With the ever increasing development of the super abrasion-resistant exotic Uber-Steels in the knife world, conventional sharpening stones are being pushed to their limits, and Ken Schwartz has come to the rescue with his Diamond Sharpening Films.
Almost everyone has a DMT and/or an Atoma diamond plate, but these are super aggressive plates that are great for heavy duty repair and profiling work. For the most part, they tap out at #1,200, or 7 micron, and even although DMT has a 3 micron plate, it isn’t nearly as popular as the lower grits. Traditionally, if you wanted more refinement, switching over to diamond pastes was the answer, but as we’ve been finding, pastes generally don’t have nearly as much “punch” as the plates. This is due to the overall lack of abrasive concentration, and the fact that while the size of the abrasives are consistent, the depth of scratches from the plates are much deeper than those from the pastes.
So the problem lies in finding an all-diamond progression, on a consistent medium, AND with a huge range of grits. Ken Schwartz has found that solution with his diamond films on Float Glass, which range from a whopping 165 micron (100 grit) to 0.1 micron (150,000 grit!). Not only that, it’s currently available in several sizes: 1″ x 6″ for the Edge Pro, 2″ x 6″, and a “full size” 3″ x 8″. They can be custom ordered to size as well.
I have a couple of Uber-steel knives, including a Rex-121 Mule from Farid, but we all know diamonds can sharpen anything, including ceramic knives, so I opted for what would make the best microscope pictures – a straight razor. In this case it’s a vintage Torrey Wedge. Besides, you don’t need super hard steel in order to opt for diamond sharpening. :) The pictures were all taken with a Veho-400x USB scope and actual size of the pictures is .75 mm tall by 1 mm wide.
Since the Torrey was already in good shaving condition, I did not need to step back to the 165 micron diamond sharpening film, and opted instead to begin with the 45 micron (320 grit) to re-establish the bevel. I used the 1″ x 6″ Edge Pro size since it makes dealing with warps and other razor-related issues. In fact, I pretty much exclusively use the 1×6 size for honing razors.
From the 45 micron film, we can see an edge comparable to the #320 Shapton Pro – a little serrated, but quite consistent.
From here, I progressed to the 30 micron (500 grit) film.
30 micron (500 grit) is still quite coarse in terms of razors, but the edge of the edge is already starting to clean up.
Next is the 20 micron (800 grit) film.
Again, 20 micron (800 grit) is still quite coarse (and for razors is probably the coarsest grit needed, if at all), but things are looking quite nice. This would be acceptable for a working edge on a knife.
Then onto the 9 micron (1,500 grit) film.
I’m completely impressed with the 9 micron film. The edge is looking clean, and the scratches are much more consistent with water stones than diamond plates.
6 micron (3K grit) is next.
As we can see from the difference in the reflective lighting on the bevel, we have entered into the “critical leap” area of the films. There is definite polishing happening at this stage, so we can say the critical leap is between the 9 micron and 6 micron. However, I personally feel it’s between the 6 micron and 3 micron (6K), as we will see below.
The reason I would rather call the 6 to 3 micron the critical leap is because of the sheer “flatness” of the bevel off the 3 micron. Either way, at this point we are certainly sharp, and headed toward the land of shaving!
The 1 micron (15K) film is next.
Although the edge of the edge is certainly consistent and able to shave, we begin to run into some razor-related issues. This picture is reminiscent of the 16K Shapton Glass post I did a while back, where the Swedish steel was quite brittle, and began to chip out as the steel got thinned beyond it’s capability. That has much more to do with the characteristics of the steel, and NOT the quality of the diamond films.
Here we can see the 0.5 micron (30K grit) film is pushing the limits of the Torrey, however, the bevel itself is quite clean.
Since I was also testing a progression of Ken Schwartz’s diamond sharpening films for a razor customer, I switched here to finish the razor on Ken Schwartz’s 0.125 micron CBN on balsa instead of going to the 0.1 diamond film, as was requested.
Obviously, the diamond films work, and they deliver in full from coarse to ultra fine grits. You also don’t need super hard steels in order to use or benefit from the diamond films, and since we are dealing with diamond abrasives, you get much longer cutting action out of them than conventional sand paper. Ken Schwartz has hit a home run in my book!
By the way, the shave was wonderful