A whetstone fixer, also known as a flattening stone or lapping plate, is an essential tool for maintaining the performance of your sharpening stones by restoring their flat, even surface, ensuring consistent and effective sharpening.
What is a Whetstone Fixer and Why is it Essential?
Over time, with repeated use, whetstones (especially waterstones and oilstones) tend to develop hollows or "dishing" in their center. This uneven surface makes it difficult to achieve a consistent sharpening angle, leading to poorly sharpened blades. A whetstone fixer works by abrading the surface of the dished whetstone, grinding away the high spots until the stone is perfectly flat again.
Why is flattening crucial?
- Consistent Angle: A flat stone allows you to maintain a precise and consistent sharpening angle across the entire length of your blade, which is vital for achieving a truly sharp edge.
- Optimal Performance: It restores the abrasive particles on the whetstone's surface, making it cut more effectively.
- Preventing Damage: It's also important to ensure that the corners of your whetstone are not left sharp or protruding after flattening. If the corners are sharp and stick out, they can easily scratch your knife's blade during the sharpening process. Therefore, you must grind down any sharp corners very thoroughly during flattening to create smooth edges that won't damage your knives.
Types of Whetstone Fixers
Whetstone fixers come in various forms, each with its own characteristics:
| Fixer Type | Description | Best For |
|---|---|---|
| Diamond Lapping Plate | A steel plate with industrial diamonds bonded to its surface. Extremely durable, provides a very flat and consistent abrasive surface. Available in various grits. | All types of whetstones, especially harder ones like ceramic or synthetic stones. Most common and recommended. |
| Silicon Carbide Stone | A coarse, abrasive stone made of silicon carbide. It sacrifices itself (wears down) to flatten the whetstone. Often more affordable. | Softer waterstones and oilstones. |
| Coarse Sandpaper on Glass | A DIY method where coarse grit sandpaper (e.g., 200-400 grit wet/dry) is adhered to a perfectly flat surface like a thick piece of glass or granite. | Occasional flattening, very soft stones. Less precise than dedicated fixers. |
| Concrete Block | A very coarse, inexpensive option. Can work but may not provide the same level of flatness or consistency as dedicated tools. | Large, very dished stones or emergency situations. Requires careful technique. |
Step-by-Step Guide to Flattening Your Whetstone
Using a whetstone fixer is a straightforward process that will significantly improve your sharpening results.
- Preparation:
- Soak Your Whetstone: If you are using a waterstone, ensure it is fully saturated by soaking it in water until no more bubbles appear. For oilstones, lightly coat the surface with sharpening oil.
- Clean the Fixer: Rinse your whetstone fixer to remove any debris from previous uses.
- Stabilize the Whetstone:
- Place your dished whetstone on a stable, non-slip surface, such as a rubber mat or a wet towel, to prevent it from moving during the flattening process.
- Apply Water (or Oil):
- Pour a generous amount of water (or oil for oilstones) onto the surface of the whetstone. This creates a slurry that helps with abrasion and lubrication. For diamond plates, just keeping the surface wet is usually sufficient.
- Begin Flattening with Consistent Motion:
- Place the whetstone fixer directly on top of the dished whetstone.
- Apply even, moderate pressure and begin moving the fixer across the whetstone's surface. Use various patterns to ensure even flattening:
- Figure-Eight Motion: This helps to distribute pressure evenly and ensures you're abrading all parts of the stone.
- Circular Motions: Small, overlapping circles across the surface.
- Crosshatch Pattern: Alternating strokes diagonally and straight across the stone.
- Concentrate on the areas that are higher (usually the edges of a dished stone), applying slightly more pressure to these spots if necessary.
- Monitor Progress:
- Periodically lift the fixer and rinse both surfaces. Check the whetstone for flatness. You'll typically see a uniform, dull appearance across the entire stone when it's flat. A good way to check is to use a straight edge (like a ruler) across the stone to look for any remaining gaps or hollows.
- Continue the flattening process until the entire surface is uniformly abraded and perfectly flat.
- Rinse and Refine Corners:
- Once your whetstone is flat, thoroughly rinse both the whetstone and the fixer to remove the slurry and abrasive particles.
- Crucial Step for Blade Protection: Carefully inspect the edges and corners of your newly flattened whetstone. If they are still sharp or protrude, they can easily scratch your knife's blade. Use the fixer (or a dedicated deburring stone/sandpaper) to grind down these sharp corners very well, creating a slight chamfer or rounded edge. This ensures your knives glide smoothly over the stone without incurring accidental scratches.
Tips for Optimal Whetstone Flattening
- Regularity is Key: Flatten your whetstones regularly, especially finer grit stones, as they tend to dish more quickly.
- Even Pressure: Maintain consistent, even pressure across the fixer to avoid creating new uneven spots.
- Keep it Wet: Always keep the surfaces well-lubricated with water or oil during the process.
- Use the Right Grit: While most diamond plates work for all whetstones, using a coarser fixer for coarser whetstones and a finer fixer for very fine finishing stones can sometimes yield better results.
Maintaining Your Whetstone Fixer
- Rinse After Use: Always rinse your whetstone fixer thoroughly after each use to remove abrasive slurry and prevent clogging, especially with diamond plates.
- Store Properly: Store your fixer flat and dry to prevent warping (for silicon carbide stones) or damage to the diamond surface.
- Check for Wear: While diamond plates are very durable, silicon carbide stones will wear down over time and eventually need replacement.
By regularly maintaining your whetstones with a fixer, you ensure they perform at their best, leading to consistently sharper edges and extending the life of your sharpening tools.
