Sharpening Stone Identification Request

[Jonathan McCullough]

I currently use mostly DMT sharpening stones and a strop, but have been looking for an intermediary stone of some sort to bridge between the DMT's highest 1200 grit Duo Sharp and the strop, so I've been buying oddball passed-up sharpening stones when I see them. Despite the fact that great debates rage here about how best to sharpen things, and what to use, I think the average person could not sharpen their way out of a wet paper sack, so these stones show up from time to time for a buck apiece at yard sales and what not.

They are unfailingly filthy, clogged up, and abused, so I kept a growing pile until I could boil up a batch of stones with some TSP, as advised on the Norse Woodsmith blog. I scrubbed these and boiled them a second time.

http://i575.photobucket.com/albums/ss199/Jonathryn/haul%20of%20the%20day/Stones.jpg

Some people can identify stones by sight, alas I can't, so I'm throwing myself on the tender mercies of the SMC to let me know what these may be, if anything. Could you help me identify them?

The first (from left to right) did not bead up water and seemed relatively clean, so I didn't boil it with the oil stones, as it seemed to be a water stone. It looks like a very stable, fine, and uniform limestone.

The second one is an oilstone, and although it seems variegated it's actually very smooth to the touch. It, along with the fourth one, was in a machinists' box.

The third one is a combo stone, I'm going to guess it's got Crystalon on one side and a very smooth, glazed, fine, almost glassy surface. Possibly a white translucent Arkansas?

The fourth one is relatively coarse compared to the others. I'm going to guess it's a white Washita?

[James Taglienti]

I'd say the middle two are some sort of carborundum. I havent heard of them bonding carborundum with natural stones but they might have done it. The left stone looks like a hard white arkansas and the far right like soft or washita.
that's just at a glance.

had good luck cutting natural stones with a regular hacksaw, and they also belt sand fairly easily, if you're looking to remove the glazing.

i usually toss old carborundum stones or use them to dress my frangible grinding wheels. you can also use them to "dress" a worn wire wheel while it's running. i havent found a decent way to remove dishing from them, theyre so dang hard.

[john brenton]

The third from the bottom looks like what is commonly known as an India stone.

Why not just spring for the 4000/8000 Norton? I know its a little pricey and I really did wait to buy it, but I'm definitely 100/ satisfied. The DMTs in the coarser grits and the Norton stones in the high is the way to go...IMHO that is!

[Jonathan McCullough]

That's good information gents. I used the limestone-y one on the left to sharpen some kitchen knives--it made a slurry, sharpened the knives up well, and gave up a very odd smell: stale cigarette smoke and the catacombs of Paris.

I'm looking forward to conditioning and using the others. The suggestion of the Norton combo water stone is a very good one, but my shop is unheated and a stone pond in January would probably be more suited to skating than sharpening. Picking up a gem at a yard sale also appeals to my sense of, ahem, frugality . . .

[john brenton]

I'm stupidly frugal. I'm the buy crap ten times instead of buying good once guy. But, the Nortons high grit only need a spritz, no saoking necessary.

I'm not saying its gospel, but I had read an article about rouge stropping where a guy was badmouthing it, and although his delivery was harsh and a little insulting, I have found his criticism to be somewhat accurate. Before getting the Nortons I honed on a flea market black arkansas and stropped to get the mirror shine. Although I was easily achieveing razor edges and producing ulta fine shavings, glossy surfaces etc. after reading the article I noticed that its deceptive. You can put a mirror shine on anything with a rouged strop. Getting the mirror shine with no visible edge on the stones, and using the rouged strop only for a little perfecting and whetting and straighting the microscopic teeth makes a big difference IMHO.
That's good information gents. I used the limestone-y one on the left to sharpen some kitchen knives--it made a slurry, sharpened the knives up well, and gave up a very odd smell: stale cigarette smoke and the catacombs of Paris.

I'm looking forward to conditioning and using the others. The suggestion of the Norton combo water stone is a very good one, but my shop is unheated and a stone pond in January would probably be more suited to skating than sharpening. Picking up a gem at a yard sale also appeals to my sense of, ahem, frugality . . .

[Jonathan McCullough]

If I'm reading you right, what you're saying is that you can rouge-strop a mirror finish onto a chisel that's dull as a spoon, because a shiny bevel tells you nothing about the edge? One of the things I've noticed is that sometimes, some of my "mirror finishes" can have abrasive streaks left by previous, coarser stones. Sometimes the edge is sharp as I'd like it, sometimes not. That's why something in the 2,000 - 8,000 grit range would be useful. Plus, the oilstones would be good for gouges; the DMTs are made with perforated metal, which doesn't really work all that well for gouges.

