How (and Why) to Flatten Your Whetstones with a Truing Stone
Around here we know just how fun sharpening knives is. The process of taking a lacklustre edge and polishing it up to a glorious mirror of steel is easily one of the most satisfying activities. Not only that, but when you’re done, you’ve got sharp knives, ready to take on anything! Sharpening using a whetstone takes a little bit of practise and finesse, but it’s a skill I strongly believe nearly anyone can pick up with a little bit of practise and patience. However, there’s one step that a lot of people miss. It’s easy to forget to take care of your stones. Aside from the really obvious stuff (don’t dry them in direct sunlight, don’t expose them to sub-zero temperatures, don’t drop them), keeping your stone flat (or true, if you’re fancy like us) is paramount!
If you’re trying to sharpen a knife on a dished out or wonky stone, you’re going to get poor results - plain and simple. This goes doubly true if you’re thinning out the primary bevel on your blade. So how does this happen, and how do you prevent it? You’ll need a truing stone!
A truing stone is a stone for your stones. Yep, that’s not a typo. You need to use a stone on your stone. But a truing stone isn’t just any stone. Most truing stones are made using a different type of abrasive that eats away at ceramic and natural sharpening stones quickly. They often have deep ridges on the action side to help facilitate the flow of ceramic and water off of the surface of the stone. Take a look!
Funky looking, right? So how does it work? When you sharpen a knife on a whetstone, it’s impossible to use the stone’s surface completely evenly. Try as you might, you’re going to wear down specific areas of the whetstone faster than others. Generally, the top, bottom, and corners of the whetstone are going to get left out, while the middle of the stone gets worn away more quickly. After every couple of knives, it’s a good idea to grab your truing stone and go to town. Remember to pour lots of water on the surface of the stone you’re truing before you do so, or soak it if required.
This isn’t the only tool that one can use to true their whetstone - I actually prefer using an Atoma Diamond Plate over a ceramic truing stone because they tend to cut the whetstone more quickly, meaning I need to spend less time flattening. They're also more flat. The cheap & cheerful Knifewear truing stone isn't perfectly flat, and that's okay! If you use it frequently, it'll flatten out as you use it and your stones will be quick to true. If you true less often or you just want the best, a diamond plate is the way to go.
When you sharpen as many knives as I do on a day to day basis, having this diamond is a HUGE time saver! It should definitely be something to look into if you sharpen lots of knives on the regular.
ANYWAY. Let’s get started!
How to Flatten a Whetstone with a Truing Stone
Step 1: Draw a grid on your whetstone using a pencil.
This is super important. This grid is going to act as a visual guide and tell us when the stone is totally flat. It should look like this:
This is where the fun begins! In a circular motion, wear down your sharpening stone. Draw the circles with your truing stone in such a way that it hangs over all the edges of the stone as you pass over them, ensuring it gets good contact with every part of the whetstone.
It should become clear which parts of the whetstone your truing stone has been wearing away. Any portion of the pencil grid that is now worn off is higher than the portion where the grid remains.
Splash on more water if necessary, and continue to work those even circles until the pencil lines are completely gone. Resist the urge to focus in on the high areas - it’s very important that you work evenly! When the grid is totally gone…
Step 4: Bevel the edges of the stone.
Nice! Your stone is perfectly flat! But it’s always nice to grind off those sharp and dangerous edges of your stone so you don’t accidentally snag your poor tender knuckles on them while sharpening the next knife. Place the truing stone at a 45 degree angle along the edge of the stone and grind off those sharp corners in an elliptical movement.
Don’t overdo it! You usually only need to draw about a half dozen ovals before the corner is gone, anything more will just wear down your stone unnecessarily.
There you have it. All done.
I recommend truing your low or medium grit (220 - 2000) stones after every two to four knives, and your fine harder stone (3000 and up) every five to ten knives. If you wait too long between truing, you can really get into some rough situations. Truing doesn’t take long if you do it frequently, but if it gets out of control, it can take up to 20 to 30 minutes to get a stone back into shape. Remember — flat stones are happy stones. Happy sharpening!
Truing Stone FAQs
- Does my truing stone need to perfectly flat? Nope! Unless it does. For regular knife sharpening and thinning, mostly flat is good enough. If you sharpen single-bevel knives, straight razors, or sharpen professionally, get a diamond plate.
- Can I use my coarse truing stone on fine grit stones? Yes! A regular truing stone works well on any grit of stone, just be sure to rinse the stone well after truing to remove any rough grit left over. I find diamond plates scratch up fine stones a little, so I follow up with a nagura stone to smooth them out.
- Will my truing stone wear out? Eventually, but it takes AGES. if you wear it down enough for the grooves to disappear, replace it. Diamond plates wear out when all of the diamond layer wears down, and this layer can be peeled off and replaced.
- Do I need to clean a truing stone? Sort of, but don't stress about it. Give it a good rinse and a quick scrub with a sharpening rag, and you'll be good to go!
- My fine grit stone is all black from sharpening, should I true it? You can, but fine stones don't need truing with every use. I use a nagura stone to remove a very fine layer from the stone, so it continues to work well and doesn't wear out quickly.
