Micro-bevel specifics

EZ Bake · May 30, 2013

So I've got a Wicked Edge Pro kit (and added the ceramic 1200/1600 grit stones) and I have a few lighted loupes / handheld micro-scopes (25x, 45x, 60x) and I'm getting what I would call proficient at sharpening with this thing to a very clean primary edge with a good apex, but I've always had some pre-concieved notions about micro-bevels that I thought I would just verify on here (I searched this sub-section for answers, but didn't find all the info I needed).

If I start out with a 20 degree per side angle, I will typically move out to about 22 or 23 per side for the micro-bevel (pretty much all of my knives are between 18-22 degrees for the primary bevel). Is 2-3 degrees per side for the micro-bevel too much / not enough? I only want a little bit of extra edge-strength (or in the case of S30v, just a little longer retention over that one day or so of sharp edge - wearing into working edge). I seem to be getting good results, but I'm not sure if I could be getting better results.

This leads me to my next question:

How much material should I be taking off when adding a micro-bevel? I've read and watched videos where folks just use 5 micron or 3.5 micron strops (or 1600 grit Ceramic) to add the micro-bevel (with maybe 20 or so very light strokes). Is this enough? I've tried it with just one strop or ceramic stone, and I've tried using both the 1200 and then 1600 ceramic stones and then the 5 micron and then the 3.5 micron (just a few light strokes with all 4), but I think that's too much for just a micro-bevel. How much material do you generally remove to get just a micro-bevel (ballpark estimate in terms of grit/micron and what stones, and what number of strokes)?

Should I be able to see the micro-bevel in a 25x Loupe? In a 45x scope? In a 60x? I feel like in some cases, I'm doing too much, but in others I'm not doing enough to make a difference (I don't seem to be able to tell the difference in edge-performance - but I'm not doing any scientific tests or anything - just normal everyday use).

Magnaminous_G · May 31, 2013

You should be removing very, very little material. A real micro bevel is just that: micro. Use a finer (higher grit) stone than your last finishing stone. Very light and careful alternate passes at a slightly higher (more obtuse) angle than your primary bevel angle, maybe 5 strokes on each side. Then you have a micro bevel.

As to your question about loupes, you can see anything with a 20X loupe. I personally like the Peak brand 22X. Very, very nice loupe. You start to see things at 20X that you can't see at 10X or 15X. But going much higher than that is pointless, imho. With 20X, you can see the tiniest bits of burr and stuff like that. Plus, the higher the magnification of the loupe, the exponentially more expensive good glass costs. Very few people will drop the $$ necessary to get good quality, coated glass at that magnification.

EZ Bake · Jun 5, 2013

5 strokes seems even lighter than I've heard/read - is that really all I need? Are Ceramic stones (1600 grit) good to use, or should I be skipping that and just using a leather strop w/paste?

Magnaminous_G · Jun 5, 2013

If you use a loaded strop, then you won't be making a micro bevel. You'll be stropping. And yes, 5 strokes... 5 light strokes. Yes, ceramic stones are great for micro bevels because they are so hard. As for whether you should skip, I say, "Yes." I know how to do a micro bevel, but I don't like them. A freehand V-edge has subtle convex in it, and I just don't see the point of a micro bevel. But I guess I sometimes put a micro bevel on an edge if I raise the angle slightly during burr removal, but it's very, very subtle since it's usually just the last pass or two. It's all good.

EZ Bake · Jun 14, 2013

Here's another stupid question - is 1600 grit Ceramic fine enough or should I be using a finer stone (or lapping paper at a higher grit taped over the stones)?

Sadden · Jun 14, 2013

If you like the edge you are getting then it is fine enough. But as always we always want it just a litttttttttle bit sharper

Twindog · Jun 14, 2013

I doubt that you need a micro-bevel with S30V at 20 degrees per side.

My sense is that most people who strop are actually creating a tiny convex micro-bevel. It takes very good technique to properly strop a V edge, especially with a soft backing, without creating a convex micro-bevel. If that's what you are doing, great. That extra degree or two you're trying to get with stropping is actually the rounding of the V apex into a less acute convex edge.

A regular micro-bevel created with a stone -- such as with the Sharpmaker's 15/20 dps bevel system (40-degree edge with a 30-degree back bevel) -- follows the same rules as a regular V edge in raising and removing a burr. How much extra protection your edge receives from this micro-bevel depends on how wide the micro-bevel is at the shoulders. The more you sharpen the micro-bevel with the stone, the wider its shoulders. As the shoulders get wider, the edge becomes more robust and cuts less well. At that point, you'd re-establish the primary edge (back bevel) and start over with a narrow edge (micro-bevel).

EZ Bake · Jun 17, 2013

Twindog said:
I doubt that you need a micro-bevel with S30V at 20 degrees per side.

My sense is that most people who strop are actually creating a tiny convex micro-bevel. It takes very good technique to properly strop a V edge, especially with a soft backing, without creating a convex micro-bevel. If that's what you are doing, great. That extra degree or two you're trying to get with stropping is actually the rounding of the V apex into a less acute convex edge.

A regular micro-bevel created with a stone -- such as with the Sharpmaker's 15/20 dps bevel system (40-degree edge with a 30-degree back bevel) -- follows the same rules as a regular V edge in raising and removing a burr. How much extra protection your edge receives from this micro-bevel depends on how wide the micro-bevel is at the shoulders. The more you sharpen the micro-bevel with the stone, the wider its shoulders. As the shoulders get wider, the edge becomes more robust and cuts less well. At that point, you'd re-establish the primary edge (back bevel) and start over with a narrow edge (micro-bevel).

So is 20 degrees per side too obtuse for (Spyderco's) S30v?

Should I stick with Ceramic stones for a micr-bevel and leave the strops for only the primary edge then?