Thread: Lapping a Gokumyo 20000?

I only did one side of mine tho I started out doing both. My stone was warped so it was easier to get it flat on the concave side ie the side that had contact at the 2 ends rather than only in the middle which tends to rock & promote the same shape..
Finishing off with a coticule or nagura gives a nice surface.

As far as any hone that seems warped to one degree or another, I was in the refractory business for 15 years and I can tell you the any ceramic that is fired in a kiln is subject to any temperature variance during the firing process. Therefore, some stones will need extra flattening time as a new stone. Be patient and lap your stones as often and as long as they seem to need it.

Any subsequent lapping will take less time than the initial lapping. I believe that Lynn posted that he has lapped as much as 1/8 inch or more from his Norton 4k stones before they worked well for him. Man made could mean made last week. Natural usually means made 50,00 years ago or more. Have patience with your stones. Give them a second chance to work for you.

I'm just saying.....

Originally Posted by WW243

Stuart from Tools from Japan suggests the diamond plate and discourages you from using paper......my SG needed very little lapping on a 325.

Interesting. Can you expound a little more as the reasoning? I'm soakin' it all up and takin' with a grain of salt, baby!

Originally Posted by Siguy

Interesting. Can you expound a little more as the reasoning? I'm soakin' it all up and takin' with a grain of salt, baby!

The nickel bonding the diamonds to a plate is stronger than the glue holding abrasives to sandpaper so embedding grit is less likely with a DMT etc. Also flatness is more precise as paper does have some give.

With that said it's hard to imagine any particles embedding in such a hard stone as the G20k