My Field Guide to Flattening Diamond Plates & Nagura Stones: What Actually Works

When I first ventured into the realm of sharpening, I quickly discovered that a flat surface is the foundation of a well-honed blade. It’s like the bedrock of my sharpening practice. Over the years, I’ve experimented with various methods to keep my diamond plates and nagura stones flat. Spoiler alert: not all of them worked as advertised. Here’s my personal guide to what actually works based on numerous trials, errors, and a whole lot of sharpening.

Understanding the Tools

Before working through the flattening techniques, let’s quickly clarify what we’re working with.

• Diamond Plates: These are metal plates coated with diamond abrasives. They’re known for their long-lasting durability and effectiveness, but they can lose their flatness over time due to use.
• Nagura Stones: These small Japanese stones serve two primary purposes: they can be used to create a slurry on waterstones to enhance sharpening, and they help in flattening the surface of these stones.

Now, let’s talk about how to keep these tools flat.

Methods for Flattening Diamond Plates

I’ve tried a few different methods for flattening diamond plates. Here are my go-tos:

Method	Materials Needed	Time Required	Effectiveness
Wet/Dry Sandpaper	320, 600, 1200 grit sandpaper, flat surface	10-15 minutes	Highly effective
Diamond Plate on a Glass Surface	Glass plate, water	5-10 minutes	Moderately effective
Commercial Flattening Stone	Flattening stone	5-10 minutes	Very effective

Wet/Dry Sandpaper Method

This method has been a major upgrade for me. I take a piece of flat MDF or a granite slab and tape a sheet of 320 grit wet/dry sandpaper to it. After wetting the surface with a little water, I rub the diamond plate in a circular motion. This method gets the job done quickly and is surprisingly satisfying. I usually follow up with 600 and then 1200 grit to restore the surface to its original state.

Diamond Plate on a Glass Surface

This technique is straightforward. I use a flat piece of glass, apply a few drops of water, and rub the diamond plate against the glass. It’s easy and requires no additional materials. However, I find that it doesn’t quite flatten the plate as effectively as the sandpaper method.

Commercial Flattening Stone

If I’m in a hurry, I reach for my commercial flattening stone. This is designed specifically for flattening diamond plates and waterstones. It's effective, but it comes with a price tag of around $50-$100. For the serious hobbyist, it's worth the investment.

Flattening Nagura Stones

Nagura stones are a bit different, and I’ve had varying success with different methods.

Method	Materials Needed	Time Required	Effectiveness
Wet/Dry Sandpaper	320 grit sandpaper, flat surface	5 minutes	Highly effective
Using a Rough Waterstone	Coarse waterstone	5-10 minutes	Moderately effective
Diamond Plate	Diamond plate	2-5 minutes	Very effective

Wet/Dry Sandpaper Method Again

Yep, you guessed it! The wet/dry sandpaper method works wonders here too. I just lay the nagura stone on a flat surface covered in 320 grit sandpaper and rub it until it's flat. It’s quick and gives me the results I need.

Using a Rough Waterstone

This method involves rubbing the nagura stone against a coarse waterstone. While it can be effective, I find that it takes a bit longer and can create a mess. It’s useful in a pinch but not my first choice.

Diamond Plate

Lastly, using a diamond plate for flattening nagura stones is a solid option. It’s quick and effective, but I prefer to reserve my diamond plates for sharpening rather than flattening, as I want to prolong their life.

Final Thoughts

Flattening diamond plates and nagura stones doesn’t have to be a chore. With the right techniques, it can be a simple part of your sharpening routine. I’ve found that the wet/dry sandpaper method is consistently the most effective and economical option for me. In my workshop, these little rituals keep my tools in prime condition and my blades shaving sharp. I hope my field guide helps streamline your sharpening practice as much as it has mine!