Diamond stones to microfine vs lapping film

We’ve been waiting for someone to pipe in who is using one of the new 3 micron diamond stones. I think that if you’re getting scratches closer to the 1000 grit scratches, you’re likely not yet broken in. I had some clusters of diamonds on a new 800 grit stone that wouldn’t seem to go away with normal, break-in type of use. I had a piece of plate glass and clamped it in the WEPS vise and had a go at it. After just a few minutes, the clusters had broken off and the stone behaved normally. Be patient. Make sure that your stone is fully broken in before investing in another stone.

You can try a whole bunch of things with the glass platens. Besides film, you could try a little diamond paste or spray on tape. Or stick on a thin strip of hardwood and use paste on it. Diamond grit, spray or paste will work on almost any surface softer than glass. I eventually settled on brass as a platen material for film, but I also tried my 3.5 and 5 micron paste right on the brass and it seemed to work. WE sells a set of handles with aluminum platens and that’s certainly equivalent. Just lap the surfaces to a nice, shiny flat. At $35/pair, four pairs would set you up with all the films you’d want. I use 15, 9, 6, 3, 1.5, 1, 0.5, 0.1 microns. The 15 and 9 microns replace the 1200/1600 ceramics.

I don’t think you’ve appreciatively reduced the life of your stones. The diamond grit particles are attached to the platens with a plating process – nickel, I think. New, there is an abundance of grit piled on the platens. Break-in knocks off those bits which are not lying right on the platen. Once broken-in, a scan with a microscope may well reveal that the particles are almost perfectly distributed; each abutting its neighbors beautifully.

I suppose there is a possibility of over-doing the “forced” break in and rounding off some of the surface “teeth” but I think you’re good unless you can actually see areas where the grit is entirely gone – a good sign that it’s time to replace a set of stones. I have 2 sets of worn out platens which have been replaced for that reason; one pair of 400 and one of 800; the grits I pile the most miles on. Because of this, I also have sets of 600 and 1000 which still have miles left on them if I ever need ’em. In case you’re wondering, yes, the platens can be removed and replaced.