Ever Since Jens won the shaving competition by shaving his head with a chisel, everyone pretty much accepted the fact that whatever came next would take second place to his pure originality and genius/madness.
Until now. (video is below)
I stumbled on the ceramic knife as a razor quite by accident. As an experiment, I was sharpening a Kyocera ceramic paring knife as a reed knife when I noticed that the edge was getting sharp enough to actually cut some hair after using Ken Schwartz’s diamond paper at 6 microns. I immediately went to the store and bought another Kyocera Ceramic Knife – but the smallest they had was the utility knife, which was a little longer than the paring knife. No problem for me, though, since I’ve shaved with 10″ knives and big cleavers 😀
The factory edge off the ceramic knife is actually quite impressive – it’s sharper than a lot of other knives right out of the box, but it does require a sawing motion to be most effective. I’d rate the factory edge at about 2K, or 8 micron. The edge angles were a little steeper than I wanted since ceramics don’t have much give like steel knives, and they will chip out due to their ultra-hardness if the angles are too low. But for a straight razor knife, the rigidness of the ceramic blade could be combined with lower angles since the edge wouldn’t fold or roll like thin steel at lower angles.
Ken’s diamond papers come in in several sizes and span a huge range of grits (from 165 micron to 0.1 micron, or approx. 100 grit to 150,000 grit). For this project, I used his 3″x8″ diamond films on glass. I started with the 74 micron (~200 grit) diamond paper to establish the lower bevel angles. Since this was being done freehand, I would guess about 10-15 degrees per side is where I was aiming. As hard as ceramics knives are, I was quite amazed just how easy it was for the diamond films to abrade the knife. It was just like using a conventional sharpening stone on a piece of steel – I was using both forward and backward strokes (as opposed to single sided strokes) – and many of the same characteristics of sharpening steel still came into play, even though the most obvious feature that was left out was the lack of burr formation. The 75 micron was almost a little too aggressive, but it made quick work of the profiling. Then I went through the grits step by step – 45 micron, 30 micron, 20 micron, and 15 micron (320 grit, 500 grit, 800 grit, and 1K, respectively). It was a bit overkill since the diamonds really did perform, but I was still on a learning curve, so it was safer not to skip. I also did enough strokes to make VERY sure I had reached the edge of the edge since there were no real indicators of sharpness. I monitored the sharpness under my microscope (no pictures on this one, I was in too much a rush!)
It wasn’t until I reached the 9-micron and 6-micron films (approximately 1,500 and 3,000 grit) that the edge finally began to feel noticeably sharp. At that point, it would cut arm hair, although it still required a little pressure. That was enough to confirm the progression was working exactly as expected, and I knew the edge was heading in the right direction.
After moving to the 3-micron film (approximately 6,000 grit), the improvement became much more obvious. The knife easily push-cut paper, and arm hair was removed with much less effort. This was the same level where I had previously stopped sharpening one of my reed knives, but for a straight razor I wanted to continue refining the edge.
The next step was the 1-micron film (approximately 15,000 grit), and it delivered exactly what I was hoping for. The razor became fully shave-ready, and under the microscope the bevel looked very similar to a finely sharpened steel razor, with an even cleaner scratch pattern. While the edge was extremely sharp, I still felt it required just a little more refinement to reduce the effort needed to catch and cut individual hairs.
That changed when I moved to the 0.5-micron film (approximately 30,000 grit). The difference was immediate. The edge felt much more responsive, and the razor easily treetopped arm hair before touching the skin. At this stage, I recommend switching entirely to edge-trailing strokes no later than the 1-micron film. Any accidental change in angle or even a small piece of debris on the abrasive can damage the sharpening film.
Although I was already confident that the razor would provide a comfortable shave after the 0.5-micron finish, I wanted to take the experiment one step further. I finished the edge using Ken Schwartz’s 0.025-micron Poly Diamond Spray applied to Nanocloth. I had been looking for an opportunity to evaluate this finishing combination, and this project proved to be the perfect test.
The final stropping step added another level of refinement. The edge felt smoother during cutting, and the blade moved across the skin with noticeably less resistance. That extra level of glide was exactly what I had hoped to achieve before the shave test.
As for the shave itself… the challenge had already been set. Jens, the Viking from Sweden, had raised the bar, so it was time to see how this edge would compare. I think I managed to meet the challenge at least for now.
Useful links – Big Fish Knife
Taiwan Tuna Knife, Big tuna Knife – Master Kuo FN Big 1600
Taiwan Tuna Fish Cutting Knife – Big Tuna Knife Master Kuo (FN Big 1400)
Hehehe! Very funny video! 🙂