Looking at "Vivi edges" with a VHX-6000 digital microscope

[Holland]

Very cool thread, thanks Vivi. I am interested in seeing more photos as well.

I personally use 600 grit when sharpening

[vivi]

Compared my user Pacific Salt sharpened at 200 grit to a NIB Pacific and a razor blade:







I'll be uploading 15-20 images when I get back to my laptop. These are higher quality and more interesting edges, you guys will like this update.

Here's a video of the 200 grit edge shaving pretty cleanly - https://vidsli.com/watch/97wjfM3gE6

`

What's the angle of that user bevel? Around 12º? It's a very nice edge.

I dunno. Here's a video where I tried to show my usual sharpening angle: https://vidsli.com/watch/vHPaW4BZYb

ill rig up a goniometer someday.

[vivi]

Session #2

First I have a fresh razor from Harry's.



Brand new and able to cleanly shave as expected.




Very clean, refined apex. The only imperfections appeared to be lint or oil. This is exactly the type of edge you'd expect to see on a razor blade, no surprises.


Now, on to the Pacific Salts.



First we have my daily user Pacific Salt 2 sharpened to around 10-12 degrees per side. I sharpened it right before looking at the edges, using a 200 grit diamond stone, the coarsest side of the 4 sided harbor freight stone.

Despite the coarse finish, the 200 grit edge can easily shave. Obviously the smoothness of the shave cannot compare to the razor, but it demonstrates the apex can be refined to shaving sharpness even at 200 grit.



This is a brand new Pacific Salt 2. As you'll see, the factory edge appears to be applied with a medium grit belt, then the apex is finished with a buffing machine. This knife also readily shaves, which is expected from a Spyderco factory edge.

First I want to compare something that surprised me. The tips.

Pacific User:



Pacific NIB:



As you can see the NIB one looks completely rounded off, while my user doesn't look much better. Both are perfectly functional feeling tips in use, easily penetrating plastic wrap etc.

Now let's look at the ricasso area, something I've never paid much attention to when observing knives under magnification:

Pacific User:



Pacific NIB:



I found this comparison interesting because the NIB edge looks kind of ragged like my 200 grit edge.


Before we compare the apex side by side, let's take a look at the scratch pattern on the bevel.


Pacific User:



Pacific NIB:



You can see the used one has much deeper scratches. They're also at a different angle.

I don't think the angle of the scratch pattern matters much on a polished edge. With coarse edges, however, it influences how efficiently the blade cuts using a pushing or pulling motion while slicing.

Now let's compare their apexes side by side.

Here's four of the NIB Pacific, two from the show side, then two from the back side.

Pacific NIB:







Now the 200 grit edged user.

Pacific User:




These first two images show what first appeared to be small chips to me. Presentation side is first, then the back side. This must be from some of the larger diamond grits on my sharpening stone, because this is a fresh, unused edge.

Here are some more images of the user, presentation side first, then back side.










Hope you enjoyed this round of images! I'm happy about these coming out a little clearer, and I think having a NIB version of the same knife made for an interesting comparison.

[cabfrank]

Really incredible. Thanks.

[metaphoricalsimile]

That NIB edge near the ricasso doesn't look like a rough edge, it looks like a burr. I'm guessing the finishing process wasn't able to hit that spot to clean it up.

[Coastal]

Excellent and interesting photos! I'm curious how the Vivi-edged user and the NIB compare from a cutting standpoint. Of course it wouldn't be head-to-head because of the difference in bevel angles.

[JRinFL]

Thanks for taking the time to post this.

[vivi]

That NIB edge near the ricasso doesn't look like a rough edge, it looks like a burr. I'm guessing the finishing process wasn't able to hit that spot to clean it up.

Taking a closer look I think you're right. Looks like the remains of a burr.

[vivi]

Excellent and interesting photos! I'm curious how the Vivi-edged user and the NIB compare from a cutting standpoint. Of course it wouldn't be head-to-head because of the difference in bevel angles.

