Thread: That shaped hone...

Yes the convex hone. Not really about the hone itself but I know that some are skeptical of the historicity of the claim. I was pointed to a text which would seem to verify that the idea was around and in use in Germany at least around the 1850's. This says nothing of it's use before or since.

In addition to this there are some more paragraphs in other publications I am working on translating out but it will take a little time.

The book is called Polytechnische Mittheilungen published in 1846, Volume 3. It is available to view on Google Books and anyone can verify my translation for themselves.

https://www.google.com/books/edition...C?hl=en&gbpv=1

The important text is on page 29.

The practical effects of the hone are not important for this thread, I don't want it to degenerate like the last one, I just wanted to share that there is at least some kind of evidence of it being 'a thing', enough of a thing that a German journal for technical colleges would document it.

I'm researching more out of my own sheer curiosity as to where the idea came from and how far it went. If anyone has any historical documentation of the idea feel free to post. Let's just keep this about the history of a certain idea and stay away from the practicalities of honing. Onto the translation:

In English:

"the stone intended for sharpening the razor must be hard, with a very fine, uniform and dense grain, because without these properties it can never produce a properly fine cutting edge.

some apply two or three stones of gradually increasing fineness of the korus one after the other; It is certain, however, that you can always achieve your goal on a single, very fine stone - perhaps with a little more expenditure of time - probably even to the advantage of the cutting edge, because you do not expose yourself to the need to first work through the roughness caused by the rough stone to devour the finer.

Others go even further by giving the successive stones a different shape. In particular, an experienced man praised the following procedure as being very beneficial: the first, sharpest stone (which can be an oil or a water stone) should be given a convex shape; just like that, but to a lesser extent, the second, who is a Levantic oelstein; only the third (last) stone has to be completely flat, and for this you choose a fine, hard slate of clay (blue whetstone) on which you always have to pull it off with water.

this method is efficient; because through the convexity of the first two whetstones it causes a successive thinning of the knife in the vicinity of the cutting edge, consequently means that at the end of the day the flat stone only produces exceptionally narrow facets and its work is completed quickly: I only believe that the machining on the convex stones will require even more skill than honing the already difficult task on a flat stone. In fact, as far as I know, the latter is found exclusively in use by knife manufacturers, knife sharpeners and barbers. "

In German:

"der zum abziehen der rasiermesser bestimmte stein muss hart, dabei vou sehr feinem gleichformigen und dichten korne sein, weil er ohne diese eingenschaften niemals eine gehorig feine schneide zu erzeugen vermag.

manche wenden zwei oder drei steine vou stufenweise zunehmender feinheit des korus nach einander an; es ist aber gewiss, dass man auf einem einzigen ganz feine stein - vielleicht mit etwas mehr zeitaufwand - jederzeit zum ziele kommt, wohl sogar zum vortheil der schneide , weil man sich micht der nothwendigkeit aussetz, die von dem grobern steine verursachten rauhigkeiten erst wieder durch den feinern zu vertilgen.

andere gehen noch weiter, indem sie den auf einander folgenden steinen auch eine verschiedene gestalt geben. namentlich ist mir von einem ertahrenen manne folgendes verfahren als sehr vortheilhaft geruhmt worden: man soll dem ersten, scharfsten steine (weicher ein oel-oder ein wasserstein sein kaun) eine konvex-gekrummte gestalt geben; eben so, jedoch in minderem grade, dem zweiten, der ein levantischer oelstein ist; nur der dritte (letze) stein musse gauz eben sein, und hierzu wahle man einen feinen harten thonschiefer (blauen schleifstein) auf dem das abziehen stets mit wasser zu geschehen hat.

rationell ist diese methode; denn sie bewirkt durch die konvexitat der ersten beiden abziehsteine eine successive verdunnuug des messers in der nahe der schneide, macht folglich, dass zuletz der flache stein nur ausserat schmale facetten hervorbringt und seine arbeit schnell vollendet: ich glaube nur, dass die bearbeitung auf den konvexen steinen noch mehr geschicklichkeit erforden wird, als das schon gennngsam schwierige abziehen auf einem flachen steine. in der that findet man den letztern, so viel mir bekannt, ausschliesslich im gebrauch bei den messerfabrikauten, messerschleifern und barbieren."