Ceramic benchstones compared to DMT extra-fine?

[carpdiem]

I've got a full set of DMT benchstones (from x-coarse to x-fine), and I'm thinking of picking up some of the spyderco ceramic benchstones. I'd be interested in hearing some user opinions about them, though. How do they compare in roughness to the DMTs? I presume the x-fine spyderco is much smoother than even the x-fine DMT, though I'm not sure how much of a difference it'll make to a finished edge. Anyone have these and care to coment?

[Native Justice]

They are very nice! I have the UF and use it prior to progressing to my 8000 grit waterstone for the final mirror finish.

FYI ...

Spyderco benchstone grits

Med 12-14 u 800-900 grit

Fine 7-9 u 2000-3000 grit

UF 3-4 u 4000-6000 grit


DMT Benchstone Grits


XXC 120 u 120 grit

XC 60 u 220 grit

C 45 u 325 grit

F 25 u 600 grit

XF 9 u 1200 grit

Ceramic 7 u 2200 grit

XXF 3 u 8000 grit


Good Luck!

NJ

[carpdiem]

Native Justice,

Thanks for the info! One more question, though. I understand the last numbers you give in the grit rating for the benchstones above, but what does the first part "ex: 12-14 u" mean?

[Native Justice]

Those are the relative micron sizes for the respective grits. Most of the japanese stones are measured in microns as well as many manufacturers (Nortons website does the same thing) which give you additional comparison information product to product, manufacturer to manufacturer. Sorry if I confused you. Sometimes too much info is just too much, lol. :o

NJ

[carpdiem]

Ohh... thanks Native Justice! That's actually a really cool way of describing the surface roughness. I'm a physicist, so don't worry about too much information, it's just that I'd never seen roughness presented that way before.

[sal]

Hi Native Justice,

I would be curious as to where you got your numbers for the ceramic stones. All of the ceramics use the same micron size (15-25). the different grits are created by different carriers, different firing techniques and diamond surface grinding.

sal

[JD Spydo]

Now all you guys have me confused :confused: But I had heard Sal say in the past something about the fine & Ultra-fine Spyderco stones having virtually the same molecular make up but the 2 of them had different finishes put on them.

I have seen a chart similar to the one Native Justice put up on one of the main manufacturer's websites but I'm not sure whether it was Norton or 3M.

I'll say one thing for sure; I've had at least 4 different brands/makes of ceramic sharpening stones and none of them compare to the Spyderco Stones. I also got to talk to a guy from Arkansas this last fall and he used to work for one of the companies that mined the novaculite ( Arkansas Stones) and he told me that nothing he ever worked with compared to the endurance of the Spyderco stones.

Also I would like to know how the Spyderco ceramic stones stack up against the Shapton Stones that have had rave reviews here in the last year.

[Cliff Stamp]

All of the ceramics use the same micron size (15-25).

Sal, a few years ago I compared a new DMT fine stone to the medium and fine ceramics from a Sharpmaker using both the resulting sharpness and scratch pattern to estimate the relative "grits". Knowing the DMT was 25 micron the ceramics were set to be 11.5-13.5 and 5.5-7.5 respectively. Since I posted this up I have seen similar numbers used, and of course as is common with internet information, sources are rarely cited.

-Cliff

[Native Justice]

Sal, a few years ago I compared a new DMT fine stone to the medium and fine ceramics from a Sharpmaker using both the resulting sharpness and scratch pattern to estimate the relative "grits". Knowing the DMT was 25 micron the ceramics were set to be 11.5-13.5 and 5.5-7.5 respectively. Since I posted this up I have seen similar numbers used, and of course as is common with internet information, sources are rarely cited.

-Cliff

Sal & Cliff,

That's exactly how it was done, based on comparative scratch patterns with known grits.

NJ

[sal]

We've spent a great deal of time trying to determine grits for our stones. The manufacturer has also worked with us, to no avail. A guess seems to be best.

Most abrasives are measured by the grit size used in the matrix. Our ceramic doesn 't work that way. Grit size is constant.

We've tried to compare scratch patterns as Cliff mentioned and this is probably the closest, but nothing that we can say "This is blah blah". Then the Japanese water stones jump into the equation and suddenly there is whole new set of numbers.

So where we end up is:

Our diamonds are a 400 mesh (measureable). (600 on the Duckfoot)

Our gray stone is "medium". (Same material as fine but different carriers and heat treat).

Our fine stone is fine.

Our extra fine is a surface ground fine.

:o

sal

[Native Justice]

Sal,

I'd hoped to offer comparitive info for Carpes use. Most of the sharpening public doesn't care about much more than than whether or not the stone is Fine, Medium, etc. but there are others of us that have taken it a tad further and have desired more info. That's where the grid info came from.

