I don't have access to a microscope to give a real side-by-side comparison, but I can tell you that after the 1000 grit diamonds, the surface is still scratched and toothy, whereas after the 1000 grit 3M sandpaper, it starts to take on a mirror finish and lose its teeth. I don't know WHY this is, just that it happens.

To be honest though, unless I'm feeling particularly OCD on a given day, I skip the 1000 and 1500 sandpapers, and go from 1k diamond to 2k sandpaper. It doesn't get rid of every scratch, and it takes awhile longer, but it's such a pain cutting out little rectangles of sandpaper and taping them to the same stone three times for each knife.

I think the answer is the hardness of the diamonds vs the abrasives on the sandpaper along with the friability of the abrasives on the sandpaper. The diamonds don't give at all and cut deeper grooves. They also don't break down easily (though they do break down somewhat) and most likely the abrasives on your sandpaper do break down quite quickly into smaller particles.

MathewWhaley wrote:

Here is a link to a great chart on grits of different materials. It includes the WEPS diamonds and the FEPA P abrasives.

www.bladeforums.com/forums/showthread.ph...ied-Grit-Chart/page3



Notice that the P1000 paper is 18 microns.
P2500 is 8.5 microns.
WEPS 1000 grit diamonds are listed at 7 microns.

I used to use sandpaper before I got stones to cover my progressions. I too noticed that the p2500 and eveb the p1000 paper would give me a much better polish and less tooth than the diamonds. I also noticed that the paper wore down much faster than I liked. I tend to think that Clay has to be right on this. The abrasive on the paper is breaking down to finer sizes. It is another example of how it is hard to choose a sharpening material simply based on the abrasive size. In fact I would go down to 0.3 micron 3M lapping paper taped to my 1000 diamonds. I never could get the level of polish nor edge refinement doing that as what I can do with the CHosera 10K which has abrasives sized at about 1.7 microns.


mark76 wrote: