Why don't you use ceramic stones?

[Mike Holbrook]

Several of my outdoor buddies contracted Giardia from surface water and or shallow spring water. I understand that none of them care to repeat the experience. I am also reading that Cryptosporidium (the organism most commonly isolated in HIV-positive patients presenting with diarrhea) is another Protozoa, like Giardia, with a hard protective outer layer making it resistant to many types of water treatment. Bacteria like E. coli and dysentery are larger pathogens that live in water, but like the Protozoa they are relatively easy to filter from water. Viruses, like Hepatitis A, may be less likely to occur but are not removed by common filtration systems. Be careful what you drink!

Based on the research I just did I don't think I will try filtering my water with my ceramic Spyderco stones though.

[Kees Heiden]

They're expensive there!!

Everything is expensive overhere. You should try to fill up a gastank...

[David Weaver]

Several of my outdoor buddies contracted Giardia from surface water and or shallow spring water. I understand that none of them care to repeat the experience. I am also reading that Cryptosporidium (the organism most commonly isolated in HIV-positive patients presenting with diarrhea) is another Protozoa, like Giardia, with a hard protective outer layer making it resistant to many types of water treatment. Bacteria like E. coli and dysentery are larger pathogens that live in water, but like the Protozoa they are relatively easy to filter from water. Viruses, like Hepatitis A, may be less likely to occur but are not removed by common filtration systems. Be careful what you drink!

Based on the research I just did I don't think I will try filtering my water with my ceramic Spyderco stones though.

Viruses were what was mentioned when I looked up the ceramic filters - though a lot of the little ones were combination charcoal and ceramic (speaking of the survival type or prepper type, two things I don't know anything about). They were described (ceramics) to filter bacteria but not viruses. Apparently ceramic filters encompass everything from very precise slow flow devices to things that look like flower pots.

CDC described Giardia basically as having haley's comet or shooting star diarrhea - where you might see a friend go into orbit.....

.....OK that was my summary of their description - I think they may have used the word "violent" and "persistent".

For untreated water, one of the other handbooks also suggested a higher concentration of chlorine for a longer period of time for Gardia. Sounds similar to bacterial spores, which is a bugaboo on the razor forums (except nobody knows anyone who ever got that, Giardia looks to actually be common itself). Some of the bacterial spores can survive a long duration of boiling or chlorine and were listed as being destroyed by autoclave or boiling for more than four hours. That interested factoid came up because people were arguing about how they should clean straight razors.

[Steve Friedman]

I've been away so I'm a little late to the party, but want to add that I was not willing to destroy my waterstones with carving gouges and took George's recommendation to get the Spyderco's for that purpose. Money well spent. Of course none of them were flat, but my Atoma #140 and some sweat took care of that. Would not have wanted to flatten the UF with the Atoma #400.

My one gripe about the Spyderco's is that I still don't understand how they work. If I understand correctly, the size of the abrasive particles in all three grades (M, F, and UF) is the same. One report I read was that the only difference was the binder and how quickly it breaks down. If I recall correctly, I believe the particle size was around 3 micron, which would mean that the scratches from the UF would never get any smaller than that. But I don't think that's true. Maybe it just breaks down into smaller particles. I think Spyderco represents the UF as around a 2000 grit equivalent, but that's clearly not 2000 grit in water stone parlance. Sounds like it's referring to 2000 grit in Wet/Dry SiC paper terms, which is around 1 micron.

I have also read that the difference in the stones is the surface treatment, but that bothers me. If the only difference between the F and the UF is the surface of the stone, didn't I just destroy that difference when I flattened the stones with my diamond plate?


Water stones make much more sense to me and I definitely prefer them for flat blades, but the Spyderco's are excellent for the gouges and make a great travelling sharpening kit. I do agree with David W that the Medium cuts more like a 2000 or 3000 water stone. The UF is really ultra fine.

Just want to add that for repairing edges, establishing primary bevels, and back flattening, I think PSA sandpaper (I use 3M Gold) is easier and quicker than diamond plates (or anything else) and like the fact that that abrasive breaks down. It seems to make removing the scratches much easier. I start with 80 grit until the heavy lifting is done and then spend just a few seconds on the 220 and 400 grit before moving to the stones.

That's it for now.

Steve

[ken hatch]

Thanks David,

Sounds like the brown stone, once settled in, would fit between the DMT extra fine and the extra extra fine (3mu) stones.

ken

[David Weaver]

Steve, as far as fineness, I don't know that the particles break down so much as they are dulled. There are a lot of posts online and descriptions from different sellers of stones claiming that the grit breaks down, but I think that the important step in stones cutting finer than their particle size is much more about whether or not the stone will hold on to the particle and allow it to dull. When the rubber hits the road with razors, a stone that holds its particles cuts finest when they're dulled and the stone is used then on clear water (meaning no loose particles floating around or being smashed up). It would be nice if someone would use an SEM on a stone broken in vs. one freshly lapped vs. one that has the particles "crushed" as japanese natural stones are often described as having.

