Spyderco Fine Ceramic Stone

[hein31]

I don't have the Norton India, but i have several artificial arkansas stones by a german manufacturer named LAPPORT. On their stock list, they rate it at hardness "R", which is almost at the top.

They produce "Indiga" stones, and the name is obviously a hint on what to expext, they are rated "O" which is still hard, but a full hardness level lower than their "Record Arkansas". And if i compare the Lapport Arkansas to the Spyderco, it is still quite manageable. It takes a while to flatten them, but they are only a little harder than an average siliconcarbide stone. Since these artificial Arkansas stones are still a bit porous, it is not wise to lap them with SiC grain smaller then F220 because smaller grains will clogg the pores and make the white stone grey, quite a mess to clean without resurfacing it completely.

The Spyderco has no pores, it is fully compact. So imagine what it does for hardness.

 

[David Martin]

I cannot speak toward an 'artificial' Arkansas stone. Having no experience. Here in America Arkansas stones are a natural stone, not man made.
Thus, are quarried from the mountains around Hot Springs Arkansas. Of these, I have all the grits. They are not nearly as hard as the man made India and SiC stones. Knoops rated their hardness at 2500-2600 SiC, 2100-2000 for India, 2150 Ceramic and Black Arkansas at 1800.
Different elements can be added to ceramic to cause it to come out harder and cut better, like zirconium, silicon nitrite, glass, ect.. So, being unsure what ceramic we are referencing with the Spyderco stone, it is known to be aluminum oxide and more dense than Norton's India.
I recall reading Sal Glasser's statements they had difficulty getting it just right during the manufacturing process. I have read that bone china and
ceramic cups are fired at 3000*. Quite high when compared to knife steel. DM

 

[hein31]

I cannot speak toward an 'artificial' Arkansas stone. Having no experience. Here in America Arkansas stones are a natural stone, not man made.
...

See it as a tribute, that a german manufacturer wants to benefit from the fame of a known stone like the Arkansas. I have no idea when they were started to be produced, but i'm shure back then the names of famous american tools sounded to the natives here like "the magical katana".

Thus, are quarried from the mountains around Hot Springs Arkansas. Of these, I have all the grits. They are not nearly as hard as the man made India and SiC stones. Knoops rated their hardness at 2500-2600 SiC, 2100-2000 for India, 2150 Ceramic and Black Arkansas at 1800.
Different elements can be added to ceramic to cause it to come out harder and cut better, like zirconium, silicon nitrite, glass, ect.. So, being unsure what ceramic we are referencing with the Spyderco stone, it is known to be aluminum oxide and more dense than Norton's India.
I recall reading Sal Glasser's statements they had difficulty getting it just right during the manufacturing process. I have read that bone china and
ceramic cups are fired at 3000*. Quite high when compared to knife steel. DM

Be assured, anything expensive would have meant a prohibitive price tag, and these stones are quite affordable, think half the price for a japanese 1K stone. The artificial arkansas they produce contains mostly standard corundum, Al²O³. The binder should be some standard silica binder for hard sintered ceramic stones, nothing fancy.

The term "hardness" for stones doesn't necessarily refer to the particles, but more to the toughness of the binding. The more binder is added, the tougher the final stone is.

The chinese red stones "3000 grid oilstone" can be compared to the spyderco, flattening is surprisingly hard, but not comparable to the Spydercos. And as a whetstone, i don't like them. Mostly corundum with too much binder. Not the most effective stone. But good as a substrate if you use the cheap TAIDEAs as nagura...