Gesshin 800 Vitrified Diamond Stone

The diamond 300A stone is a 300 grit diamond stone.  Unlike diamond plates, these stones are constructed in a manner more similar to normal waterstones.  The top ~5mm of the stone is composed of a hard binding agent with diamond abrasive mixed in.  This is then attached to a taller base, such that the whole item together is about the same size as many of the other stones we sell.  Unlike some diamond stones that use metal or aluminum bases, this base is a lightweight, water resistant plastic, which I have found to be lighter and more convenient to use and care for than other bases.

With regard to the stone, we have spent a significant amount of time working with the maker to find the right balance of cutting power, tactile feedback, and resistance to dishing.  Coarse stones tend to get the brunt of work when repairing knives or trying to get through sharpening more quickly.  This stone is rather fast cutting, though it is not particularly muddy.  I use this stone to remove deep 150 grit scratches, which it does with ease, rather quickly.  The scratch pattern it leaves is very consistent and even, and, again, unlike diamond plates with the abrasives plated onto the surface, these stones leave scratches with a depth more similar to regular sharpening stones.  Thanks to their diamond abrasive, they work well on all steel types, including some of the most hard and wear resistant steel.  They can even be used to sharpen ceramic knives.  As the binding agent is not porous, these stones are true splash and go stones.

This diamond stone does dish a bit faster than some other diamond stones, which is why we have it in a thicker stock, and also include a special flattening device for flattening these types of stones.  That being said, it still dishes very slowly, and after over a year of heavy use, I have worn through less than 20% of the stone.  As a comparison, in the same time frame, I was able to wear completely through a different type of diamond stone, and multiple ceramic and resinoid-based stones.  When using the flattening stone, work the high spots down by rubbing those areas in a circular motion.

The Gesshin™ 220 Grit Sharpening Stone is a VERY coarse stone for major repairs, thinning, and removing large chips.  I have been using this stone for about 2 years and have finally decided to add it to our Gesshin lineup.  It works well on all types of steel I have tested it on, from simple carbon steels to the most high-tech and hard stainless steels.  It cuts very quickly and has great feeling and feedback.  It is a bit softer, so it can dish, but relative to its cutting speed, I have not seen this as much of a problem.  It is possible to jump to a middle grit stone from this stone, but I recommend using something like the Gesshin 400 following this.  This stone needs to be soaked at least 15 minutes before use.  I leave mine in water all of the time, so it is ready to go whenever I need it.  If you do leave your stone in water, please change the water regularly.  When drying out this stone or any others, do so out of the sunlight in a well-ventilated area.

The Gesshin™ 320 Grit Sharpening Stone is a very different kind of stone from most that I have seen on the market.  These stones are entirely splash and go... they require no soak whatsoever.  Just a splash of water and they are ready to go.  In fact, its very important that these stones are not soaked, as they will fall apart.  You will notice that the stones are lacquered on all sides but one.  The non-lacquered surface is usable surface (the opposite side from where our logo is).  Because of the way these stones are bound together, they are a bit more brittle than the other stones we have in stock.  It is very important to round the corners of the stone before and after flattening to prevent chipping along the edges.  Initially, the stone surface will show some small pock marks and swirly textures.  It is not necessary to completely flatten this all out, though it will eventially flatten out over time.

We highly recommend flattening the stone before initial use.  The top layer of the stone needs to be removed for peak performance.  This can be done by either flattening or using the stone until that layer is gone.

This is an excellent coarse stone.  Unlike many coarse stones, it dones't feel harsh during use.  It has a very smooth feel, and cuts rather quickly.  It is also slower dishing than most other coarse stones we carry, including our Gesshin 400, 400s, and 600.  The alumina based abrasive works well on a wide variety of steels.  The surface of the stone will look as if it is loading up while sharpening (i.e. it becomes blackish), but as you add water, you will notice that the stone does not load as it cuts.