Thread: The perfect bevel..

Two questions keep coming to mind and I am hoping for clarity..

- I have a few razors that have fairly wide bevel. I always hone with tape, typically 7 or 8 mil Scotch. I understand basic geometry of the blade width and spine width and know the width of the bevel is a function of these components, plus the added spine width resulting from the tape. If the razor takes a good set, and hones & shaves well, should the ultimate width of the bevel be of concern?

- Along similar lines... I've had a few blades that resisted a good bevel until a second (or third) layer of tape was added. When this is the course of action, it might require a sizable amount a steel be removed in order to avoid a double bevel. I have been reluctant to waste this steel and in a few cases just left the double bevel thinking it will remedy itself over future honings. The double bevel doesn't seem to adversely impact the quality of the shave or longevity of the edge. So, is there harm in a double bevel and if yes, what it is the issue?

Regarding the first point, bevel width is determined more by the grind than geometry i.e. two blades with the same geometry, one almost wedge and the other full hollow, wil have very different bevel widths.

As for a secondary bevel, don't worry about it - some people encourage it. If you take a look at the Coticule.be site, you will see an article on secondary bevels.

Nothing wrong with a secondary or micro bevel, some believe, it is a stronger bevel as the actual angle is fatter with more steel behind it.
And some, mostly tool folks who hone a lot, daily in some cases, see it as a waste of steel to correct, just for appearances.

If you continue to hone with the same amount of tape, eventually the secondary bevel will become the primary bevel.

While I can see how the grind could alter the width of the bevel, by altering the thickness of the edge steel without changing geometry.

Intentionally altering geometry by changing the thickness/height of the spine, does affect the width of the bevel, as we easily see by adding tape. Altering either of these two points in thickness and will affect the width of the bevel.

Don’t know if changing the grind, changes the bevel width more… as so few of us do re-grinds and compare bevels.

How a bevel looks, single or double bevel, thick or thin, has nothing to do with how it shaves, it’s the edge that matters and in extreme cased, the angle, which is really pretty forgiving.

Originally Posted by Euclid440

Nothing wrong with a secondary or micro bevel, some believe, it is a stronger bevel as the actual angle is fatter with more steel behind it.
And some, mostly tool folks who hone a lot, daily in some cases, see it as a waste of steel to correct, just for appearances.

That's what I was feeling.. Unless there was a strongly compelling reason to do away with the original bevel (and it doesn't sound like there is) why waste the steel?

Originally Posted by Euclid440

If you continue to hone with the same amount of tape, eventually the secondary bevel will become the primary bevel.

Exactly my thoughts. Truth told, it's not a matter of aesthetics unless using a loupe, so doesn't bother me and I know over time it will remedy itself.

Originally Posted by Euclid440

How a bevel looks, single or double bevel, thick or thin, has nothing to do with how it shaves, it’s the edge that matters and in extreme cased, the angle, which is really pretty forgiving.

That's precisely the what I was looking for. Thank you. I am sure there is some esoteric geometric relationship that gets a little screwed up, but my face can't feel it..

Thank you!

I like the concept of this conversation and would like to see what everyone thinks.

Bevels can become wider because of the amount of pressure being used in honing. I don't use any pressure, and my bevels are sometimes difficult to see unless I use a loupe.

The matrix for determining bevel angle asks for spine width and the size of the wear to determine the length of the blade as well as how many layers of tape. It does not however ask for the grind of the blade. So wedge, half, full or extra hollow will have the same bevel angle if everything else is the same.

I was encouraged to ask these questions after touching up two blades.. Most of my bevels are wide enough to be visible without a loupe. But with the Tim Zowada 2H2H one can't see the bevel unless magnification is used. The 2H2H is an incredible shaver and I wonder how much the fine bevel on it's own contributed to the shave. I have many other blades that provide equally good shaves with a wider bevel.

To reduce the thickness of the bevel, additional layers of tape could be used. That changes the geometry of the bevel.. There-in is the question...

Smaller bevels would meant he edge will be refined faster. You can do the same with a larger bevel with more strokes

'Good questions, Mike. If I understand correctly, your last post asks if the change in the geometry that goes w/ adding tape is an issue. I think the short version is no. The range of angles that successfully shave is pretty broad. This is perhaps illustrated by all the old heavy Sheffields that show little or no spine wear. The absence of wear has to mean something was placed on the spine while honing. Sixgunner had a thread a year or so back on. As a default position - always believe a face. It the shave's good - all the other stuff is just vanity.