I have heard great things about diamond stones but I just put money into a nice set of arkansa stones and was just hoping to not have to buy another sharpening system.
Might be a little marginal, with Arkansas stones. N690 is roughly similar in composition to 440C, with about ~ 1% carbon and ~ 17% chromium. Other similarities to VG-10 as well, with molybdenum and cobalt in the alloy. Heavier grinding may be difficult (VERY slow) on Arkansas stones, although they might work OK at the finer end for finishing up.
I'd suggest a simple two-sided Coarse/Fine SiC or AlOx oilstone for the heavier work, like reprofiling, edge repair, etc. After setting the edge and doing most of the burr cleanup with the fine side of that stone, the Arkansas stones might contribute some more refinement (finer finish & polish) at the high end. With that being said, the same carbide content that makes grinding slow at the start, will also (at least somewhat) impede better results at the refining end. Man-made (synthetic) AlOx or SiC stones will always cut such steels more effectively, and would be my preference for a 440C/VG-10-class steel. Decent stones of this type will run $15-$25 or so, in an 8" bench-sized version (Norton 'Crystolon' for SiC, and Norton 'India' for AlOx, for example). Not too much extra money spent, for the better results afforded by them.
Consider that many 'tri-stone' sharpening setups featuring Arkansas stones usually include a relatively coarse SiC or AlOx oil stone as the
first stage; it's there for good reason.
David
