Precision flatness

[EdgePal]

Whiteboard ink are, dry, 2/100 mm thick.
Permanent ink are, dry, 1/100 mm thick.

This knowledge can be used in this way;

I am working with a very abused straigt chissel. I like yo get the total edge as flat as I can.
I use a sharpening tool, the angle are locked and the chissel are locked om the grinding table. Nothing can move more then the sharpener.

Pic 1
I use the whiteboard ink and make a X on the edge.

I use the sharpener and move it forward and back 2 times. The result can you see in pic 2.

Then I do it once more but now with petmanent ink, you se the X in pic 3.

I move the sharpener in the same way as I did the first timre on the edge, and the result can you see in pic 4.

Now have I located the part of the edge that is 1/100 part of 1 mm higher then the other parts and can concentrate on to grind that part flat.

I use, in this.pics a 60 micron DMT diasharp sharpener that I have cut in 2 parts, one is 30mm wide, the other are 20 mm wide. For me very useful sizes.

I use the sharpener with very low pressure.

Pic 1. https://i.ibb.co/6rJtg96/All-focus.jpg
Pic2. https://i.ibb.co/prwzjTR/All-focus.jpg
Pic 3. https://i.ibb.co/Pzkr0Yz/All-focus.jpgt
Pic 4. https://i.ibb.co/sW21j3n/All-focus.jpgt

 

[Working Edge]

If I'm understanding you correctly, you are using the two different "thicknesses" of ink to locate and grind a secondary bevel, like a large micro-bevel?
Very clever...!
Mark