Thread: Taping the EDGE

Originally Posted by Quick

I think that's what Russel said. ...

...Surely personal shave angle would be a factor as well. ...

It was, I was just agreeing with him. But now you've pushed me to try to figure out what the optimum angle of the blade should be relative to my face given each razors unique bevel angle. Damn! Just when I thought I was starting to get a hold of everything.

Quick, I understand what you're really looking for is a chart or some reference to the ratio of blade width to spine thickness and what angles the resulting ratios create. I swear within the last year I saw someone link to something like that. While Russel has shown with his great experiment that a range of angles can serve a razor well, blade width to spine thickness ratio can't be a completely arbitrary choice and expect that the resulting blade, if it looks like a razor will shave well. I wouldn't want to shave with an 8/8 1/16" thick spine razor nor would I want to shave with a 3/8 1/4" thick spine razor!

Chris L

Chris,

I think you're onto something. Each razor should have its bevel carefully measured, which factor then will be entered into a carefully empirically derived equation which will yield the exact angle at which the razor must be held to the face for optimal shaving. Any deviation from this proper angle will then automatically delete any requests for help from the august panel here in attendance. All calls for help must be prefaced with the dangle angle, which will be scrupulously noted and assiduously compared to the data carefully filed and held at angle central.

Yes, yes, an answer to yet another of life's nagging problems.

Exactly, Bruce. And...precisely! Finally, someone who understands me!

Chris L

Originally Posted by Chris L

Quick, I understand what you're really looking for is a chart or some reference to the ratio of blade width to spine thickness and what angles the resulting ratios create. I swear within the last year I saw someone link to something like that. While Russel has shown with his great experiment that a range of angles can serve a razor well, blade width to spine thickness ratio can't be a completely arbitrary choice and expect that the resulting blade, if it looks like a razor will shave well. I wouldn't want to shave with an 8/8 1/16" thick spine razor nor would I want to shave with a 3/8 1/4" thick spine razor

Ummm, no. No need for a chart. It's just triangle geometry. You have 3 sides and 3 angles. Given any 3 of those values you can solve for the other 3. If you want to know the bevel angle produced by your current blade width and spine thickness you can use SSS. If you want to know what spine width you need to produce a specific bevel angle you would use SSA to solve for the spine width (or, since 2 sides are equal, how much to take off your blade width ).

I had interpreted Russel's findings to be that most razors seem to be manufactured to produce a bevel angle within 12* and 22*. Further, that acceptable shaves are realized within that range. I think Russel also implied that when he went outside of that range that it was less possible to achieve an acceptable shave.

So that pretty much answered the question. 12* to 22* is, relatively, a large range.

I used my 5/8 Dovo Micarta as an example. It starts out with a 5/8" wide blade and a 5 mm thick spine which results in a 18.1* bevel. If one always taped the spine, the bevel angle wouldn't go out of this "acceptable" range until you had removed a full 1/8" of blade width from the edge (1/5th of the blade would have to be removed). Conversly if the spine width was lessened by a full 1 mm (without touching the edge of the blade) you would still be well within this range.

Conclusion: given that you start well within the acceptable bevel angle range, it would take a LOT of honing with disproportional wear to have a significant effect on shavability. ==> factoring the change in bevel angle over time, into the decision to tape or not to tape is probably not a consideration

Still useful information if one has a razor with a bevel angle close to the limits. Also useful if you might be trying to decide if a badly disproportional razor is worth restoring or not.

Now... (haha) since many are going to any lengths searching for the holy shaving grail... I was postulating that matching the bevel angle to your preferred shaving angle might bring significant results. I'm guessing that those who shave with a greater angle (spine away from skin) would do much better with a greater bevel angle. This would keep the surface of the bevel much flatter on the skin. Those with less of a shave angle would probably do better with less of a bevel angle. In fact, I'm guessing you would want the bevel angle to be the same as your shave angle (or visa versa).

Might explain why people are much more partial to some of their razors over others?

You're talking to a bunch of guys who think taking an extremely sharp razor to their throats is a good guy. Heretics are as welcome here as lunatics. : )

If you want to change your bevel by taping the spine, go ahead. Lots of guys do this for various reasons ranging from protecting the spine to putting a secondary bevel on the razor. This should not be a verboten topic and, as a lifelong honer, let me instead ENCOURAGE you to experiment with new techniques.

Breadknifing is an old technique. Read about it on my "Honing How To" page in an excerpt from a book written in 1908 by a Cornell professor of cellular biology. The excerpt is about honing microtomes which he says should be much sharper than razors . . . .

Originally Posted by Howard

You're talking to a bunch of guys who think taking an extremely sharp razor to their throats is a good guy. Heretics are as welcome here as lunatics. : )

If you want to change your bevel by taping the spine, go ahead. Lots of guys do this for various reasons ranging from protecting the spine to putting a secondary bevel on the razor. This should not be a verboten topic and, as a lifelong honer, let me instead ENCOURAGE you to experiment with new techniques.

Breadknifing is an old technique. Read about it on my "Honing How To" page in an excerpt from a book written in 1908 by a Cornell professor of cellular biology. The excerpt is about honing microtomes which he says should be much sharper than razors . . . .

Was his book applauded? or was he just deemed a lunatic.

Howard, as a lifelong honer give us your thoughts on bevel angle (generally speaking).

* Is there a range of bevel angles, outside of which an acceptable shave is unlikely?
* Do razor manufacturers design their blades for a particular bevel angle determined by spine thickness?
* Is there a different "optimal" bevel angle for different types of steel?
* Do you take the resulting bevel angle into consideration when deciding if a disproportional razor is restorable?
* Would matching a bevel angle to shave angle make a noticeable difference?

(I make a distinction between bevel angle and "sharpness")

Here's what I'm wondering about with shave angle.
Let's say you end up with a 15* bevel for whatever reason. Are you likely to get the best shave with a 15* shave angle?

*note: I think the graphic artist I commissioned was under the influence so it's not exactly to scale...

Those are great drawings! I would think that the middle 15/15 would be the best shave, with the last resulting in cuts and aggravation and the first leaving stubble.

so nobody cares to advance the theory that a blade with a 9 degree angle will cleave the hair easier than say the 18 degree?

although I would think the lesser angle will be most sharp
It may also have to do with the differences in facial hair between different people, some with thick hair, some fair and fine, and the fact that angle can be adjusted by a tip of the hand holding the razor, making slight angles changes pointless, somehow the human hand can tell the right angle by just feeling how the blade is cutting and adjusting "on the fly"!
each one will have that perfect angle, just got to find it!

My observations disagree with the ones expressed so far: I have 3 different razors: one 20 degrees, one 18 degrees, and one 15 degrees. The 15 clearly shaves better than the 18 (for both thick and fine hair), which in turns shaves better than the 20. The final result between the 3 razors is the same but what I mean is that the 15 shaves more effortlessly. BTW, the 15 degree razor in question is a 6/8 Beau Brummel with natural hone wear, it was 17 degrees when new.

So far the more extreme the angle, the smoother the shave. Next, I will try a 13 degree Dubl Duck. This is about as extreme an angle as you can go probably.