NJ

[rescueseven]

Sal,
I understand that you are not willing to say that the ceramics are the same as 1200 grit, or the same as 2500 water stone or the same as a 3µ particle. Because saying any of those things would just not be accurate, and would be the same as using a unit of weight to describe distance. “I live 12 pounds 7 ounces from Spyderco”. And describing these things as something they’re not would be deceiving, and I think we all know that being deceiving is something you are not capable of.

But the problem still remains as to how to describe the ceramics, and where do they fit in the big picture. The store that I work at (nationwide woodworking supply store) we carry something in the neighborhood of 40 different bench stones; ceramics, water, Arkansas, diamond, and others. I noticed the other day that the shelf labels for the Spyderco ceramics have a grit listed with them, and these same numbers are used in the web page descriptions also. From the web page- Spyderco Bench Stone Ultra Fine/2000 Grit 2" x 8", there we go again, apples and oranges.

In my travels on the ‘net I found this table that kind of puts things into perspective as to where all these stones fall, whether or not it’s accurate is another question. But I think this is the kind of answer the original poster, and some of my customers, are looking for, and is the comparative info that NJ was trying to convey.

It is important to me to know that the difference between a Spyderco fine and ultra-fine stone is the surface preparation of the stone, much like the difference between a 2nd cut file and a bastard file is the surface preparation of the steel. But I would also like to know that Soft Arkansas, Lansky Fine Hone, Ultra Fine Scotch-Brite Pad, and Spyderco Medium Ceramics are all going to do similar things to an edge on steel. My problem is I’m not in a position validate these statements. Do you think your products are accurately placed on this table? If they’re even close I’m going to print this list and drop it in my apron at work.

Thanks for your time,

Ian

[redback]

It's a pity we cannot know the grits for the ceramic stones. I'm looking for a 4000-8000 grit stone to use on my new straight razors, and without a grit guide I'll have to buy another product, like a Norton 4000/8000 combination hone.



There is a table here that may help:
http://carverscompanion.com/Ezine/Vol1I ... ngham.html

[sal]

I used the UF on my straight razors when I was shaving with a straight razor. It worked well. The real performance comes from the strop.

sal

[FLYcrash]

Cool thread! Good to see you around, Mike, and thanks to everyone for such nice delineation of some confusing stuff.

My experience is that the DMT Extra Fine product gives a bit coarser edge than Spyderco's white ceramic. On my plain edge knives, I sometimes sharpen with DMT the whole way from X-coarse to X-fine and then finish on Spydie whites.

The Norton 4000/8000 is an excellent stone to use for honing straight razors and also touching up plain edge Spydies. I'm sure that the Spyderco UF stone is also awesome, especially now that it comes as a benchstone, but I don't have one so I can't compare. Thanks, Sal, for your input on this application!

[Cliff Stamp]

It's a pity we cannot know the grits for the ceramic stones. I'm looking for a 4000-8000 grit stone to use on my new straight razors, and without a grit guide I'll have to buy another product, like a Norton 4000/8000 combination hone.

I am sure Sal could give you a set of meaningless numbers if you really wanted. Grits are not actual quantified numbers, they are just thrown out by manufacturers. They are no different than ranking stones by coarse/fine/x-fine. There is nothin saying for example that what Norton means by grit has to have anything to do with what Spyderco could use for the same term. The actual scratch pattern results are given in the above if you want to know the finish they produce.

-Cliff

[Native Justice]

It's a pity we cannot know the grits for the ceramic stones. I'm looking for a 4000-8000 grit stone to use on my new straight razors, and without a grit guide I'll have to buy another product, like a Norton 4000/8000 combination hone.



There is a table here that may help:
http://carverscompanion.com/Ezine/Vol1I ... ngham.html

Red,

Refer to the grit data chart I posted earlier for useful detail. Let me know if you need more info.

NJ

[redback]

Ok. But I buy everything off eBay and there are no Spyderco Ultrafine Ceramic whetstones for sale there (w/ "Buy It Now" & PayPal)... wonder why not?

[redback]

Now I'm reading good comments on other forums about the Spyderco UF stones, so I'm going to get one, come **** or high water! What I like about the ceramic over the water stones is that the ceramic will last a loooong time, whereas the Norton is a soft stone that wears away before too long.

[sal]

Our Ultra fine stone took many years to develop and few know about them. I was convinced enough with the stone's potential that we finally were able to make a 3" X 8" version that is not much more than a quarter inch thck. Two sides, flat and fine.

It took five years for our R&D teram to finally produce this stone. The challenges kept cropping up and needed to be overcome. Technology in the area of ceramic stones has improved and we can now make stone shapes before not possile.

We have the new UF 3X8, a 2" X 4" fine slipstone with 1/2" down to 1/8". And we also have a ceramic version of the byrd duckfoot, fine grit. A true "Golden stone". The downside is the high cost.

50,000 years from now when the Pyramids have crumbled and humans are but a memory, Spyderco ceramic stones will be seen sticking out of the earth, ready to work.

sal