Revisiting the barber hone.

[stone and strop]

Grading is indeed part of why they work.
SOS does not say what the finest grit in said hone was, only that some was of a coarse nature. It had a very wide range of grit in it similar to many of todays modern hones.
Its a double edge sword though. For something to be really fast it is generally course. To be very fine - generally slow.
Some Barber hones are both. Some are not terribly fast either.
Thinking that they are all very coarse in grit and polished or buffed to the point where they behave very fine in incorrect IMO.
Lipstick on a pig is still a pig.
Polishing a very coarse hone will never make it a nice razor hone.

 

[thp001]

Grading is indeed part of why they work.
SOS does not say what the finest grit in said hone was, only that some was of a coarse nature. It had a very wide range of grit in it similar to many of todays modern hones.
Its a double edge sword though. For something to be really fast it is generally course. To be very fine - generally slow.
Some Barber hones are both. Some are not terribly fast either.
Thinking that they are all very coarse in grit and polished or buffed to the point where they behave very fine in incorrect IMO.
Lipstick on a pig is still a pig.
Polishing a very coarse hone will never make it a nice razor hone.

Yeah of course there are going to be smaller particles but what is the volume of fine to coarse? If I have 4 8K particles for every 1 4K that would still give me a 4K hone but maybe with a lot more polishing of the stria than I would otherwise get. If you look at the SEM of the surface on SOS, you can just approximate the volume of the surface inhabited by the approx - 30 micron particles, it looks substantial enough to have a significant effect on the behavior of the hone.

There's also the definition of what is fine and what is coarse. ANSI 1200 is about 5 microns which is still very fine and if conditioned in a hone could feasibly approach behavior approaching the 1 micron range, finer than 8K JIS. IMO people accepted a 'rougher' shave back in the day so a barber hone was in all likelyhood perfectly acceptable, maybe even better than acceptable.

Anyway they're just neat to have, I had an old Keen Kutter delivered yesterday that I lapped last night to add to my collection. My favorite is a small Wester Bro's dual sided hone. The ones which aren't the best for razors are great bits of Americana.