This illustrates the stages a knife or other blade goes through during the sharpening process.
MOTHER EARTH NEWS STAFF
Given time, and given the aesthetic sensibilities of a hunger-crazed ape, you can carve out a joint of meat with a wooden shovel. But when you cook for joy and art, you need a tool that will afford the niceties of clean cut and proper thickness. You need a blade as sharp as Occam's razor.
Sharpening a Knife
Sharpening a blade is greatly a function of retaining one angle to form a clean edge, without rounding or jogging. The ideal sharpening angle differs with the steel, but 15°-20° is a good range for kitchen cutlery. • A dull knife begins on the coarse India stone. This shapes more than sharpens; it forms the angle of the blade but leaves it gouged and rough with a ragged edge. The stone is well-oiled with petroleum, heavy mineral, or neat's foot oil. The oil floats metal dust away from the cutting surface, leaving it free to cut again. The oil should be wiped away and replaced at intervals. The main stroke is made into the blade, and the back stroke draws it along the stone with a very light pressure. • The smooth India stone follows the angle shaped on the coarser grit, honing it more evenly. The smoother the grit, the more critical the oiling and wiping, since a shallower surface clogs more quickly. • A blade's wear begins at its imperfections. The smoother the edge, the sharper and harder it will be. Polishing the edge on a Hard Arkansas stone (for knives, chisels, plane irons and other tools) or a Steel (mostly for kitchen knives) brings it to a smooth, even sharpness. • Steel is malleable and ductile. As the underside of the blade is being cut away on the stone, the very edge of the top is being draw out in a thin, folding sheet called a feather edge that rolls over and dulls itself. The feather edge is loosened by drawing the blade back along the stone lightly—on one side, then the other. • A note on steels: early stainless alloys were very ductile and the feather edge was problematic. Carbon steel was preferable, but more recent alloys have overcome earlier deficiencies and there is no reason not to enjoy the convenience of rust-free blades. When the feather-edge breaks away, it leaves a microscopically dull edge. Stropping draws out the edge sharp again. Stropping is traditionally done on ox-leather, or treated canvas, though some carpenters use some soft wood, draw one side along it, then the other.
A Kitchen Armory
"If you want to do a mechanics job, you got to have a mechanic's tools" - Hudson Jayne