No questions asked, they are the most used sharpening tool out of all the sharpeners I have. I've been using them for last 6-7 years non stop. Abrasive film is just another name for specific type of sandpaper. They work exceptionally well on any steel, I have tried them with. So far I've seen and used three different types of abrasives, Silicon Carbide(SiC), Chromium Oxide(CrO) and Aluminum Oxide(Al2O3). Generally, the films, regardless of the abrasive material used in them, come in two types, adhesive and standard film baked. However, with smooth enough surface, e.g. glass, polished metal, marble, granite, etc, all you need is a few drops of water to make it adhesive ;) I've never bought adhesive film, but never felt the need for it either.
Electrostatic Effect- Another, interesting aspect, worth mentioning here, is the electrostatic effect. The electrostatic effect causes those films to stick to the leather pads and some other surfaces. Which, is definitely attributed to the baking of the abrasive. One way or another, it does do the trick, and after a few passes with the knife on the film, it sticks to the leather. No water needed. Of course that works on leather, and some other types of surface, but not on everything.
Convex Edges- May be you've heard of sandpaper/mousepad trick, or if you haven't that's pretty simple, you put sandpaper or the abrasive film on the mousepad, or a leather pad(like I do) and sharpen on it. Perfect way to learn sharpening convex edges. generally, the softer the surface, the greater convex the edge will have. Harder surfaces, with lesser give will result in more straight, or V shaped edges. It's a trail and error path, and you'll have to figure out your perfect combo, which may vary from knife to knife, or from edge to edge.
V edges- The same sandpaper/abrasive films work very well for the V type edges. Just replace soft base with hard one, preferably glass, due to its almost perfect smoothness of the surface. Few drops of water and the film is stuck to the glass, and you're ready to grind your perfect V edge with it.
I use several films with various grits as usual, on a leather pad for convex edges or a glass base for V type edges. Depending on sharpening work I use 15, 5µm SiC, 2µm CrO and 0.3µm Al2O3 films.
15µm Silicon Carbide(SiC)- This abrasive is an equivalent of 1200 Grit US, or 1000 grit in Japanese Whetstone grit classification. Works very well as a starter sharpener after initial bevels are cut. For rough use or utility knives requiring coarse edge such as: Phil Wilson CPM-10V Knife or his CPM S125V knife, it can be a final finish. Cuts fast, and wears down relatively slow. One sheet is good enough for 4-5 knives, depending on the amount of work. I've used it on all types of steel, including ultra-hard, extremely wear resistant alloys such as CPM-10V, CPM S125V, whatever alloy in Aritsugu A-Type Gyuto, or 65HRC+ Aritsugu Yanagiba. SiC can handle it all. Not at the same speed, but works well.
5µm Silicon Carbide(SiC)- This abrasive is an equivalent of 4500 Grit US, or 3000 grit in Japanese Whetstone grit classification. It's the same SiC described above, so works the same, but lasts longer, due to smaller particle size. In my experience 1 sheet was enough for 7-8, or sometimes even 10 knives. Puts very nice cutting edge on the knife. For combat, and bunch of utility knives that's where one would stop, unless ultimate sharpness is desired. Arguably, it's a big jump from 15mic to 5 mic, but I've been doing that regularly, no problems so far. SiC cuts so fast that I don't feel I am done unnecessarily long work with it. If you still prefer, to have intermediate step between 15µm and 5µm, then there is 9µm Al2O3 film. I've used 5µm film on pretty much on all of my knives, including those listed above. Results in a very sharp, polished edge.
2µm Chromium Oxide(CrO)- This abrasive is an equivalent of 10000 Grit US, or 8000 grit in Japanese Whetstone grit classification. Cuts quite fast. Although, it is hard to compare the cutting speed of different grit abrasives, I still feel that it works at little bit less speed compared to SiC. However, this might be just my impression. Can't really extrapolate the speed. 2µm is very fine grain, because of that CrO films last really long. I've used the same film sometimes for 15knives before replacing it. Works well as serious touchup sharpener. Final result is mirror polished, very sharp edge.
0.3µm Aluminum Oxide(Al2O3)- This abrasive is an equivalent of 80000 Grit US, no direct equivalent in Japanese Whetstone grit classification. Cutting speed is pretty good. Although, at those levels as usual the work is short. You go to that abrasive for final step. It used to be my final finish before I have discovered 0.25µm Diamond Spray. Results in a highly polished, very refined edge. BTW, not all the alloys can take the edge this fine. So, watch out :) Nice one for touchups once in a week or two. Depends on the knife, obviously. Lasts very long time. 30-40 knives with it are no biggie. Also, on the unrelated theme, worked very well for CPU and CPU block lapping.
Last updated - 09/01/11