Ooh! Lots of questions…
I use diamond film a lot and I’m having almost no problems with it. Recently I made the mistake of trying to lap my ceramic stones on a 1200 grit EZE-Lap plate. This removed the surface finish, which was the key to the 1.4/0.6 micron equivalent, so I’ve put both pairs of ceramics on the shelf for now.
I have a bunch of home-made glass blocks, so I keep all the different diamond and AlO films at hand. My polish progression goes from 1000 grit diamond to 15 micron film (the equivalent of 1200 grit) to 9 micron (1800), to 6 micron (3000) to 3 micron (8000), to 1.5, to 1.0 to 0.5, and finally to 0.1 micron. Four pairs. All are diamond except for the 9 micron, which is Aluminum oxide.
For lesser edges, I may stop at 1000 grit, or maybe the 15 and 9 micron. I haven’t yet tried the 200-grit micro-bevel
I think there’s some learning curve required to keep your film from being sliced. First, it is really important to get your film applied perfectly. Any dust contamination or bubble will raise a bump in the film which for sure will start a slice. I carefully wipe the glass down with an alcohol wipe, watching for any contamination. Then I take my film strips and hold the ends with thumb and index fingers of both hands and stretch them out tight as I lay them down. Don’t worry about contaminating the ends - you won’t use the ends anyway. I think stretching is important, because it helps attach the film more tightly. A tight stretch means a harder film surface. A harder film surface means more resistance to cutting. I then wipe (squeegy) the surface with a dowel, pen or screwdriver, whatever, to squeeze out any bubbles and to press every last bit of backing adhesive down onto the platen. If you see a bubble or bump forming and it’s still possible, peel the strip off, clear the problem and reapply the strip.
I often use scrubbing strokes, but only on straight sections of the edge. A deep belly or concave edge will dig into the soft film, producing a beautiful cut, much like you did with your leather strops. Come on. Everybody does it. Like your strops, unless the cut is catastrophic, you can probably still use it. A little bump in your stroke ain’t gonna do much.
I don’t use a liquid media on my films, so they build up dirt and swarf after a while. I find that they clean up very nicely with the Superaser Wicked Edge sells. I’ve looked closely with my 180X USB microscope and if I don’t see areas of the grit which have been clearly wiped clean from the substrate, I assume the grit is still attached. I haven’t paid attention to the actual life of the film, but when used properly (say, maybe 20 strokes per grit) I think that 15 to 20 knives is possible, depending on the length of the blades. Maybe more. I don’t do a lot of blades longer than 3-4 inches.
I recently changed out all of my films, just to start with a clean slate again and I was amazed at how effective the films were. It was clear to me that I had some serious contamination problems. Without the scratches from contamination, the number of strokes required per film grit was greatly reduced. I knew that I had been a notch worse than careless. It wuz a lesson learnt.
To explain the microscope thing further - if you look at the surface of the film closely, you’ll see a matrix of dots, distributed very uniformly over the film. When the film reaches the end of its life, you’ll see areas which have no dots. I assume that them there dots is diamonds, and that diamonds don’t wear out; they wear off. So if the dots are still there, I assume the diamonds are still there. Pretty simplistic, but until somebody smarter tells me different, that’s my story and I’m sticking to it.
Another late night symposium I’ll probably regret.
Tom
, their prices are cheaper for genuine 3m lapping film products.