6K Shapton® glass stone was one of the stones that I have received from Takeshi, they guy who owns aframestokyo.com website, which I might add is a premium source for a very wide variety of Japanese kitchen knives, synthetic and natural whetstones, etc. Anyway, I've received 3 stones and a stone holder, and I happily proceeded with prolonged testing. For the record, I was familiar with Shapton® Glass Stone™-s long before I got them. There's always plenty of discussion regarding them on knife related forums and I've owned Shapton® Glass Stone™ 220 Grit for a while before I got the new ones from Takeshi in 2010.
General
- Shapton® 6000 grit glass stone is the same size as the rest of the glass stones, measures 210mm(8.25")x70mm(2.75"). The height is about 10mm, where the stone itself is 5mm, and the rest is the glass base. Because the base is a glass, you need an appropriate holder for it. Ostensibly, you need a holder for any sharpening stone which has no base, otherwise it will either slide as is the case with Shaptons, or a stone with dual surface will do numbers on the table. As for the 6K stone itself, well it is a high grit stone which is supposed to be used for mirror polished, very refined edged. Some of the sources consider that a razor stone, but most agree 10K and above would be a final stone for the razors. To be complete, there is a wide array of Natural Japanese Whetstones which have the range of 6k-10k, due to specific nature of those stones, in other words slurry breakdown during sharpening. Shapton is a synthetic stone, and as I have mentioned in other reviews it's slurry won't break down to finer grit during sharpening, at least nothing I could notice on wide array of knives I've sharpened with all the Shapton® Glass Stone™ I have.As usual, higher grit stones are harder, which means they wear at a lower rate to begin with, and when used correctly, they don't experience huge pressures either. Because, by the time you get to 5K and above, the edge is already way beyond shaving sharp, mirror polished, and all that, so excessive pressure will only damage the delicate edge. Therefore, those high grit stones tend to last longer, but you need to keep them really flat to benefit the most. One thing is, those high grit stones will be used more often for touchups if you used them on during first sharpening. In other words, if I finish sharpening with 10K stone, next few touchups will be with 10K stone, unless I manage to damage the edge somehow, or dull it real bad in one session.
Performance
- Shaptons do have pretty good reputation, most of the complaints are about their durability and for some people they seem too harsh compared to other types of whetstones of the same grit. I already had Naniwa Chosera 5000 Grit Synthetic Whetstone, and because of that I wouldn't be shopping for Shapton 6K stone, as usual I go with 2x grit for each next step, which means in my typical multi stone sharpening sequence after 5K Naniwa I go straight to Naniwa Chosera 10000x Super Finishing Synthetic Whetstone, but 6K can be used instead of the 5K stone, which is what I did, whenever I've used it. Judging by tactile feedback, I couldn't tell which stone was which, i.e. blindfolded test 5K Naniwa vs. 6K Shapton :) Although, when I was looking and them and testing the surface Shapton did feel smoother. In other words, humans aren't really all that precise :)As for the sharpening process itself, 6K Shapton was quite good. Sprinkle some water, create slurry using Nagura and start grinding. Exactly the same procedure I'd use for Naniwa 5K. On its own Shapton 6K produces very good mirror polish on the edge. On its own Shapton 6K produces very good results. It can be used as a final stone before moving on to the micro abrasives or strops, or it can be a stone preceding higher grit stones. 6K edge is a very fine edge for a knife. I do prefer much higher edge finishes, but for most of the uses 6K is plenty enough. Coming from the 2k-4K stones, the mirror polished edge forms quite fast. Depending on the alloy wear resistance and hardness it can be anywhere form 5 mins to 10-15 mins. Obviously highly wear resistant alloys like CPM 10V, CPM S125V, CPM S110V, Bohler-Uddeholm M390 take more time, simpler, low alloy steels are easier, hardness isn't really critical factor there, I mean polishing. Getting 6k worth of the edge is a matter of experience and precision. Keep in mind, focus is the edge, mirror finish is secondary :)
Comparing with Naniwa Chosera 5K stone, I'd pick Naniwa. It's bigger, thicker and combined with Nagura stone produces smoother mirror finish over the time. That is my impression after several years of use. Plus, Naniwa lasts longer and I do sharpen a lot, compared to average person that is. Shapton's advantage being fast because of no soak time is rather moot point, unless you are doing an express touch up and need to jump on 6K stone from the get go. Otherwise, by the time you need 6K stone, it'd have plenty of time to soak in the water, thus no real savings there.
Conclusions
- If you are looking for a compact, light stone for refined edge 6K Shapton might do it for you. In fact I gave the stone as a gift to a visiting friend, and he seems to be very happy with it. it will also work well as a fast touchup stone for the edges up to 6K, or a bit above it too. Depending on how much you are sharpening, you may or may not have to worry about the stone degradation. 6K stone is hard, and it won't wear down easily.Related reading:
Last updated - 05/19/19