Dull Tools Dangerous : Staying on Edge With Sharpening Stone

Early American Indians quarried natural sharpening stones to use as spear and arrow tips. In 1823, Isaac Pike of Littleton, N. H., began to handcraft stones for use in sharpening tools.

Today, natural abrasive stones are quarried mostly in the Ouachita Mountains of Arkansas, and are said to produce the finest precision edge possible. But they are recommended for final finishing after prior sharpening with man-made stones, the kind most people use.

Sharp tools are safer than dull tools. Many failures and possible injury result from a dull cutting edge because the tool can no longer function as it was intended.

A dull kitchen knife can turn a skillful carver into a hacker. Dull scissors, garden edgers, chisels and pruning shears, too, can be difficult to use and basically are unsafe.

For efficient sharpening, all stones, man-made or natural, should be lubricated with light oil to float away metal and abrasive dust that otherwise would clog and neutralize the stones. Some man-made stones are prefilled at the factory with lubricating oil.

These stones can eliminate pre-soaking, which can take several days, but even these should be lubricated with a drop or two of oil each time they are used.

Work Against Stone

The most common stone is the bench stone, which is flat on both sides. This is for straight-edged items such as knives, chisels and plane irons.

Generally, the bench stone you select should be at least one inch wider than the widest tool you will be sharpening. It also should be long enough to take an effective stroke. In most instances, you should sharpen against the edge; that is, work against the stone.

We asked an expert on the subject, Bruce Anderson of Norton Co. of Worcester, Mass., a maker of abrasive products, to give us some how-to tips to pass along to the do-it-yourselfer. He came up with these:

Tool Techniques

--Carving knife: Hold stone steady in one hand at a 15-20 degree angle, and with the other draw cutting edge of knife in long sweeping motions against the stone diagonally from handle to tip. Stone one side of blade, then the other, in alternate strokes.

--Scissors: Grasp scissors at middle and place blade on coarse stone at slight diagonal. Tip blade up so cutting edge is flat on stone. Draw blade diagonally across stone several times. Repeat with other blade. Repeat steps on fine stone.

--Sod cutters: Clamp handle in a vise. Apply stone at an angle parallel with bevel edge. Stroke in small circular motions around complete arc of the edge.

--Axes: Hold axe on bench or table with cutting edge projecting over the side. Stroke with circular motions. Coarse first, then fine.

--Wood chisels: Place chisel on coarse stone with beveled edge raised slightly. Stroke in long “Figure 8” motions. Occasionally rub non-bevel side lightly to remove burrs. Repeat on fine stone.

--Fish hooks: This specially designed stone has three grooved sides and a flat side. Sharpening tips and barbs is done by drawing them back and forth in the grooves.

(Do-it-yourselfers will find plenty of helpful data in Andy Lang’s handbook, “Practical Home Repairs,” which can be obtained by sending $2 to this paper at Box 5, Teaneck, NJ 07666.)