So I’ve recently changed my thinking that the Shapton Professional Stones are the best in any sharpening situation (excepting Lie-Nielsen D-2 Cold Hardened plane blades, for which the glass series is specifically designed). The Shapton Glass Stones, seem to be better suited for straight razors (with some exceptions, though…)
I had my theories for about this for 3 months of so, but only know has it been proven which might be better suited for straight razors. My thinking was this: The professional stones keep their shape longer, therefore the bevel on the straight razor would be “straighter”, while the softer glass stones would produce a slightly rounded or convexed bevel.
It looks like the glass stone theory was correct, but there’s more to it now. I think the consistency of the glass stones’ softness through the series is what allows each consecutive stone to conform to the slight roundness of the bevel in fewer strokes than it would take the professional series stones to either abrade the edge flat and/or conform to the bevel.
Think of it this way, with the Glass series, the stones conform to the edge (making sharpening faster), while the professional series makes the edge conform to the stone (making it take longer). That is why some people have reported the higher grit pro stones requiring more than the usual amount of strokes. This makes sense because little or no pressure is used on the razor when sharpening, so wearing down a pro stone will take some doing – especially at the higher grits.
So armed with this new information, which series is now better for straight razors?
Think before you answer…… : )