Hand Tools

Subject:
Visual difference at the back edge of..

David Weaver
..an iron or chisel.

This has come up a few times. Not talking about part of the back of a tool that's not getting abraded at all, rather when a stone seems flat (especially a waterstone with some loose grit or any stone with a slurry) and you just can't ever seem to get the edge to look like the center of the back.

I think what's happening is slurry dulling or abrading around the edge, or just in general without slurry. If you get a microscope and look at the edge and the stone is anything other than ultra fine, you'l see that the scratches at the edge are just a tiny bit deeper. If this occurs over 3 or so thousandths of an inch, it's visible to the naked eye as a slightly different finish. If the iron is sharp, don't worry about it. The only stones that seem to be immune from this are very fine stones or very fast stones where the particles are immobilized.

This was an iron sharpened with loose 1 micron diamonds. Notice in the middle of the iron, there are no discernible scratches except those left behind by prior steps. Take a look at the edge, then (this is from the planing test - the ruler trick edge is larger than the picture, so this facet is flat for the purpose of the picture).

Notice that you can make it a small area where the direction of the diamond scratches (perpendicular to the edge) become visible - but only right at the edge.
https://i.imgur.com/rmIEqnv.jpg

Messages In This Thread

Creating a mini-ura with buffing wheel?
Re: Creating a mini-ura with buffing wheel?
Re: Creating a mini-ura with buffing wheel?
finger pressure...
Side sharpening
Re: Side sharpening
Re: Side sharpening
Ruler trick
in plane iron testing, I found two options..
Re: in plane iron testing, I found two options..
testing high angles..
side comment about planing in general..
I'll demonstrate thick sometime ..
Re: I'll demonstrate thick sometime ..
Re: I'll demonstrate thick sometime ..
Patience ...
I re-read the articles on COE
High benches and low benches
Re: High benches and low benches
This isn't a snarky response, by the way
Others who do ..
Re: Others who do ..
Re: Others who do ..
Re: Others who do ..
Where I am going....
by the way...
I risk offending a lot of people...
Re: Others who do ..
on the last bit...
One other case for effort...
Something precise.
Re: Initially flat
Rotary tool?
Re: Rotary tool?
Some context
Re: Some context
Re: Some context
A failed attempt *PIC*
Re: A failed attempt
Re: A failed attempt
this is a lie nielsen iron?
Stanley iron
Re: Stanley iron
Re: Stanley iron
Re: Stanley iron
Re: Stanley iron
That pretty much covers it...
Success with applying extra pressure near the edge *PIC*
Directed pressure and progressive work
Re: Success with applying extra pressure near the
Wear bevel *PIC*
Visual difference at the back edge of..
Re: Visual difference at the back edge of..
Sorry, I should've been more precise...
Mini-ura on a new Veritas blade *PIC*
Re: Mini-ura on a new Veritas blade
Re: Mini-ura on a new Veritas blade
Re: Mini-ura on a new Veritas blade
© 1998 - 2017 by Ellis Walentine. All rights reserved.
No parts of this web site may be reproduced in any form or by
any means without the written permission of the publisher.

WOODCENTRAL, P.O. BOX 493, SPRINGTOWN, PA 18081