Thread: Dose this make sense to you?

Originally Posted by holli4pirating

I don't agree with the first part of that. If a 12k abrasive is buried deep in binder, such that only so much of it is exposed, it could cut as shallow as a 20k abrasive. If the finish is based on depth of scratches, they could be the same. Might take more honing, as, in theory, 12k abrasive would be more spread out than the 20k abrasive, so it would take more time to eliminate the scratches from the previous hone. And you'd have to avoid burnishing on steel that is removed and is stuck in (what would have to be) slow wearing binder. Or the grit itself could break down, etc etc.

I do agree with the idea that assigning grit ratings only provides a rough guide, and the roughness gets more rough as the abrasive becomes finer. (ha, rough/fine)

How can we even assign a natural stone a grit rating? What gauge or process would determine that grit rating? Unless we manufacture that stone/hone, which in this case the stone was pulled from the ground(a natural), we cannot be accurate. We can give our best guess based on experience with man-made stone, right,, so are our guesses accurate enough to tell the difference between a 12K or is it really a 15 or 16K.

How deep is the diamond abrasive on a plate(DMT) a 600 versus a 1200? Hard to tell by feel and hard to decipher by scope. Maybe it isn't depth , but quantity & size.

Different steels can produce different scratch patterns with the same stone.

There was an interesting study done on jnat slurry.

StewieS.

https://scienceofsharp.wordpress.com...ry-break-down/

https://scienceofsharp.wordpress.com...slurry-part-2/

Think of it like this....

Picture a pencil point neatly sharpened. That is a single point of contact, a single "grit" if you will. That point is sharp and spikey, and will cut deep.

Now think of that same point worn all the way down. Its now almost flat, perhaps even semi spherical. It will hardly cut at all. Still a single "grit" but now that one grit is not scratching as deep.

Originally Posted by Magpie

Think of it like this....

Picture a pencil point neatly sharpened. That is a single point of contact, a single "grit" if you will. That point is sharp and spikey, and will cut deep.

Now think of that same point worn all the way down. Its now almost flat, perhaps even semi spherical. It will hardly cut at all. Still a single "grit" but now that one grit is not scratching as deep.

Take that sharpened pencil point & that worn down pencil point and neither one will cut glass.

Assigning hard grit ratings to naturals is folly. They often change in character even as you periodically lap into them. They either progress your edge from whatever came before or knock it back...

I suspect it's the same or similar material as the brown apache black gilas. Never had that but I have a green gila. The problem I have with all of them is they are expensive and god forbid you need liquidity back for whatever reason, if a person sees that for 275 and a thuri with a label for 275usd they are buying the thuri every time...

Originally Posted by Hirlau

Take that sharpened pencil point & that worn down pencil point and neither one will cut glass.

but stick them in your eye and everything will become clear

Hopefully clearer than post # 13,,,,,,

There are all kinds of natural stones. Some are made of homogeneous material making them easier to classify however the stone mined 50 feet away might have a slightly different composition. Stones that contain minerals that function as the "active ingredient" in honing are more difficult. You have to factor in the binding material or matrix and then if the active material is say garnet the type and size of the xtls and how they are released and the type of xtl has to be considered. Garnets are rarely just spherical blobs in the matrix. The are usually dodecahedrons though there can be others and depending on what part of the xtl get the stress the hardness can vary from facet to facet and the way they breakdown will vary too. Of course as with the other types of rock the material can vary from specimen to specimen.

Originally Posted by thebigspendur

There are all kinds of natural stones. Some are made of homogeneous material making them easier to classify however the stone mined 50 feet away might have a slightly different composition. Stones that contain minerals that function as the "active ingredient" in honing are more difficult. You have to factor in the binding material or matrix and then if the active material is say garnet the type and size of the xtls and how they are released and the type of xtl has to be considered. Garnets are rarely just spherical blobs in the matrix. The are usually dodecahedrons though there can be others and depending on what part of the xtl get the stress the hardness can vary from facet to facet and the way they breakdown will vary too. Of course as with the other types of rock the material can vary from specimen to specimen.

Remind me of the dual color to thuringian homes. It's the same stone with different properties on both sides.

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