Convex angerichtete Steine

[sl]

TSS definiert "keen" und "sharp" gegensättlich zum ScienceofSharp.

Und wie definiert er es dann? Ich komme nicht dahinter, wie er es meint.

Sharp ist klar, bei keen ist Hautfreundlich gemeint, oder nicht?

So hab ich es für mich auch mal übersetzt, als ich zum ersten mal auf dieses Begriffspaar gestoßen bin. Das aber eher weil ich es gleichgesetzt habe mit der hierzulande geläufigen Diskussion entlang des Begriffspaars "scharf - sanft".
Inzwischen vermute ich aber, mit "keen" ist nicht das Gefühl der Rasur auf der Haut gemeint (also "sanft")sondern ein Zustand der Klinge in Abgrenzung zu "sharp". Das neue Jahr beginnt, wie das alte endete: Fragen über Fragen!

 

[Philipp78]

Und wie definiert er es dann? Ich komme nicht dahinter, wie er es meint.

Nachdem ich verstanden habe, TSS definiert „keen“ die Schneide mit dem flacheren Facettenwinkel (in der Nähe der Schneidkante) und als „sharp“ gilt bei ihm die Scvneidkante mit der dünnsten Kantenlinie.

 

[JPO]

Hi all. I have been following this topic on several forums lately.
I have convex a few stones and tried the concept of creating a concave bevel, and thinning the edge. There is an old German text book that speaks about this.
Is anyone interested in doing some translation? Google does a poor job

 

[JPO]

It seems like i am not allowed to put in links to the book. Here is the front page.

 

[Geier0815]

Ok, to translate the text you need someone who can write an english that was spoken appr. 100 years ago. My english is very lousy but I will try to explain what the part with the convex sharpening stone says:

A man, who the author think he is an expert, says that the best way to sharpen a razor is to use 3 stones where the coarsest has an strong convex surface, the middle stone an light convex surface and the finest stone an straight surface. There is no explanaition why the man think this. Everything the author writes about an possible reason, makes no sense at all. On the other hand the author think that this kind of stone-setup will make it more difficult for a normal user to get good results, because normal grinding is difficulty enough and such a setup will make it more complex with no need.

Maybe another user can give you a better translation...

 

[JPO]

Ok, to translate the text you need someone who can write an english that was spoken appr. 100 years ago. My english is very lousy but I will try to explain what the part with the convex sharpening stone says:

A man, who the author think he is an expert, says that the best way to sharpen a razor is to use 3 stones where the coarsest has an strong convex surface, the middle stone an light convex surface and the finest stone an straight surface. There is no explanaition why the man think this. Everything the author writes about an possible reason, makes no sense at all. On the other hand the author think that this kind of stone-setup will make it more difficult for a normal user to get good results, because normal grinding is difficulty enough and such a setup will make it more complex with no need.

Maybe another user can give you a better translation...

Thank You. That was my understanding as well.
I convexed three of my stones just to test it out on an Dovo razor. I used a 800 Naniwa, a 3k Naniwa pro and a coticule that had a little larger radius. I finished on a flat stone.
I felt the edge got more flexible, and seemed to cut a little better. I do think you need to be careful to avoid getting a edge that is to thin. This razor also had some geometry problems. It was in my experience easier to hone on a slightly curved surface to get even wear and contact.

 

[JPO]

This is what i got from the text when i first tried to understand it. I am Norwegian, so there is more then one way i could get this wrong It seems that even you German speaking people have a hard time

The stone intended for sharpening razors must be hard, very fine and have a uniform and dense grain structure, because without these properties it will newer be able to produce a properly fine cutting edge. Some use two or three stones of gradually increasing grain fineness one after the other, but you can certainly use a single very fine stone, which maybe requires expenditure of more time, but always come to the goal, probably even with an advantage to the cutting edge, because you do not need to erase the damage done by the coarser stone with the fine stone.

Others go further by giving the stones following one another a different shape. In particular, the following procedure from an experienced man is very advantageous.
You should give the coarsest stone a convex/curved shape, the next one to a lesser degree. Only the third (last) stone must be completely flat.

I just think that honing on the convex stones will require even more skill which is even difficult enough on a flat stone.

 

[JPO]

This might explain why the sharpening can get more complicated, especially if you only shape the stone on one axis.
You can end up with an uneven bevel. This is to some extent compensated by if you have a curve in both axis. If you approach the stone (stein) from an angle, you can end up with a different effective angle, because you have a different contact point on the spine relative to the cutting edge (end terminus)

 

[JPO]

This is just to get some numbers to it, which i found interesting.
I might learn some German along the way

Dies ist nur um einige Zahlen dazu zu bekommen, die ich interessant fand.

 

[JPO]

An old German grinder called the concept the opposite of tape. If you look at the picture you can see the the flat final stone only works on the lower part of the bevel (end terminus)

 

[Hellas]

An old German grinder called the concept the opposite of tape.

Anyhow, what I see on the picture looks quite the same to the effect when using tape (or one layer more tape) on the finisher (like Setting a second bevel) Or am I wrong?

