A grinder cuts like scissors: the knife's edges shear against the plate. When either goes dull or out of flat, meat smears instead of cutting. You can sharpen both at home by lapping them on a flat surface.
How to lap a knife and plate
- Tape wet-or-dry sandpaper (around 220 grit, then 400) to a flat surface such as a sheet of glass, or use a flat sharpening stone.
- Place the plate face down and move it in figure-eights with even pressure until the whole face is bright and flat.
- Do the same with the knife's cutting face, keeping all the blades flat on the paper.
- Wash, dry and oil.
When to replace
If the plate is deeply scored or the knife is chipped, replace them. Standard-size plates and knives are inexpensive for most #8 and #12 grinders. Replace or lap the knife and plate as a pair, since they wear together.
Built-in sharpeners
The Weston Pro Series #8 has a built-in knife sharpener.
