Re: Polished edge

[Phil Pasteur]

Well..
Here I go again. We had a long topic where we discussed what a mirro bevel really is. It seems that many people call many stages of reflectivity a mirror. If sharpening myself I consider a mirror to be a mirror… an edge just as reflective as my bathroom mirror, and with less than 5% coverage with visible scratches.

You simply can’t easily get that with the progression that you mention. Actually, I don’t think it is possible at all without spending hours on the strops. Recently I tried on some D2, AUS 8A and S30V. I used the diamonds through 1000, then the 1200/1600 ceramics, then coarse and fine microfine ceramics, then 6/3 and 1/0.5 micron paste/spray respectively. What can I say, the bevel was somewhat reflective, but with lots of visible fine scratches. For the application the knives will be used for… it was fine.. and they were very sharp.

The ceramics leave what I would call a semi reflective (shiny, but no mirror) edge. Even after 100 strokes each side with all four ceramic grits, there were lots of visible scratches. Now in this way they are more similar to the Shapton stones. They just don’t supply much in the way of polishing ability at all. You can make the bevel brighter with the strops, but you would need hours of stropping time to get rid of the visible scratches. If you want a real mirror (in my definition) you need some stones that polish as well as abrade. Even the 1000 grit Chosera stones will give you a much more mirror like bevel than the sub-micron ceramics. I have 5K and 15K Shaptons that I will not use when trying for a perfect mirror, because, although very precise, like the Ceramics, they leave… perfectly aligned and very precise Scratches! A great edge for cutting things…but scratchy…
BTW I test by holding a bright flashlight almost parallel to the edge. By cahnging the angle it is easy to see both the amount of reflectivity and the damn scratches. It really shows scratches that you may not see in normal light and looking at the bevel perpindicularly.

I can tell you that getting to my definition of a mirror edge is time consuming. I use 13 different grits of stones and eight different grits on strops from 3K up I am doing 150 strokes…or more per side… 3 to 4 hours… and often I am not really satisfied with the results.. I can still see some scratches (AAARG). However, when I have compared these edges with some of the stuff my local sharpening buddies call a mirror edge… they quite amazed at the difference. There is at least an order of magnitude more reflectivity and scratch removal.

So, it is all about what you want. This whole perfect mirror scratch free thing is all about OCD and just saying…I can do it. It sure does not make the knife orders of magnitude sharper… BUT, it is an eye catcher and has gotten me quite a few sharpening jobs 🙂

Phil