What Stropping Does
At this point switch from a superfine hone-grit paper (1500 plus grit) to a leather strap, belt, or section of a belt, called a strop. The fine sandpaper hones, and the leather strops. Strop with the same back and forth motion, strop the blade’s edge against the leather. This action bends the now unseen burr back and forth against the leather and the burr finally breaks free. The edge thickness is now just paper thin or less. So “paper thin” doesn’t sound like the edge would bear up during use, being this thin, right on the very pinnacle of the blade’s edge—but it does.
With removal of the burr the edge acquires maximum sharpness and can be re-honed repeatedly without subjecting the blade to recurring sharpening cycles with lower grit sandpaper. This maintains the thin-and-sharp element of your blade.
Choosing A Strop
Make your strop from a strip of leather belt (10-inches long) glued to a bit of yardstick or lath material. Glue a strip of 800-1500 grit wet-n-dry sandpaper to the other side for a hone.
The same exact motion is used on the leather side of the strop stick. When the smith is “into” the motion it is similar to a continuous figure-8 movement. Most of the time the leather is enough to restore the blade’s edge without using the sandpaper side of the stick.
How To Strop
Stropping is a low-angle slap and slide motion. The leather actually sharpens the microstructure of the blade’s edge. It 1) bends the burr back to a sharp edge or 2) bends it back and forth till it breaks, like bending a wire coat hanger back-and-forth, revealing a new raw edge. Visualize a barber in an old-west, cowboy movie slappin’-n-slidin’ his straight razor on a big leather strop. Slap-n-slide your Frontier blade on the 800 to 1500 grit black W/D sandpaper 10 to 15 times then on the leather the same number of swipes. When your edge dulls you can often just strop with the leather, forgoing the hone altogether, in the restoration of a keen cutting edge.
After stropping, if your knife edge isn’t near razor sharp, go back to your wet-n-dry-sharpening action with the higher numbered sandpaper grits (400, 600, 800) then strop again.
Testing The Edge
Feel the edge with your thumb, perpendicular to the edge. Never run your thumb or fingers vertically up or down the blade. It will cut. With time you’ll be able to tell in an instant various level of sharpness with just your thumb. With time you will feel the burr and know the angle of any blade with just a touch of your thumb.
Another sharpness indicator is the use of an old leather belt or scrap of leather. Almost any “sharp” knife can cut a sheet of paper but stiff leather is the true challenge. First, use a knife of known sharpness. Cut a bit from the leather. Note the force needed to peel off a few pieces of leather. Use the same piece of leather on subsequent blade edges you sharpen in the future. By comparison, the quality of those blades’ sharpness can be gauged.