Re: Further on Convex Edges
I tried all three methods for obtaining a convex mentioned in this thread (from high angle to low angle, from low angle to high angle, first low angle then high angle then in between). I made photographs of the knives using a microscope for each method to be able to see the differences between the methods. Guess what… I cannot see any difference, neither with the naked eye, nor with a microscope 😀 .
In fact, it was very difficult to distinguish the four different edge bevels I created on each knife before stropping, let alone to compare them.
So here’s just one set of pictures, of a 12C27 pocket knife at each stage in the sharpening process. I made a convex edge from 18 to 21 degrees. All pictures were taken with a Veho 400x magnification microscope.
First, the 100 grit stone at 18 degrees, in order to obtain a burr. This took the longest:
You may wonder how I held the knife in all of the pictures. In fact it is in the WEPS vice all the time. However, the microscope is round and I forgot where “up” is 🙂 . Then the 200 grit stone:
400 grit:
600 grit. Looking much better already:
800 grit:
1000 grit. The edge is starting to look civilized:
1200 grit
1600 grit. The final lowest angle bevel at 18 degrees.
Then I added a second bevel at 21 degrees. At first I used a 1600 grit stone. However, when I saw no second bevel appear, I switched to 1200 grit before going to 1600 grit again. I probably shouldn’t have done this, since I removed slightly too much material:
It is perhaps easier to see at a 20x magnification:
Then a third bevel at 20 degrees. I did about 50 light push movements per side of the blade with the 1600 grit stone:
Finally a fourth bevel at 19 degrees. It was hard to make a photograph actually showing all four bevels, but with some effort you can see them:
Then on to stropping. I first did about 50 passes per side of the blade at 19 degrees using 5 micron paste on a leather strop. Then I did 50 again at 20 degrees using 3.5 micron paste. The final result:
And I got very similar results with the two other methods.
‘there are many paths to enlightenment, so choose your own path and tread it boldly!’
I think either approach will work – from the lower angle up , or higher angle down.
Indeed 😀 . And the proof of the pudding is in the eating.
Molecule Polishing: my blog about sharpening with the Wicked Edge