[george wilson]

The first stone COULD be a Belgian natural honing stone. A bit hard to tell just from the photo. It could also be a Japanese water stone,which I do not use,so am not familiar with the types. The 2 layer one is,as said,a combination India stone. It is a decent general purpose stone. The orange side is all I ever used. I never use mine any more since I went to diamond as a primary stone for quick metal removal. Not sure about the other 2 from the picture.

[Jonathan McCullough]

By George, I think you're right. It seems to be a "Belgian Yellow" that's glued to some slate. Are they uncommon? That one cost 25 cents. Worked pretty well--as it should. I polished the orange side of the combination stone today with a diamond stone. It's very hard, smooth, and now flat. I think the coarse white one is a Washita but the other, brown one is rather smooth.

[David Weaver]

By George, I think you're right. It seems to be a "Belgian Yellow" that's glued to some slate. Are they uncommon? That one cost 25 cents. Worked pretty well--as it should. I polished the orange side of the combination stone today with a diamond stone. It's very hard, smooth, and now flat. I think the coarse white one is a Washita but the other, brown one is rather smooth.

I don't know if they're too uncommon, but they're not cheap and plentiful like old carborundum stones. They sell pretty well if you can verify what they are, especially if they're larger. In the days of arkansas stones or other natural stones, the yellows are finer stones and they have garnet in them and cut more steels well.

They're popular with the razor guys, but I don't know enough about razor sharpening stones to know what proportion of folks will pay $250 for a big yellow and what's popular with them. When I was learning to sharpen a razor, a lot of the same discussion goes on in the razor forums - trying different stones, etc, except some seem to like a stone that doesn't cut deep grooves like a shapton does, though there were plenty of people using those, too.

http://www.theperfectedge.com/belgian.shtml (http://www.theperfectedge.com/belgian.shtml)

I've never tried one of the yellows because the big ones cost almost as much as a good japanese natural waterstone :( Really cool if it's really a belgian yellow and you got one for 25 cents.

[john brenton]

That is precisely what I'm saying....but I really don't know exactly how critical it is. I just see it as good practice to eliminate any belly on the bevel and get a true attack angle and more integrity in the edge instead of a kind of very minute convex shape to the bevel that the rouge stropping hides so well.

My test for sharpness is flashing the bevel against the light. If I can see that thin line of light on the very edge of the cutter then I work to take that off.




If I'm reading you right, what you're saying is that you can rouge-strop a mirror finish onto a chisel that's dull as a spoon, because a shiny bevel tells you nothing about the edge? One of the things I've noticed is that sometimes, some of my "mirror finishes" can have abrasive streaks left by previous, coarser stones. Sometimes the edge is sharp as I'd like it, sometimes not. That's why something in the 2,000 - 8,000 grit range would be useful. Plus, the oilstones would be good for gouges; the DMTs are made with perforated metal, which doesn't really work all that well for gouges.

[george wilson]

The Belgian stones I have seen were NOT HARD. Woodcraft,years ago,sold odd shaped Belgian stones ground flat. I have a razor stone with cream on 1 side,and the natural purple harder layer on the other side. They are not glued together,just 2 layers of sedimentary stone. It still had the decal on the purple side identifying it. The old cabinet maker in Williamsburg when I first got there used one of the odd shaped Woodcraft stones. He'd SPIT on it and hone his Swedish chisel!!

These are not hard stones,though,more like very fine limestone.

[Jonathan McCullough]

Yeah, that makes a lot of sense that someone would/could just spit on it. Wonder if that's where we get the expression, "I just gave that one a spit and a promise"? It lathers right up with slurry. I flattened all of them today with a 325-grit DMT stone and some soapy water, using a pencil to mark my progress, which took a lot less time than I thought it would. They're all flat and "smooth" now, with that sort of tactile sense that it sort of "grabs" the skin on your fingertips so subtly that you can *just barely* sense that they're abrasive.

Unlike the analytically quantifiable DMT DuoSharp stones ("220 grit" "325 grit" "600 grit" "1200 grit") I'll probably never know what specific degree of abrasiveness any of these really are, and will have to just try them out and go by feel. Regardless, I have the feeling these will do a really fine job and were well worth the $7.25 investment. Maybe the next thing should be to make a little sharpening fetishist's box for them . . .

[David Weaver]

Generally want to keep anything that's not plain water away from natural stones that are friable. I don't know if the coticules are really a lot like natural japanese stones, but with a natural stone that's not an oilstone, you never know what will break down the natural binder/matrix.