In a stone like arkansas stones and the spydercos, the binder/sides of the pits probably do some of the cutting, and particles stuck together act as a group to be more like a large particle. When spyderco says (on their page) that the stones have particles from 3 to 5 microns, they probably are talking about the alumina fired into the stones, but the binder itself is a ceramic, what type we don't know, but they are generally abrasive and crystalline so if the particles stay together and have pits, they can act together whereas waterstones release the particles individually. If they made a stone that had 20 micron peaks molded into it, it would behave like a 20 micron stone until it dulled.

Like oilstones, you decide how you want to grade the stone (i.e., if you just want to clean it, or if you want to score the surface with a diamond hone and literally allow the scratches to do abrasive work), or if you don't want to grade them at all and just let them burnish.

I think they use the term 2000 grit because in terms of the grading system that oilstones used (not the JIS standard), that's probably about where 3 microns is. Natural Whetstone uses the terms 1200 and 1400 grit for their black and dark gray translucent stones, but broken in, they will bring an edge to a razor that a 8000 japanese stone will not.

In terms of ease and evenness, the waterstones have spoiled us with how consistent they are.

[Steve Friedman]

Thanks David.

Have never used oil stones (yet), but using only sandpaper, diamonds, and water stones makes it seem very weird to think that the abrasiveness of a stone can be based on something other than the size of the abrasive particles. But it does seem that the Spyderco's work more like oil stones in that regard. I can't imagine that the surface treatment alone is enough to change the abrasiveness of a stone, but the flaw is that it's based on my experience with water stones where flattening with a #140 diamond plate will make a stone more aggressive than the same stone flattened with a #400 plate. But, that effect is only temporary and quickly disappears. I guess I need to get my head around the concept that the way in which a stone works can be independent of the abrasive size. Probably the most difficult aspect for me is that Spyderco doesn't really share information well. They give out information, but it tends to be vague. I'm guessing just protecting their proprietary information.

Steve

[jean drabinowski]

Thanks David.

I guess I need to get my head around the concept that the way in which a stone works can be independent of the abrasive size.

Steve

The ceramic would be composed of polycrystalline grains. The ceramic binder is likely an aluminum oxide metalorganic precursor. Ceramic firing is normally composed of two major operations: nucleation and grain growth. The starting powder is used to nucleate the grains. The density of the grit in the binder determines the the grain packing (and spacing). The grit acts to nucleate the grain. During the sinter, the binder decomposes and to some extent becomes part of the poly grain, which typically gets bigger with longer sintering anneals. This grain size determines the grit of the stone and can be greatly influenced by the anneal conditions.

[David Barnett]

During the sinter, the binder decomposes and to some extent becomes part of the poly grain, which typically gets bigger with longer sintering anneals. This grain size determines the grit of the stone and can be greatly influenced by the anneal conditions.

When I used to make my own primitive and naive ceramic gem carving points and wheels, batches could fire hit or miss in a fairly narrow range of usefulness.

From last year's thread on ceramic flattening:
____________________________________________
As Henry Hunt says in Lapidary Carving for Creative Jewelry —

"The important thing in making ceramic grinding wheels is the temperature at which they are fired. Too high and the wheel is so hard it won't cut. Too low and the wheel wears away between eye blinks. A difference of 100° can make or break you as a wheelmaker."

And believe me, there's a lot to learn within that 100° and a lot more to it than temperature alone, which is just one reason most gem carvers have migrated to electrobond or sintered diamond points & wheels or to high-diamond-density pastes on wood.
____________________________________________

So same abrasive, same grit size, same binder, widely varying results from time and temp, cooling rates, and so on, yield different cutting characteristics even within the useful range. Makes one appreciate ready-made.

[Warren Mickley]

Here are some pictures of razor edges from Tim Zowada's site that point out the foolishness of the old 20th century grit comparison charts. Here are two pictures of razors sharpened with 12k chinese stone, one with slurry, one without. These are the same 12k stone!
zowada chi12 slurry.jpgzowada chi12.jpg

Here is Shapton 15k for comparison.
zowada Shapton15kSm.jpg

Here are Hard Arkansas and Translucent Arkansas.
zowadaHardArkansasSm.jpgZowadaTransArkSm.jpg

I have these two Arkansas stones and I think the difference is not as great as the pictures indicate. I suspect one is more broken in (worn) than the other.

