In a video Lynn Abrams mention that new Norton (220/1000 or 4000/8000) need to be prepped
with a flattening stone before first because the surface is coarser than expected. Can anyone confirm.
I bought a 4000/8000 several years ago for my razor and added a 220/1000 for Japanese knives.
One ne razor (maintained with strop and paste for years) need honing now. How long should I use
the flattening stone.

Sylvain