Thread: Hand American 6.0 micron compound.

Originally Posted by randydance062449

I agree with all of the above comments!

The best starting point is the micron size. After that you pay attention to the actual results on your blade.

I just acquired a 8000 Kitayama Japanese waterstone and tried it yesterday for the first time.
It was so slow!!!!!
I will try some more razors on it in the future to give it a fair test. Maybe its best use is as a touch up hone?

Randy,
This is what stemmed my question a week or so ago about using the Norton 220. At the time I was using a Japanese King 800 and it was taking forever. When my Norton 1000 arrived, it was much faster and I understood your cautions on using anything more aggresive.

I spent a goodly amount of time yesterday trying to put some reason behind various manufacturer’s differences in diamond paste grit size ratings when they have the same micron rating.

For those unfamiliar with abrasives (ie, sandpaper, stones, pastes, etc.) they’re typically spec’ed using a “grit” rating. Historically, grit size is equivalent to the “size” of the wire mesh screen used to sieve the abrasive particles, size being the number of wires in a linear inch of the screen. (E.g., 60 mesh has 60 wires each direction in a square inch and is the size commonly used in kitchen faucets, an 80 mesh has an opening which will barely pass a human hair.) All abrasives are made up of varying sized particles that fall within a size range… for example, a 100 grit stone might be made up of abrasive particles that pass through a size 100 mesh but do not pass through a 120 mesh (remember, the smaller the number the larger the hole in the mesh). For large grit sizes (e.g., for mesh numbers <240), the sieving process actually uses a wire mesh screen-like process. But for the grit sizes we’re interested in (>1000), the sieving process is much more exotic since we’re dealing with micron-sized particles.

We’ve already established that different parts of the world use different standards, but a micron is a micron, right? So why the conflict? Well, I found lots of information that pointed to nothing specific that we could hang our hat on. I found the usual references to JIS, CAMI (which is now apparently part of UAMA, so don’t be surprised if you start seeing references to that), etc.

On this document I found the statement “DIAMOND MESH EQUIVALENT - refers to micron size grading as performed by the National Institute of Standards and Technology (NIST)”, and a chart which included columns for both “mesh size” and “diamond mesh equivalent”. Here’s data for two entries in their table:

Code:

micron size      mesh      mesh equiv    micron range
    .5           25000       60000               0-1
     5            2500        3000               4-8

I spent some time on the NIST website but gave up… their site is so large that you seemingly have to what/where you want to go to be successful. So I don’t know what context to apply to the NIST statement. I do know that NIST both 1)defines measurement/testing methodologies and 2)produces measurement standards which you can use to calibrate the measuring tools/devices.

For course stones it’s economical to sieve to reasonably close tolerances… for example:

100-grit = 149 - 125 microns

As the particle size gets smaller, it’s not only increasingly expensive, but becomes technically challenging to maintain such close tolerances… for example, here’s some data I found for a US made diamond abrasive:

Code:

  mesh         micron range       average(*)
    8000           4 – 2               2
   15000           2 – 0               1
   60000           1 - .25             .625
(*)calculated by me

Now, my hypothesis as to why manufacturers grit specs differ for the same micron-size…

According to here US manufacturers (including Norton, although they are now owned by a European company) spec according to the larger of the size-range of particles. Hence, using the table above as the example data, a 2 micron rated abrasive using the US method (micron range of 2 - 0) would equate to something around 15000-grit. The European convention is to spec to the average particle size… thus a 2 micron rated product (4 – 2 micron range) would equate to approximately 8000-grit. So, the bottom line is that the micron rating from some companies is the largest particle size in the abrasive and for others it's the average particle size.

Now, before we get too cocky about all this, most manufacturing processes create a non-linear distribution of particle sizes within the range… e.g., there might be more larger particles than smaller, so the average is not necessarily the midpoint of the range that I’ve used as examples above. Hence, it’s very difficult to compare product from different vendors even when you know the particle size range.

My standard stone that I use following the 8000 Norton is the 12000 Chinese natural waterstone. I generally use 50-100 laps on that stone.
I did not try that many laps on the Kitayama but will try it with high reps next time as a substitute for the Norton 8000 and also as a substitute for the 12000 Chinese hone. It does feel very fine, similar to the Chinese 12000

Thanks for the input

Originally Posted by Korndog

This stone is sometimes marketed as a 12k Randy. I have been told that the effective grit is somewhere in the 12-15k range once a slurry is raised. Could that be why it seems slow to you? Of course nothing that I have tried cuts faster than Shapton pro stones..

Hey Azjoe! Good post!

Originally Posted by randydance062449

My standard stone that I use following the 8000 Norton is the 12000 Chinese natural waterstone. I generally use 50-100 laps on that stone.
I did not try that many laps on the Kitayama but will try it with high reps next time as a substitute for the Norton 8000 and also as a substitute for the 12000 Chinese hone. It does feel very fine, similar to the Chinese 12000

Thanks for the input

Why do you need so many laps after coming off a stone that so close in grit? Is the Chinese stone that slow?

Awesome post Joe. Can you put the charts in the files section? Thanks alot. Lynn

Originally Posted by adjustme69

Can you put the charts in the files section?

Done! I revised the document slightly and added the charts inline instead of referencing their URLs. It's in "Help Files/Permanent Archive/Honing & Stropping Information/why diamond pastes have conflicting grit sizes"
...joe

Originally Posted by randydance062449

My standard stone that I use following the 8000 Norton is the 12000 Chinese natural waterstone. I generally use 50-100 laps on that stone.
I did not try that many laps on the Kitayama but will try it with high reps next time as a substitute for the Norton 8000 and also as a substitute for the 12000 Chinese hone. It does feel very fine, similar to the Chinese 12000

Thanks for the input

I have a Shampton 15K. I am working on a razor that is almost there. It does not pull too much when I use it, but neither does it take off much. Would you suggest using 50 to 100 reps to get it closer to super sharp? Then what, go to the .5K leather strop or to the plain strop before shaving?

jmsbcknr

Originally Posted by jmsbcknr

I have a Shampton 15K. I am working on a razor that is almost there. It does not pull too much when I use it, but neither does it take off much. Would you suggest using 50 to 100 reps to get it closer to super sharp? Then what, go to the .5K leather strop or to the plain strop before shaving?

jmsbcknr

From microscope photos, I can see that leather stropping makes a big difference after the 12K stone. The fin looks taller, which suggests that some kind of fin alignment is taking place. Maybe a stone causes the individual microserrations to spread out and the strop makes them stand up again.

In any case, I think a pasted strop should have that same effect. So, the benefit of using leather must be that it polishes down the scratch lines. You can see that. Those scratch lines contact the skin when you shave, so it seems that smoothing them would improve the smoothness of the shave. Of course, there has to be a point where it doesn't make a difference. A .25 strop is like a 100K abrasive, so it might already be at that point.

Being able to tell whether leather stropping makes a difference after a .25 strop will require some experimentation. I just do it out of habit.

Chaaaz was the first person to experiment with that many laps on the 12000 stone and had success. So, I tried it and also had a noticeale improvement in the blade edge. From that I guess you can conclude that the Chinese 12000 stone is very slow cutting.

Originally Posted by Joe Lerch

Why do you need so many laps after coming off a stone that so close in grit? Is the Chinese stone that slow?