[David Weaver]

I agree with your last comment, Warren. I, for giggles, took pictures of the edge of a razor after a translucent arkansas and a chinese stone and found that all of my stones imparted more scratching than the picture on the right - including a vintage japanese barber hone. I think the method tim uses has some bias toward not picking up shallow grooves.

I have or have had every stone in those pictures, and would conclude that nobody would tolerate sharpening tools to the level of the pictures on the right because they are "weight of the razor" strokes, and even laying just the weight of a plane iron on a stone would create much deeper scratches than those.

Coincidentally, one of the keenest shaves I got in the whole experiment came from a hone in a strop-top box - a brownish washita hone that, to exemplify how everything is not just put it down and drag it, created a fairly rough hone on the first shave, but after linen and strop and then several more light passes, created an edge that was about as sharp as any razor edge I've used, despite the fact that it left visible scratches.

I will post these pictures a little later.

[David Weaver]

Pictures - these are all final finish versions of each stone. I have a set of LEDs on the end of this cheap microscope right against the picture, so scratches appear more severe than they really are. Every single one of these razor bevels appears as a bright polish with the naked eye. the only thing that matters on a razor is what's going on at the edge, and how wide the edge is after it's been stropped (which you can't see with a visual microscope, it takes an SEM with some kind of measuring device to figure that out).

Ozaki mine vintage japanese barber hone:
ozaki.jpg

Novaculite 1 - bone colored semi-translucent (a fairly dense stone well into true hardness)

novac11.jpg

Novaculite 2 - a gray translucent with density 2.8 specific gravity+ (pretty close to the maximum you could get from novaculite stones):

novac1.jpg
(apologies that with a cheap microscope and cheap camera, this looks much different than the prior picture, but they're similar - for whatever reason, the angle caused the light and the software's interpretation of it to make them look a little different)

Owyhee Jasper
jasper3.jpg

Chinese agate (gave the best shave of these stones - despite the edge appearance, but totally unsuitable for woodworking - an *extremely* excruciatingly slow stone)
chinese2.jpg

The bevel that is shown here is a fraction of a millimeter. For the uninitiated, a straight razor's angle is set by it's height and spine width (it's essentially built like a large honing guide to keep the angle consistent). The scratches on the bevel don't always tell an accurate story of how the razor shaves post strop.

All of the little fuzzy bits of light that show up on here are removed by the strop.

If I use graded chromium oxide powder on a lap, I can make what looks almost like a dark (polished) bevel even at the level of this microscope, but the shave is hardly any better than it is with these stones. The reality is that the particles in these stones are much larger than 0.5 microns, but there is more to the result than the width of the grit.

These edges are all close enough together that if I use a subpar strop (like a new cowhide strop) the razor that gets a broken in horse butt strop (which has a reflective surface) will be sharper than the one that's stropped on cowhide.

[Jeff Posten]

FWIW, I lost access to a utility sink during a recent move, and now just use a 5 gallon bucket (with lid to control evaporation when not in use). A quick soak for a couple minutes and they're ready to work. And when I need to flatten, I simply rinse them off in the same bucket. I used to use separate buckets for each stone, but now just use one single bucket and haven't noticed any contamination.

Jeff

[David Weaver]

I got the 2x8 UF in the mail tonight, and it has only the tiniest lightest mill marks in it, nothing I'd be concerned about.

And it's flat enough to use out of the box. I could lap it just to be sure, but after lapping the 8x3 before, I'll wait to see if I really need to do that.

...just went down to the shop after typing the above, can't do much with a baby asleep, but I did get to work an old pexto chisel on the brown then the UF and this one is not as aggressive out of the box as the 8x3 was, it's super fine, imparts a very bright polish (used dry) and with lifting the handle of the chisel a little bit (since it's a slow cutting stone), it works a lot like an oilstone would, but even slower, and finer than any of my oilstones.

It's actually subjectively paring across the end of a board as sharp as anything I've used, and I've used a lot of things.

[Mike Holbrook]

I just got a set too George/David. The UF does seem smoother than my old fine stones. One of the things I have found concerning the old triangular stones is, no one can tell they have been sharpened. The fine, slow abrasive allows me to work the original bevel so closely there is no visible change to the bevel. If one turns the knife the right way in the light one might see how much shinier the bevel is, but the bevels on kitchen knives are so small that unless you know what you are looking for you will never know that the once dull knife is now very sharp. Unfortunately my mother & sisters have cut themselves a few times after asking me to sharpen their knives. They do not see any change and start handling the sharpened knives like they were still dull. "Never cut towards yourself, it isn't necessary with a sharp knife" but who follows that sage advise?

I like the 2x6", 400/1200 Eze-Lap too, although I have not had the chance to use it. The plastic it is mounted on does make convenient little handles for working the diamond plates over larger tools, allowing me to use the entire surface of the plates.