Thread: Wondering about grits!

Good Day Folks!

I was looking at the Shapton stones and noticed that they list the grit and also the particle size.

The 16000 grit stone is listed at .92 Microns, so if I paid any attention in grade school, I'm guessing my 8000 grit stone would be somewhere around 1.8 Microns. Now if I paid attention at middle school, I'd guess my 12000 to be near 1.4 Microns.

If my math is right, than I think what I've realized is that red paste (2-4 Microns) isn't helping me out very much. I had observed this while using it, but I couldn't figure out the reason why!

I think I know where I need to look in search of that final polish now, but I just wanted to see what you folks think about the grit and particle size assessment

Thanks!!

I like Grits too personally, I prefer them with a lot of butter and some salt and pepper


Yer math is almost dead on IIRC the 8000 Shapton is marked at 1.92...
The one thing yer not taking into account when it comes to pastes though, is that they don't work the same as stones do....
The Dovo Red paste is rated somewhere deep in the forum as 2-5 microns
The Dovo Black paste is rated at 1-3
But neither cuts all that harsh in real life.... they are both rather mild polishing abrasives

Sigh..... if only life were so simple. I'm afraid I'll have to muddy the waters a bit on this issue. The unfortunate truth is that grit ratings and actual particle size is only a small part of the wonderful world of abrasives. Take a simple piece of 100 grit paper, 100 grit as in an average count of 100 abrasive particles per square inch of paper... BUT, is this normal paper or open coat?!?! (open coat means there is more room between each particle so the paper does not clog as easy and thus particles must be smaller in order to have the same count but more space between them).

Now consider what material is the grit made from... is it manufactured to close tolerances or is it one of the natural mined grits, crushed and screened... was it screened to remove smaller particles or is it a mix? What are the properties of the grit, some are rather roundish like the garnets found in Coticule hones... they have facets on the surface, giving a much finer cutting action than their size would dictate... then again, put them in a loose slurry on top of the stone and they cut very differently. Some types of abrasives are very sharp but dull quickly, others fracture and generate new cutting surfaces as soon as they begin to dull. Man made ceramic grits are very sharp, like glass shards and are very wear resistant. Man made diamond dust is different from natural diamond dust, there are mono crystaline diamonds and poly crystaline diamonds with the latter tending to fracture when they dull as mentioned above but become finer when they do and thus cut as a finer grit than what they started out as. I could go on and on (yes, I know... I have already) but what I wanted to say was that the grit *size* cannot by itself dictate what the cutting action will be like unless you are comparing two grits sizes of the exact same marterial. Just because the grit may be 2 micron in size does not mean it cannot improve on a surface created by a 0.5 micron grit particle of a different material. Just look at metal polishing compounds, one type made to put a mirror finish on carbon steel could be useless for polishing copper, hardened steel is very different from soft stainless and each polishing compound is made with one or more types of abrasive and often with a mix of particle sizes that they have found through trial and error to work best.

So, the bottom line is that if you have something, try it... if it doesn't work, try something else but keep the first product handy for a while... you never know, it might just work really well on the next new razor or perhaps at a different point in the process. I've just gone through the Shapton upgrade... nice hones and really fast cutters, but I'm discovering that my Coticule really does a fine job on polishing those ubersharp edges that I can generate with the Shaptons... I go to 16K on the Shapton but the 8-10k garnets in the Coticule still *improve* the edge afterwards for me. I get far better edges from my Coticule now than I used to before I got the Shaptons.

Regards

Christian

I agree with the above. Personally, I quite like the Dovo red paste on my hanging strop - it gives me edges that seem to be better than the 8K, despite the micron rating.

James.

Kaptain Zero,

Thank You for all of the information!

I hadn't even considered the effect of different mediums, until gssixgun had posted.

I've only been shaving and honing for about 1 year now, and boy I've got a lot to learn! Luckily I'm dedicated and I also have such a wonderful reference thanks to all of the reply posts I get to my silly questions!

I appreciate the time and consideration all of you have provided me.

Well, when you figure it all out.... please give me a call! I've been at this for some time now and the more I learn the more lost I get.

I think the things I've learned the most from is when someone who has way more experience than me reports that they get better results than I do with a given piece of gear. After lots of head scratching and trying this and that, I usually find I'm able to duplicate the results even though the first attempts indicated that said experienced gent must have been "out to lunch". Case in point, I owe a tip of the hat to Howard of theperfectedge.com who's repeated statements about the coticules and how they've been all that was needed for centuries when it comes to maintaining straight razors made me re-visit my coticule again and again until it finally clicked and I began to get the results he's always described. No, it's not a miracle hone, but dang... it's pretty darn good at what it does.

Regards

Kaptain "Some people think I have an abrasive nature and I have no idea why?!?!" Zero

Originally Posted by kaptain_zero

I think the things I've learned the most from is when someone who has way more experience than me reports that they get better results than I do with a given piece of gear. After lots of head scratching and trying this and that, I usually find I'm able to duplicate the results even though the first attempts indicated that said experienced gent must have been "out to lunch".

OMG so +1 here
I also read very carefully the posts of the new guys, because their perspective has not been jaded with the "knowledge" of the ages, and I do find some value in re-looking at things from a different view..... "Many have much to teach, everyone, has something to learn".....

Is it really nescesary to use paste? I have a rough canvas on my strop, inst that good enough?

Originally Posted by The_Pastor

Is it really nescesary to use paste? I have a rough canvas on my strop, inst that good enough?

In my limited experience I would say it is not necessary but it will improve and edge if you do use it. After honing a razor I strop and shave. If after the first pass I conclude that it needs a bit extra I hit it 5 round trips on a felt pad with Chromium Oxide and it improves the shave every time. I don't paste my linen strop as I want to keep it as is. Once you put it on it is hard to take off. Many forum members use balsa wood or some other surface including newspaper. A lot of people report great results with pasted hanging strops. If I ever go that route it will be in addition to my regular non pasted strop.

The grit size tells you about the size of the abrasive particles. Some particles are roundied some have more spikey points. Apart from that the abrasive particles are embedded in a matrix or leather or balsa in the case of pastes. Or they are fully exposed in the case of a slurry. The matrix itself may have more or less pronounced additional polishing properties as well. Last but not least: different abrasive particles have a different hardness.