Thread: A second bevel added late.

Double bevels are a fun way to play with sharpening, they provide a shortcut in honing process. I think if you have regular honing down why not play with the double bevel. A double bevel can be a real time saver especially when honing a worn out wedge with large bevels.

I have added two layers of tape to the razor for the polishing hone on a variety of hones and razors. I have found that with as little as five strokes on a fine hone on the double bevel can make a really great edge.

It is not a big deal to get rid of the double bevel with a 4k hone.

I do not use a double bevel on every razor but it is a fun thing to try every now and then. I am usually looking for something to hone so the extra work is not an issue with me.

Charlie

Well, this morning I got a great shave off my ERN ator but I didn't use the double bevel method. Tonight I will polish some more with the coticule and use tape and see if there is any difference and if it's worth all the taping and remembering to tape.

Originally Posted by bjanzen

So in your experience, it added strength to the edge. That was my finding too. Also made up for poor ability. I still say try it and see for yourself. At this time, I am not doing it but I may try it again.

It adds to the angle which I assume needs to be a tad higher because of the steel. I used 3 layers of electrical tape.

Charlie said it. It's a shortcut.

With that progression described in the first post, you should be able to easily reach the physical keenness limit that the 12K is capable of. The Coticule will not add any extra keenness over a 12K edge, but will add its typical feel to the edge.

What a layer of tape does late in the honing procedure, is tipping the razor over on its very edge. A new, secondary bevel starts to grow, rapidly at first, slowing down as it grows wider. This happens because even a fine (finishing) hone removes steel effectively enough at a very narrow region. In case you have left behind some keenness during a previous honing step, a 12K finisher might not be capable in correcting that, and a Coticule on water even less. But cutting a secondary bevel, these hones have their own shot at refining the edge. And it's polished all at once.

One layer of tape is enough to unleash the potential of a double bevel. Two layers make it possible to start out at a less sharp level, and three layers even more. But the more tape you add the wider the edge angle becomes, which opens a whole new can of worms and food for discussion. Typical electric insulation tape has a thickness of 0.15milimeter. That raises the enclosed edge angle approximately 1 degree. In the Unicot method for Coticule only honing, I rely on one additional layer to get that clear shot at reaching the keenness limit. A Coticule with slurry leaves an edge that can hardly be called shaveready, and still one layer of electrical insulation tape is sufficient to get the desired result. So I don't really see the point in using 2.

But, bottom line: with your careful progression, I don't think you're leaving much keenness behind for the secondary bevel to improve upon.

Best regards,
Bart.

Not sure if this has already been mentioned, but mathematically, a double bevel is actually stronger than a single--it should not break down any faster. It's probably not enough of a difference for us to notice, though.

Originally Posted by Bart

In case you have left behind some keenness during a previous honing step, a 12K finisher might not be capable in correcting that, and a Coticule on water even less. But cutting a secondary bevel, these hones have their own shot at refining the edge. And it's polished all at once.

That's a great explanation of how it seemed to me.

Originally Posted by PA23-250

Not sure if this has already been mentioned, but mathematically, a double bevel is actually stronger than a single--it should not break down any faster. It's probably not enough of a difference for us to notice, though.

On the other hand, if Bart's right (and I think he is), then you actually do have a sharper edge overall, which may be sort of the same thing, at least in one sense.

My experience with using a microbevel at the 30k level was that I could then shave with the razor at a much lower angle - almost flat against my face. It follows that at lower angles the edge behaves as if it's "stronger" in terms of not dulling as quickly (an effect I definitely noticed).

If you like messing about with honing and have a beater razor, double bevels are fun. Try going from an intermediate grit hone (about 4k) then put on two layers of tape and go straight to the finishing hone.

I know that is a goofy thing to try, but I have had good results with skipping grits and going straight to the finishing hones.

I am not advocating this method, just attempting to provide entertainment for bored hone junkies.

Edit: I am not a total nut, I touched up a razor this evening with a couple 1-3's on the norton 4/8k then a chrome ox paddle strop. I just like to experiment.


Charlie

To me yes double bevels have strengthening merit in some cases (hi_bud's first post) but changing the angle from say 15 to 17 degrees is not THAT significant, so good (or rather, tough) steel won't need it. Steel can be good but brittle (the harder it gets the more brittle it gets- microchip, the softer it gets the more ductile it gets- losing an edge, so its a balance game in the tempering process)

I see it far more as a short cut for the experienced and an easy way out for people not doing it right. See below: The top two represent an edge that is sharp (but maybe slightly rounded, coticule with slurry for instance), being refined for whatever reason, (maybe a short cut to getting rid of the tiny round tip) sharpened by a pro. The bottom two represent an edge with a bevel not fully set that is "short cutted" to make up for bad low-grit honing by a newb.