I think I've made it pretty clear how much I like my C12k - it's inexpensive, it puts a great finish on my blades, and once lapped it's good for quite some time. But there is one disadvantage that many people point out; it is a slooooow stone. This slowness never really bothered me, but I've got a lot of blades that I'm working on these days, and I wanted to see if I could speed things up a bit.
A couple weeks ago, I was experimenting with my Swaty by going straight from the 1k to the long Swaty to see how that would work. I found that just doing normal laps was pretty slow going, and, inspired by JoeD, I decided to try some circles. This sped up the process greatly, and now circles on my Swaty, followed by normal passes, are part of my honing routine. So I was thinking to myself, if circles work on the Swaty why wouldn't the work on the C12k.
This isn't really anything all that crazy, but I've never seen anyone talk about doing circles on a finisher. I'm not sure if this is because people want the scratch pattern or if they don't need to spend that much time on their finishers or what, but since the C12k is so slow, it seemed like a good idea. I ran the idea by JoeD one afternoon when he stopped by my place, and he said it sounded good to him. I was glad to hear that, because JoeD is way, way, way more knoweldgable about metals than I am.
So today was my first shave with blades that I circled on the C12k. To give fill disclosure, here's my honing process. I set the bevels on my King 1k. This involved circles on one of the blades and just normal passes on the other two. I then went to my long Swaty, starting with about 20 seconds of circles on each side, followed by about 30 normal passes. I then went to the C12k for about 25 seconds of circles on each side and then about 40 passes. The blades were an American Knife Co (full hollow), a Herbertz Solingen (just about a full hollow, maybe a touch thicker), and a W&B (about a quarter hollow). I'm not sure if the American is actually American Steel (looks like a Sheffield blade but says Plymouth Hollow), but I figured it was a good variety of steels. I am pleased to say that all of the blades were extremely smooth shavers.
Now I'm not actually sure if I saved myself any time, because I've never timed myself on a C12k. However, having the variation of circles and normal laps on the C12k made it feel quicker. I also don't have the patience to do 100 laps on my C12k, so I usually call it quits around 60. This has also showed me that doing circles on a finisher (or at least on this finisher) can indeed work quite well. Furthermore, the scratch patterns that are left on the blades are not the regular parallel (////) lines that my other blades have, so it seems that pattern is not all-important.
While this is by no means a full experiment, I think my results thus far are rather informative, and I'm going to continue with circles on my C12k. If anyone else has tried or is inspired to, please share your results. (I'm pretty sure JoeD said he tried it, but I'll let him speak for himself, if he chooses to).