whats the difference between the blue/green (gray!) escher and a yellow/green escher?
Fred
Printable View
whats the difference between the blue/green (gray!) escher and a yellow/green escher?
Fred
y/g is softer? is that right?
I know what you mean about liking natural products better. I also know what you mean about the never ending quest for The Perfect Edge. I have a collection of over 400 stones from around the world and have honed on most of them. I have eschers in blue/green and yellow green, japanese stones, Tam O'Shanters, Water of Ayr stones, Eidsborg, Thuringien, and of course a healthy collection of belgians in blue, yellow, and some shades in between.
The garnets in the belgians have a unique property which makes garnet a great abrasive both in sandpaper as well as in stones. It cleaves. It's not that the whole rhombic dodecahedron comes out of the surface but as the steel passes over the crystal, the crystal fractures and produces tiny particles of abrasive in the slurry. The belgian phyllite (colloquially known as "mudstone") is softer than the Escher, Thuringian, or Japanese substrates. That helps to bring fresh, sharp garnet edges to the surface to be cleaved by the steel. The slurry is an abrasive slurry and is akin to the lapping used to fit valve heads to the head in an automobile engine.
Your statement about the relative garnet contents is an interesting one. I haven't seen any studies on it. Was that an opinion or did you actually get some data on that?
Fred I have the same interests in stones. I have just purchased my first coticule and debated a "esher" as well. I am under the impression that the polishing and etching action on the bevel of the coticule is superior to the esher as shown on zowda's site, while the edge remains debatable.
http://www.tzknives.com/razorbevels.html
I am wondering, if a esher is used after the coticule will it wear away the desired etchings on the bevel?
:roflmao:roflmao:roflmaoWelcome to the deep dark world of HAD. You've been bitten by the HADdus Flyingensius bug. There is no cure.
Natural stones are great and fun to experiment with no doubt.
If the garnets are the same size in the blue and yellow coticule, why does my blue leave a coarser scratch pattern on the bevels?
Chris L
One could argue that if the size of the garnet is the same, and the garnet distribution is less dense, then the force exerted from the weight of the blade would be over fewer points, thus gouging out more steel because of the increased pressure at those points (the same weight would be supported by fewer peaks, creating more pressure at each individual peak).
Additionally, I think this argument stands no matter what the size of the garnet is because the crystal will only penetrate the surface so far, and that is not even the depth of the "finer" specimens in the Coticule. So you might be able to say that the difference in garnet size will not make as much of a difference as the concentration in the stone.
And to throw another wrench in the gears, how do the vintage Coticules factor in against the newer ones? I have always understood the vintage ones as being finer and having more garnet, but if someone knows differently I'd appreciate being corrected.