my own chartReferencing which uses data from here one can see that the grits of the WEPS diamond plates are not evenly spaced. Notably 80/100 and 600/800 appear rather close while 200/400 appears to be a significant jump. I am curious about the reason for this. It may be that the stones cut and finish differently from what the raw particle size would suggest. I find the micrographs inconclusive due to there being only a single sample for each and no stated control over pressure and stroke. (The 800 plate was used with a different stroke pattern complicating direct comparison to the 600 sample.)
Does the subjective experience with these plates seem to align with what my chart shows, or in contradiction does the step from 200 to 400 actually seem similar to the step from 600 to 800?
These are good questions. I’d like to hold off answering until we complete our new micrographs. We’ve been preparing a host of sample blades to a uniform polish so we can be confident that we’re looking only at the scratches from the grit we’re examining. I also have better stages for all my scopes, so the orientation of the images and the lighting should be uniform. When I originally did those micrographs, I did not control for pressure or age of stone etc… My plan is to shoot images of the samples sharpened with each grit using a new stone and one that is fairly well broken in. I don’t think we’ll get to it until after we’re back from Shot Show, so maybe at the end of the month. I’ll also re-shoot the stones themselves to measure the particle sizes.
I look forward to the full report with growing anticipation.
The new plate micrographs are interesting. The sample area (number of particles) is too small on the lower grits to calculate a distribution but to the unaided eye things seem in the ballpark of what I expected. Most interestingly I note that between 400 and 800 grit we move from an open coat to a closed coat; this should cause the 600 and especially 800 stones to behave as though they are a bit finer, effectively spreading out the 400/600/800 clustering. The 200/400 spacing still looks slightly wider than optimal but another factor I cannot yet guess may counter that. The 80/100 plates also still look a bit close together but perhaps the 100 plate is more tightly graded? Hard to say without a larger sample.
Thanks again for humoring my curiosity, for your time, and for being open to this kind of inquiry.
I will defer to Clay to answer your question, however, I will say that the jump is definitely not too large. The 400 grit stones completely remove the 200 grit stones, once broken in, without too much difficulty. Likewise for the 600-800 jump.
I complete support what Josh writes. The jumps are pretty minor and maybe I should experiment a bit to see whether some stones can even be skipped for the most efficient way of sharpening.