Always flatten a whetstone wet. Using water (or honing oil for oil stones) acts as a lubricant, prevents the stone from clogging with ground metal and abrasive particles (swarf), and keeps the stone from glazing over.
Waterstones and oilstones wear at greatly different rates: The softer of the two, waterstones, dish out faster and need to be flattened more often. We recommend flattening them at the beginning of every sharpening session-it's a 15-second job in most cases. Flatten oilstones about every 10 sessions.
To flatten a whetstone, draw a grid pattern on the stone’s surface with a pencil. Submerge both the whetstone and your flattening tool in water. Rub the two surfaces together in a figure-eight or circular motion using even pressure until all pencil marks disappear.
How to Flatten a Water stone
Diamond stones don't need to be flattened, and oil stones rarely need flattening; however, ceramic and water stones require regular flattening. Many of us flatten our stones after each sharpening session so they are ready to go next time around.
When using a whetstone, you should use both pushing and pulling strokes for the most effective sharpening session.
The Atoma plates come in four different grits - #140, #400, #600 and #1200. We have no hesitation in recommending the #400 as our preferred grit for flattening, closely followed by the #600. The coarser the grit in the Atomas, the longer lasting they'll be as stone flattening plates.
Diamond stones can be used without any lubrication, but it's generally recommended to use either water (make sure to clean and dry it afterwards), a light machine oil or WD40.
Other tools, like kitchen knives, can still be sharpened effectively on a stone that isn't perfectly flat. You'll get better results on a flat stone, but you can still improve your edge if the stone is slightly dished. That said, frequent flattening is also beneficial to maximizing the lifespan of your stones.
Yes, you can use WD-40 as a lubricant on oil-based sharpening stones, but it is not the best option. Because WD-40 is very thin, it fails to effectively float away metal shavings (swarf), which can clog your stone.
Here are the most common mistakes and proven ways to avoid them:
Diamond stones are very low maintenance. They don't need flattening, the surface doesn't need prepping before use and they can even be used dry. That said, we recommend using a cutting fluid, such as water, to rinse away the swarf (metal particles) left behind during sharpening.
Cutting boards made of glass, granite, ceramic, or your dinner plate may look stylish or convenient, but they are the fastest way to destroy a knife's edge. These surfaces are harder than your knife's steel. So every time your blade contacts them, it suffers microscopic edge deformation, chipping, or even rolling.
Hapstone oil is designed for use with many different types of sharpening stones. You can use them for diamond, CBN, natural and synthetic abrasives. Thus Hapstone oil will become indispensable during sharpening.
Step-by-Step Instructions:
Mild Dish Soap: Yes, Dawn dish soap works wonders–but any “grease cutting” dish soap will do. Ammonia: Only use if all the gems in your ring are diamond or a hard, faceted stone (like a sapphire) Warm Water: Not too hot, not too cold—you're cleaning a ring, not making tea.
For routine kitchen and pocket knives, you should generally flatten your whetstone every 3 to 6 months, or sooner if it becomes visibly "dished" (concave in the middle). Professional chefs and woodworkers often flatten before every sharpening session for maximum consistency.
Gordon Ramsay primarily uses a traditional honing steel (or sharpening rod) to maintain knife edges before use, emphasizing safety and consistent 45° angles. While he often uses professional whetstones for deep sharpening, modern demonstrations (and fan-used products) have shown the Tumbler Rolling Sharpener to be highly effective for achieving a razor-sharp edge on his knives.
We usually leave this job to our partners), we suggest getting combination whetstone, something between 1000 and 6000 grit. Like this King's combination whetstone. These two stones and an inexpensive flattener will carry you a very long way. Add other stones or stropping supplies in the future as you learn.
Pull-through sharpeners are not universally "bad," but they are generally discouraged for high-quality or expensive knives. They offer quick, convenient edge maintenance but are highly aggressive, removing excess metal and often leaving a fragile, jagged edge.
Whether you sharpen both sides of a knife depends entirely on the type of knife you have.
Sharpening a knife effectively relies on maintaining a consistent angle (usually 15 to 20 degrees), applying steady pressure (about 2-4 lbs), and establishing a wire edge or "burr". The most precise way to restore a razor-sharp, custom edge is by using a flat whetstone.