Thread: Question for JimR: "False Edge" definition...

First of all, good on 'ya for translating "Honing Razors & Nihonkamisori"! Amazing to read that document! Big thanks are in order!

I'm curious about a phrase Iwasaki says a lot: the "false edge". He clearly differentiates it from a standard wire edge, so it seems like it would be something else. It sounds almost like super-fine microchipping or some kind of micro-burr, but I have no idea, really. Am I warm or miles off?

Is not micro burr a wire edge?
He is talking about the fine serrations left by the finishing stone, those define the "false" edge.
He then talks about using CrO to remove the serrations and create smooth (as in no serrations) even edge.

Thanks very much for the kind words.

I think what Stefan says is mostly the truth, but I still am not sure. To be honest, I still have yet to find any serrations left by a natural Japanese hone. I wonder if the False edge refers to a phenomenon caused by the enormous amounts of pressure he uses when honing Kamisori.

I've read the document (which is just amazing !! Thank you so much JimR !!)

From what I understand, he talks about removing the false edge for Komisoris as well as razors.
Since he uses mettalurgy microscopes to look at his edges, he must have seen things that we are probably unaware of.

Whatever he saw was removed after the CrOx & the 1mm back & forth movement on his last finishing stone, so I'm tempted to try that to see if it does anything for me. But instead of doing it free-hand, I'll put a few layers of tape. I wonder if it'll work for me.

I'm still wondering why it would take do much time to do that last finish step...

Originally Posted by JimR

Thanks very much for the kind words.

I think what Stefan says is mostly the truth, but I still am not sure. To be honest, I still have yet to find any serrations left by a natural Japanese hone. I wonder if the False edge refers to a phenomenon caused by the enormous amounts of pressure he uses when honing Kamisori.

JIm,
I am in agreement here, for me from my finest stones the edge is ready to shave no stropping recuired right off the stone.
May be what Iwasaki is talking about is Kamisori, because they are made from harder steel and that might have an effect, that is the only thing I can think off.

i didnt understand this edge finishing. how should i place the edge on the stone and move 1mm? could someone make a picture?

Sicknote, I translated what was there. There are no details--it's something you have to investigate.

Originally Posted by sicknote

i didnt understand this edge finishing. how should i place the edge on the stone and move 1mm? could someone make a picture?

I think he talks about making a microbevel.

Originally Posted by JimR

Thanks very much for the kind words.

I think what Stefan says is mostly the truth, but I still am not sure. To be honest, I still have yet to find any serrations left by a natural Japanese hone. I wonder if the False edge refers to a phenomenon caused by the enormous amounts of pressure he uses when honing Kamisori.

Wow, Jim, I just read this (downloaded from a blog). I missed the annoucment on SRP if there was one, but I'm glad PA23 asked the question and made me curious.

Originally Posted by PA23-250

First of all, good on 'ya for translating "Honing Razors & Nihonkamisori"! Amazing to read that document! Big thanks are in order!

I'm curious about a phrase Iwasaki says a lot: the "false edge". He clearly differentiates it from a standard wire edge, so it seems like it would be something else. It sounds almost like super-fine microchipping or some kind of micro-burr, but I have no idea, really. Am I warm or miles off?

You are right ... this section seems odd to us with modern hones.

He is working with old school Japanese steel and natural hones (Jnats) and
this seems to define what he is doing.

Old school steel, if I can coin a phrase, can be very hard. Woodworker
tools from Japan and razors might be R62 or perhaps harder. Without the backing
of soft mild steel/iron they would be too fragile/brittle to use. Most razors
are not this hard.

Natural hones have minerals softer than modern man made hones.
While the grit starts out less uniform it breaks down into a fine abrasive.

Now some serious guessing.
Limiting the final honing to a couple of millimeters would build, concentrate
and localize a micro fine slurry and even cause a mini dip in the hone
that would result in a micro fine micro bevel as the edge climbs
out of it.

How one might obtain that same fine edge with modern tools
might take a microscope and some experimenting. And in
the end a shave test.

Do a web search for "Popular Science Oct 1931" razors.
this was the golden age of optical microscopes and razors
of all types...... There are some classic microscope images
that tell a lot.

The 2 mm strokes reminded me that there is
another place to look. Look for older "American Optical" literature on
honing microtome blades/knives. The final honing was done with
chalk on glass by vibrating the glass under the razor/microtome
blade. FWIW there was a comment elsewhere that this edge
was not fun to shave with, it would slice anything put in
front of it -- i.e. my definition of a harsh edge.