Step 4 of the process
Coarse to fine
Each finer stone replaces the scratches of the last with smaller ones. Start on the coarsest grit the edge needs, keep the same angle with less pressure on every stone, and finish with light alternating strokes that take the burr off.
- Chips or a new angle
- start coarse, about 240 to 400 grit
- Normal sharpening
- about 1000 grit
Grits work as a relay. The first stone shapes the edge and leaves scratches; every stone after it only has to remove the scratches of the one before. That is why the order is always coarse to fine, and why the starting grit depends on the state of the edge: a chipped edge starts coarse, a merely dull one starts on the medium stone, and a knife that still cuts may only need the fine stone.
On each new stone keep the same angle and use less pressure. It takes far fewer strokes than the first stone did to bring up a small burr again, which tells you the finer scratches have reached the apex. The grit progression helper gives the order for the stones you own, and the grit chart shows how water stone, diamond and oil stone grits line up in microns.
The last strokes on the last stone remove the burr. Make single light strokes, alternating sides. The burr gets smaller with each pair until a fingertip finds nothing on either side. You do not need every grit: an edge finished at about 1000 grit already cuts food well, and finer stones add polish and a cleaner cut, not basic sharpness.
Ready to move on when: The scratch pattern is even from heel to tip and no burr can be felt from either side.
Common mistakes at this stage
- Going straight to a fine stone with an edge that needed the coarse one.
- Pressing as hard on the finishing stone as on the first.
- Carrying coarse grit onto a fine stone on an unrinsed blade.