Thanks for the answer. Is there a reason for not using it again? I kind of like the idea with a big round stone, when sharpening longer knives it could be useful.
OT: I spent the new years morning sharpening one of my brothers knives. A Henckles five star I gave him two years ago, I kind of miss the knife; One of the best western handles I've ever encounterd.
The knife was absurdly blunt when iit was handed to me so I started with a DMT and continoued as follows:
Naniwa #400
Shapton #1000
Naniwa ss #2000
Naniwa ss #5000
...and finally a strop loaded with chromium oxide.
Kind of a overkill, but I really wanted to give him a sharp and convex edge for the new year.
The steel were really easy to sharpen but the bolster was a PITA.