Thread: That shaped hone...

That's right but there is a.reason. to sell the convexed stones and lapping plates. Nothing more. Many people heard about this already. It's just rehashed in a different way because the bullsrush method of "your stupid and I know everything" only succeeded in getting him thrown and laughed out of most forums.

I wouldn’t give jarrod the air he breathes so no I give him no credit he’s a Chod

This is an old text relating to times when hollow grinding hadn't been found out yet. Wedge shaped blades used to be hollowed to some extent to make sharpening possible.
Jean Jacques Perret describes the same procedure in 1770 in his book "Pogonotomie ou l'art d'apprendre à se raser soi-même".
He describes the use of a grinding wheel followed by a hone.

For those who read French: page 34 of this document:
https://books.google.de/books?id=1ix...page&q&f=false

M. Perret recommends a grinding wheel (une meule) is used every so often to create a hollow bevel. He recommends a bevel that will bend slightly when you push it against your thumbnail. He recommends a bevel width of 1/2 to 1 "ligne". A ligne being 2.26 mm.

First time I've seen old publications referenced regarding convex hones. Interesting.

Originally Posted by Kees

For those who read French: page 34 of this document:
https://books.google.de/books?id=1ix...page&q&f=false

M. Perret recommends a grinding wheel (une meule) is used every so often to create a hollow bevel. He recommends a bevel that will bend slightly when you push it against your thumbnail. He recommends a bevel width of 1/2 to 1 "ligne". A ligne being 2.26 mm.

Originally Posted by Kees

This is an old text relating to times when hollow grinding hadn't been found out yet. Wedge shaped blades used to be hollowed to some extent to make sharpening possible.
Jean Jacques Perret describes the same procedure in 1770 in his book "Pogonotomie ou l'art d'apprendre à se raser soi-même".
He describes the use of a grinding wheel followed by a hone.

Exactly, this is what he is talking about, hollow grinding the edge.



When talking about razor sharpening, he makes a reference to figures 2, 3, 5 & 6.

Anyone know where these are to be found? It would add a lot to the story, but I can't seem to find them?


Also, he's talking about razor sharpening, BUT when a razor is having trouble to get sharpened or needs to be sharpened very frequently, THEN to go to a 'meule' / grindstone as a possible solution. But that one has to be very careful here, because a good razor can very easily get messed up by different factors of the meule.


Otherwise as I read it, he's been talking about regular honing on regular stones.
To do even strokes of the entire length of the razor with very little pressure.

I'm not seeing anything convex being talked about, only about the hollowing out the edge of a blade more. But not that this is done by convex stones.
And that it must pass a thumbnail rolling test, just like with scythe blades, it's just about thinning out the edge of the blade.

Which incidentally is what a convex stone does, but not at all done in the same way. And no mention of it, either.

I also have a good feeling he's talking about trouble razors with bevel angels that are way off, like you often see on thicker wedge grind razors that need at least 1 or more layers of tape to hone. Grinding would be another option, as they didn't use tape back then, he does mention to go to a grinding stone here.

Or he's talking about razors where the grind is thick and take "too" long to sharpen.
Knowing that spine wears quicker than the edge, that could create all sorts of problems and inabilities in the traditional and regular ways of honing.

I haven't read the entire document, yet but I will. I see it again more as a solution to a problem rather than a standard sharpening practice, problematic razors.
And the solution is a re-grind; and some people apparently use convex stones nowadays, but nothing about convex stones I see being mentioned in the document.

It's hollow grinding avant la lettre !
Probably what eventually lead to the discovery of a true hollow grinding.

A meule is a convex stone by definition as it is round. Many here use tape when honing true wedges. Both serve the same purpose.

When flat polishing hones can no longer sharpen the razor Perret recommends a grinding wheel (=meule) to keep the bevel at a width of 1.13-2.26 mm (1/2-1 ligne).

I guess Perret would recommend that this razor be put on a grinding wheel to narrow the bevel to the sizes mentioned above: https://holli4pirating.wordpress.com...p-carousel-165

Here are the pics.
https://gallica.bnf.fr/ark:/12148/bp....item.r=figure

Originally Posted by Kees

A meule is a convex stone by definition as it is round.

Here are the pics.
https://gallica.bnf.fr/ark:/12148/bp....item.r=figure

yeah, true.

Thanks for the pics.

A regrind has nothing to do with common honing, that is what is being referenced, there are a few ways regrinds can be done by hand, we just happen to do them on Belt Grinders now because we can, and we have Electricity

Regrind

Originally Posted by gssixgun

A regrind has nothing to do with common honing, that is what is being referenced, there are a few ways regrinds can be done by hand, we just happen to do them on Belt Grinders now because we can, and we have Electricity

You're right: this is not honing but rather part of routine edge maintenance in those days, the days of solid wedge razors and no electricity tape.