Need advice sharpening a dull razor
First of all, let me tell you what I did to my poor razor: I stropped it on red paste with the spine lifted so that the blade was at an angle of 30 - 40 degrees with the strop. Laugh all you want, I didn't know any better then.
So yesterday I went to a razor sharpening course in the koordenwinkel (which was excellent btw) and I bought a beautiful yellow coticule with a natural blue stone back.
The guy who taught the course had a look at my razor with a lens, and told me what I already suspected. I.e. the edge is gone and I have spend a couple of hours on the stone if I want to restore it.
I spent some timing X'ing away, alternating between the yellow (8K) and the blue (4K). every so often I would do what the teacher told me, which is to test the knife on the edge of a folded post it note. If the edge cuts smoothly you know that the edge is back, and you automatically get rid of the loose barbs and serrations that are hanging on the edge.
When I hold the razor to the light, the light reflects from the edge at the same angle as the light on the spine where it touched the stone. I assumed that this meant the edge was back. Thinking about it right now, I realize that this does not guarantee that both sides of that edge touch each other of course...
I then stropped on red paste (about 20 Xes) and on the leather (10 Xes)
It is still dull. HHT fails, and I can't even shave the hair on my arms.
So here's my question:
what do I need to do? is it simply a matter of spending more time? if so, do I need to back hone in between to prevent overhoning?
How do know when the edge is back?