 

[JPO]

Anyhow, what I see on the picture looks quite the same to the effect when using tape (or one layer more tape) on the finisher (like Setting a second bevel) Or am I wrong?

You are correct, but no tape have been used. Tape changes the bevel/facet angle by around 0.9 deg on a 7/8 razor. So you are able to keep the original steeper angle and at the same time get a little secondary bevel effect. This can give a cleaner edge. It also speeds up the process. Win win if you ask me.
Without getting into the Dovo edges. This is also what happens with the spinning disk, because it is not flat, and they approach it at an angle. You then get a slightly taller bevel, which makes it more flexible.

The deflection and flexibility of the bevel is to some degree governed by this formula:

L designates the length of the bevel, and is raised to the power of 3, which means that a small change will make a big difference in the flexibility.
Think of P as your hair pushing against the edge. You are not shaving like this, but that is not the point.

In I in the denominator d, which denotes the bevel thickness is also raised to the power of three. If this is reduced by a small amount you will have an effect.

When you combine these two factors you will notice a difference. If this difference is something you will benefit from, you have to decide for your self.
Flexibility alone does not get you anywhere, you also need a small radius at the apex, and the edge needs to be able to hold that shape.

 

[Hellas]

So you are able to keep the original steeper angle and at the same time get a little secondary bevel effect

Indeed. But for my beard I found out that a more obtuse angle and secondary bevel (at full-hollow-grounded Solingers) shaves me quite more comfortable than the "original" acute angle and keeps my blades longer sharp

 

[JPO]

Indeed. But for my beard I found out that a more obtuse angle and secondary bevel (at full-hollow-grounded Solingers) shaves me quite more comfortable than the "original" acute angle and keeps my blades longer sharp

That is the case for me to. It can be a bit to much. But it is fun to play with. My face likes a smoother edges. Even a coticule edge can be greate.
Make it simple. It is just interesting to try to understand what these old German grinders from Solingen was talking about. Maybe this is something you all new all ready.
I also think it works best with hollow ground razor, because of the flexible grind.
I had a really bent Dovo razor that was easier to hone on a curved surface.
Now i think i have a better understanding, but most of my razors are honed on flat stones.
Not better, just different.
I tend to overthink stuff to much.
It is good to hear that dovo is now back in business again, carrying on the traditions.

It seems like Böker now is grinding all their razors to an extra hollow ground. Those are thin enough as they are. I have one, but i think i prefer the regular full hollow 6/8 blades.

Tank you for not biting my head off. I am not here to prove anything.

 

[Eisenkopf]

Wird es am Ende eine deutsche Zusammenfassung geben?

 

[Leiche]

ich denke nicht

versuchs mal damit

Google Übersetzer

Mit diesem kostenlosen Google-Dienst lassen sich Wörter, Sätze und Webseiten sofort zwischen Deutsch und über 100 Sprachen übersetzen.

translate.google.com

 

[j0mber]

versuchs mal damit

na wenn schon, dann ein deutsches Unternehmen https://www.deepl.com/translator - ist in vielerlei Hinsicht besser als der google translator

 

[j0mber]

Man könnte auch noch den wissenschaftlichen Diskurs über "sharp vs. keen" mitanführen. @JPO For that kinda stuff check out https://scienceofsharp.com/2015/03/24/sharp-and-keen-part-2/ and part one as well.

Für mich ist das ein schön spannendes Thema, wo man richtig ins Detail gehen kann, doch nimmt das des öfteren Auswüchse an, wo ich mir wirklich denke, dass das echt nicht sein muss. Als würde man jemanden den Kopf abbeißen, nur weil er eine Meinung zum Rasiermesser honen hat.
Es ist doch wirklich egal, wie man sein Messer jetzt so hin bekommt, wie man es mag. Hauptsache es rasiert so wie man es haben will. Man kann über wirklich jedes kleinste Detail streiten, doch wird dann wieder oft vergessen, dass sehr vieles nicht einfach so allgemein gesagt werden kann.
Für manche Menschen ist ein RM vom 10k Naniwa super toll und rasiert genau so wie sie das möchten.
Für andere ist der 10k bzw. generell eine Schneide vom Synthie überhaupt nicht angenehm.
Für wieder andere ist ein convexer Naturstein das beste. Und andere finden, dass man einen Stein gar nicht abrichten muss, wenn er denn eingearbeitet ist.
Soll doch alles so sein, hauptsache man hat Spaß an der Rasur. Letztlich ist das eh nur verschwendete Lebenszeit, die man viel lieber ins Rasurutensilien akquirieren stecken sollte

 

[Rotznase]

Ob es allgemein Üblich war einen konvexen Stein für den Abzug zu nutzen ist fragwürdig. Es mag vielleicht den einen oder anderen Schleifer gegeben haben, der konvex geschärft hat, die Regel war es eher nicht.

Auszug aus Max Schmidt's Buch "Das Rasiermesser":

​

Anders sieht es beim Reparatur-Schliff aus, dort wird ein runder Stein eingesetzt um die Hohlung vom Wall zur Schneide hin zu erneuern.

Gruß
Michael