Multiple bevels – which grit to drop down to?

[Jamey Howard]

If you’re creating more than one bevel, how do you know which grit to drop back down to when you widen the angle for the next bevel?

So for example, let’s say you’re doing the first bevel at 15 degrees per side (30 inc) and then you’re going to do the cutting edge at 18 degrees per side (36 inc).

You set the arms to 15 degrees and then go up through the stones finishing at the 1000 grit diamonds (side question – do you bother to strop this bevel or only strop the cutting edge at the end?). Now it’s time to do the 18 degree edge so you set the arms. At this point do you go all the way back to 100 grit? Do you only need to use the 800 / 1000 grits? Do you go back a little but not all the way to 100, say to 600 maybe?

How do you know?

[cbwx34]

When I go to the higher angle, I only use the finest stone I want to finish the edge with, then strop if desired. You’ll establish the bevel quickly, even with a ceramic stone. No need to drop down in grit, unless you want to create a stronger edge. So, in your example, I would set the 18 deg. bevel with the 1000g stone, and you’ll do it in just a few strokes.

No need to strop at the 15 deg. angle, unless you’re trying to polish the bevel out.

[Jamey Howard]

Thanks Curtis, nice and simple. I do have one follow-up question with regard to this point you made:

No need to drop down in grit, unless you want to create a stronger edge.

I thought that having extra bevels was usually stronger than one bevel? Or is that wrong?

EG let’s say you have two identical knives and both have their cutting edges set at 18 degrees per side. The only difference is that one has a simple single bevel at 18 degrees per side, and the other has a double bevel with the first at 15 degrees per side and then the cutting edge itself at 18 degrees per side, I thought the knife with the double bevel would be the one with the stronger / more durable edge? I may be completely mistaken however.

[cbwx34]

You’re right… sorry I didn’t make it more clear. What I meant was, say you did a knife at 15/18, and still had some issues with the edge “failing” for whatever reason. So, when you sharpen it again, you could keep the 15/18 angles, but spend a bit more time, or drop down a grit first, so that the 18 deg. bevel is better established, and will hold up better.

[Jamey Howard]

Thanks again Curtis.

Apologies, but once again I’m going to use the “two identical knives…” analogy here just to make sure I understand. So if we have our two knives and they both have double bevels at 15/18 degrees, however on one knife the 18 degree section is larger than on the other knife, then the one with the larger 18 degree section will be stronger?

If so then how come you can’t follow that through to its logical conclusion and say that if you enlarge the 18 degree section to the max it’s even stronger? Which would basically bring us back to saying a single bevel at 18 degrees is stronger than a 15/18 double bevel, wouldn’t it?

[cbwx34]

Yes… but one of the theories of doing microbevels is that you can have a thinner knife that will cut better… with a stronger edge.

[Mark76]

Yes… but one of the theories of doing microbevels is that you can have a thinner knife that will cut better…

Agreed

with a stronger edge.

Here I disagree (in the context of this threat). Like Jamey said, just follow the “logical conclusion”.

Be aware though, who you say this to. I got boo-ed and ppl were ready to break out the tar and feathers :cheer: .

Molecule Polishing: my blog about sharpening with the Wicked Edge

[cbwx34]

Yes… but one of the theories of doing microbevels is that you can have a thinner knife that will cut better…

Agreed

with a stronger edge.

Here I disagree (in the context of this threat). Like Jamey said, just follow the “logical conclusion”.

Be aware though, who you say this to. I got boo-ed and ppl were ready to break out the tar and feathers :cheer: .[/quote]

Well, it doesn’t make it weaker……. 👿 :silly:

[Johpe]

To try to throw a little bit more gasoline on the potential fire here (or actually just to get your opinions on this), which is the strongest and weakest of an edge with only 18 degrees, an edge with 15/18 degrees and an edge with only 15 degrees?

My assumption would be in the order I wrote them;18 strongest and 15 weakest and 15/18 in between.

[Mark76]

Johpe, I did a blog post on a related subject: convex edges (the one I got boo-ed for, so be aware). You can read it at http://moleculepolishing.wordpress.com/2013/01/24/what-is-the-use-of-a-convex-edge/ .

My conclusion: you’re completely right.

Maybe this picture says it all:

Molecule Polishing: my blog about sharpening with the Wicked Edge

[cbwx34]

To try to throw a little bit more gasoline on the potential fire here (or actually just to get your opinions on this), which is the strongest and weakest of an edge with only 18 degrees, an edge with 15/18 degrees and an edge with only 15 degrees?

My assumption would be in the order I wrote them;18 strongest and 15 weakest and 15/18 in between.

My conclusion: you’re completely right.

Isn’t that what I said?????????? :unsure: :whistle:

[Mark76]

Isn’t that what I said?????????? :unsure: :whistle:

Of course you did! We mods always agree and draw the same line. :dry: 😆 I must have misunderstood you. But, as you know, this topic has become a rather sensitive one for me 😉 😛 .

Molecule Polishing: my blog about sharpening with the Wicked Edge

[cbwx34]

Well, just for a bit of clarity… adding a microbevel to an edge is a bit different then the convex vs. flat bevel picture you posted, right? I agree with the diagram you posted… just don’t think it applies here.

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