Obscure question of the day

[Douglas Brummett]

I have watched Garrett Hack's video over on FWW site several times. About a minute in he pulls out a beet looking medium India stone. He describes it briefly as a med stone that is glazed over and then coated with diamond paste. The effective cutting grit he feels is about 1000g.

Here is a link to the video:
http://www.taunton.com/finewoodworking/SkillsAndTechniques/SkillsAndTechniquesArticle.aspx?id=28819

He of course leaves out the important detail of what paste he used and more specifically what size grit. I imagine somewhere around 10 micron.

Has anyone here come across any more information on this sort of approach? Some reffer to this sort of thing as supercharging, but I thought that was mostly with comparable grit size to the stone. In the case of a medium India the particle size is something like 45 micron.

[george wilson]

OVERKILL!!! A diamond stone,black,and then white ceramic stone,followed by simichrome in leather strop will do anything you need to do in short order,and make a true razor edge.

[Douglas Brummett]

I agree that the process he goes through is a bit overkill. It is definitely a bit unorthodox. It is a total mut mix. First DMT stone, then the supercharged stone, an oilstone, then a waterstone, and then finishing up stropping with diamond paste.

But that isn't entirely what I found interesting. I focused in on the method of using a coarse stone as a substrate for finer honing media. I can't see anything wrong with it, in fact I think it is pretty clever. Once charged with diamonds it would last a long time. It would stay flat. The hard substrate would also keep the diamonds from embedding too deep, so it would likely work better than say a wood substrate.

George, you get a cut of the spyderco cheddar don'tcha :)
Seriously I have been reading a bunch on them since you planted the seed in one of my other threads. There are some points that I find distasteful about them, but I may pick up a pocket hone just to check out the media. Most of the folks over on the knife forums love the spyderco hones. People on the straight razor forums like them, but find them to cut too slow in comparison to a shapton. I am intrigued.

[george wilson]

What happens when the stone with the diamond does need flattening? The diamond is not going to keep the mother stone from getting worn. Actually,the diamond will cut the stone just as it cuts the steel. And,it lasts forever.You can't decontaminate the mother stone. Be careful where you imbed diamond particles.

I actually had to be talked into using the Spyderco stones.I didn't believe in them either.

When you start with a diamond stone,the ceramics only hone off the sandpapered like scratches that the diamond left. They aren't very deep. It is as quick a method as I have ever worked out.

I don't like to buff edges. It just rounds them over. If you like a rounded,but fairly sharp edge,it might be o.k..

Here's a broad hint; a certain writer of books came to a woodworking forum in Williamsburg. He made a total idiot out of himself when hanging out in the various shops afterwards.Really P.O.'ed everyone off!! he was talked about for months after.

[David Keller NC]

"It would stay flat."

Doug - No it won't. The physics of the situation prevent it. When two surfaces are abraded against each other, one will dish and the other will crown. How fast that will happen depends on the hardness and strength of the materials involved. In the case of diamonds, they are very hard (hardest natural substance), but not very strong. In any event, the substrate they're on will still wear (and eventually dish).

This, by the way, is the principle behind making glass mirrors for telescopes - one starts with a flat or slightly ground blank, then you rub it with a similar-sized flat blank on which asphaltum and abrasive are coated. After a few days of rubbing, one gets a nice parabolic shape to the mirror blank, after which it's sputter-coated with aluminum.

This, by the way, is why Rob Cosman's method for keeping his waterstones flat in his video will not work, long term (he keeps a 1000-grit waterstone as a "flattener"). Such a stone will have to be flattened against a reference surface occasionally. And that's an extra step and an extra expense, which is why a small granite surface plate and wet-dry sandpaper are recommended - one just throws away the wet-dry when it becomes too worn in the middle to get the stones being rubbed against it flat.

[Thomas Knapp]

Hi George. I have the spyderco stones also. a am fairly new to them, but I like the finish they give. I have the set of three , Medium, fine, and extra fine. What grit diamond are you using before you switch to the Ceramic stones? Do you have any other tips on them?
I also have the set of shaped stones. http://www.woodcraft.com/product.aspx?ProductID=835913&FamilyID=20254 I (http://www.woodcraft.com/product.aspx?ProductID=835913&FamilyID=20254)
I find them very useful for carving tools. I also use the triangle hone between the teeth on my veneer saw. I find it cuts better than when it is only filed between the teeth.
Thanks
Tom

[george wilson]

Thomas,I just use a 220 grit,though I have three grits,coarse (black),green,and red. Found a guy selling them cheap at a gun show.

You know how the plastic base stones with perforated diamond tops are hollow? When these stones first came out,80's?,someone donated one to Colonial Williamsburg. It is solid heavy plastic. Years ago I thought that stone was worn out,everyone abused it so,but it keeps on cutting.

I've also got one of the all metal stones. You have to be careful picking those out. They are really not machined that flat,and can be a bit hollow.



Be sure to rub down the white ceramic with the diamond if it was any fuzz on its surface. That takes the fuzz off,and makes it nice and smooth. Clean the stones with the diamond stone too. All this at the sink with some running water.

The diamond stones like Hack is using,are not very flat at all,at least not the ones I've seen. They are thin,and not very rigid.

[Douglas Brummett]

Here's a broad hint; a certain writer of books came to a woodworking forum in Williamsburg. He made a total idiot out of himself when hanging out in the various shops afterwards.Really P.O.'ed everyone off!! he was talked about for months after.

Hah, broad like the side of a barn. Small world.

[george wilson]

Whatever do you mean?