting away at the metal of your edge. By the way, swarf is one of those cool terms you get to toss around when you discuss sharpening. Swarf is the slurry of metal filings and stone grit that builds up as you sharpen. Throw that into your next cocktail party conversation and just watch the expressions of awe appear as people realize that you are a sharpening God.