With both edges fresh the NIB would be superior for push cutting and the user better on a slice. The user would have a geometry advantage that would reduce pressure needed to cut stiffer materials and help extend edge life.

Which edge would be best depends on the application.

[JSumm]

Thanks for posting Vivi! Very interesting. The low grit does look like small serrations and directly correlate to the use you have experienced.

[Manixguy@1994]

Thanks vivi ! Great pics and educational tool .Dan

[JonLeBlanc]

What an interesting thread!

[vivi]

First we have my daily user Pacific Salt 2 sharpened to around 10-12 degrees per side. I sharpened it right before looking at the edges, using a 200 grit diamond stone, the coarsest side of the 4 sided harbor freight stone.

the coarse finish, the 200 grit edge can easily shave. Obviously the smoothness of the shave cannot compare to the razor, but it demonstrates the apex can be refined to shaving sharpness even at 200 grit.

Carried this knife every day since this post. Have not touched up the edge at all. Despite cutting a lot of cardboard, parts of the edge still shave over two weeks later.

[JRinFL]

My theory is that the coarse edge acts similar to the fluting on Greek columns. It increases the strength and stability by increasing the surface area. Addition by subtraction, as it were.

[Mugman16]

do you strop after a coarse edge or does that ruin the point of it

[vivi]

do you strop after a coarse edge or does that ruin the point of it

I don't typically.

You can strop with these types of edges but you want to only do it 1-2 times per side tops.

Polishing the apex too much will ruin the teeth. But polishing a tiny bit can help enhance push cutting without completely removing the teeth.

Sometimes I give my chef knives one extremely light pass on an UF rod after setting the edge at 300 grit.

[Big John]

do you strop after a coarse edge or does that ruin the point of it

I don't typically.

You can strop with these types of edges but you want to only do it 1-2 times per side tops.

Polishing the apex too much will ruin the teeth. But polishing a tiny bit can help enhance push cutting without completely removing the teeth.

Sometimes I give my chef knives one extremely light pass on an UF rod after setting the edge at 300 grit.

This is extremely good advice. Also mirrors what I have done for many years. For my uses, performance largely comes from aggression, not sharpness. I discovered the wonder of stropping only about 5 years ago, and while it is extremely useful in some applications (with some wood and diamond compound, for hardly any money spent I can achieve ultra sharp mirror polished edges extremely similar to those yielded by half a dozen extremely fine waterstones for wood carving), when it comes to EDC, the (leather) strop is more used for burr detection than anything else.

[vivi]

That's how I generally use my strops too. burr detection mostly. i also use them to touch up my disposable razors before I switch blades. they're nice for extending their life a bit.

I've gotten away from relying on strops and higher grit stones to refine the apex. Instead I focus on using the light strokes I can when finishing an edge. I also stop after every single stroke to check for a burr when doing my final strokes.

Putting extra focus on minimizing the burr as much as possible has gotten me from barely scrape shaving to genuine hair popping sharpness off 300 grit diamond stones. Previously I did not think that level of sharpness was possible off that stone.

Your remark about cutting ability being tied to aggression more than pure sharpness rings true. I've experienced the same thing.

[Mugman16]

That's how I generally use my strops too. burr detection mostly. i also use them to touch up my disposable razors before I switch blades. they're nice for extending their life a bit.

I've gotten away from relying on strops and higher grit stones to refine the apex. Instead I focus on using the light strokes I can when finishing an edge. I also stop after every single stroke to check for a burr when doing my final strokes.

Putting extra focus on minimizing the burr as much as possible has gotten me from barely scrape shaving to genuine hair popping sharpness off 300 grit diamond stones. Previously I did not think that level of sharpness was possible off that stone.

Your remark about cutting ability being tied to aggression more than pure sharpness rings true. I've experienced the same thing.

You should make a video tutorial of your method i know id love to see it. i hate my plain edge ark because it wont hold an edge but i wonder if your method would make it stay sharp a bit longer.