Diamond plate rougher than oil stone?

[Michael Bulatowicz]

Diamond plates often have some diamonds that are large and stick up considerably higher than the other diamonds.

Here's a picture of a DMT extra-fine plate, from this post on the Science of Sharp blog. There's a huge diamond in the middle of all the other small ones.

Attachment 445209

According to that blog post, some of the large diamonds will fall out after a break-in period, but some will remain. Eventually these diamonds will wear down or fall out, but it can take a long time.

I've had DMT plates and currently have a Trend diamond plate that initially left deep scratches but then got better over time. My understanding is that Atomas have more consistent sizing, although I've never actually used one before.

This image appears entirely consistent with my experience of the DMT Extra Fine. Both my 6x2 inch and my 8x3 inch leave a number of deep scratches that are difficult and time consuming to remove with finer honing media. Particularly troublesome is any occurrence in which one of these larger diamonds gets dislodged, skates along, then catches at some other point in the surface and starts leaving even deeper scratches. I no longer use the extra fine DMT for any of my woodworking tools for this reason.

[John K Jordan]

This image appears entirely consistent with my experience of the DMT Extra Fine. Both my 6x2 inch and my 8x3 inch leave a number of deep scratches that are difficult and time consuming to remove with finer honing media. Particularly troublesome is any occurrence in which one of these larger diamonds gets dislodged, skates along, then catches at some other point in the surface and starts leaving even deeper scratches. I no longer use the extra fine DMT for any of my woodworking tools for this reason.

I've tried a variety of diamond hones and for small hones I like the EZE-LAP better than the DMT - I think it is better made and lasts longer. Some years ago I bought a lifetime supply directly from the EXE-LAP at a much reduced price. I use the extra fine more than any of the others.

hones.gif

My time in a metallography lab preparing samples for microscopy taught me one thing - the value of consistent cleanliness. I constantly rinsed grind plates, polishing disks, and the parts themselves in running water. Parts with voids went into an ultrasonic cleaner between abrasives.

JKJ

[John C Cox]

I've also seen that some of the newer diamond plates were "scratchy"... This can be a handy thing with knives, as it helps "bite" in a cut.... But not so much on chisels and planes... Like everything else, one man's trash is another's treasure... and a scratchy stone can take a slicing knife to a really cool place...

[Jim Koepke]

I've also seen that some of the newer diamond plates were "scratchy"... This can be a handy thing with knives, as it helps "bite" in a cut.... But not so much on chisels and planes... Like everything else, one man's trash is another's treasure... and a scratchy stone can take a slicing knife to a really cool place...

For me a very sharp blade without the "scratchy" is better for slicing tomatoes or rope. A knife with a "scratchy" edge tends to snag for me.

As always… YMMV!!!.png

jtk