Using a bench stone is a fundamental way to sharpen knives and tools, restoring a keen edge through abrasive friction. While the general technique involves specific steps, specialized tools or methods might incorporate additional features. As noted in the provided reference, a technique can involve activating features like "pivot response" to follow the blade's curve while sharpening, making a specific number of "passes per side," such as five, until a "bur" is raised.
Here's a breakdown of the general process for using a bench stone, incorporating the concept of passes and bur formation mentioned in the reference:
Understanding Bench Stones and Grits
Bench stones come in various types (water stones, oil stones, diamond stones) and grits. Grits refer to the coarseness of the abrasive material – lower numbers are coarser for repairing damage and setting an edge, while higher numbers are finer for refining and polishing the edge.
Preparing Your Bench Stone
Before you begin sharpening, proper preparation is crucial:
- Choose the Right Stone: Select a grit suitable for the task (coarse for dull edges, medium for maintenance, fine for polishing).
- Lubrication: Most stones require lubrication. Water stones use water, oil stones use honing oil. Diamond stones can be used dry or with water. Lubrication helps float away the metal particles and prevents the stone from clogging.
- Secure the Stone: Place the stone on a non-slip surface or in a holder to prevent it from moving during sharpening.
Finding and Maintaining the Angle
Maintaining a consistent angle is the most critical part of sharpening. The exact angle depends on the knife's intended use (e.g., kitchen knives often use 15-20 degrees per side, outdoor knives 20-25 degrees).
- Angle Guides: Some systems, like the one potentially referenced with "pivot response," may offer built-in angle guidance or features to help maintain the angle along the blade's curve.
- Freehand: Without guides, you need to hold the blade at the desired angle relative to the stone's surface. Practice is key to developing a feel for the correct angle.
The Sharpening Passes
Sharpening involves moving the blade across the stone at the chosen angle.
- Direction: You can push the edge into the stone (leading edge stroke) or pull the spine first across the stone (trailing edge stroke). Many prefer trailing edge strokes as they are less likely to dig the edge into the stone.
- Coverage: Use the full length of the stone with each pass, moving the blade sideways to sharpen the entire edge from heel to tip.
- Making Passes: As mentioned in the reference, you make "passes per side." This means completing a stroke or set of strokes on one side of the blade before switching to the other.
- Raising a Bur: The goal of using a coarse or medium stone is often to create a "bur." A bur is a tiny wire edge of metal that forms on the opposite side of the edge you are sharpening. You can feel it by lightly running your thumb across the edge (never along it!).
| Sharpening Action | Description | Purpose |
|---|---|---|
| Set Angle | Hold the blade at the correct angle relative to the stone surface. | Ensures the bevel is ground correctly. |
| Make Passes | Move the blade across the stone, covering the entire edge. | Removes material to create a new edge. |
| Activate Pivot Response | Specific technique noted in reference: Use a tool feature to follow the blade curve. | Helps maintain the angle on curved blades. |
| Sharpen Per Side | Work on one side of the blade before switching to the other. | Develops the bevel evenly on both sides. |
| Raise a Bur | Continue passes until a thin wire edge forms on the opposite side. | Indicates the edge has been ground thin enough. |
Alternating Sides and Refining
Once a bur is raised along the entire edge on one side, flip the blade and sharpen the other side until a bur is raised there as well (or the bur flips back to the original side).
- Reduce Passes: As you move to finer grits, reduce the number of passes per side (e.g., from five passes down to two or three). The reference mentions making "five passes per side until I've raised the bur" likely referring to the initial stages on a coarser grit.
- Progress Through Grits: Move from your coarse/medium stone to finer grits to remove the bur and refine the edge. With finer stones, you use less pressure.
Finishing
After using the finest stone, the edge should be very sharp. You can further refine it by stropping on leather or a ceramic rod.
By combining proper technique, understanding grits, and paying attention to angle and bur formation, you can effectively use a bench stone to achieve a sharp edge.
