Quote Originally Posted by Chrisl View Post
Holy smoke! What hone were you using to lap the 12K for 30 hours if I might ask? If it was a DMT, that concerns me that it took that long (not questioning your lapping ability in any way, I say it concerns me because I'm wondering if maybe you're DMT is more broken in than mine and maybe I'll have to prepare to work mine that hard as time goes along). I got a 12K from Woodcraft just last week and lapped it on the DMT 325 grit. It took me an hour (I did lap only one surface and added beveled edges), about as long as it took for me to lap my Belgium Blue. Sure an hour isn't a long time in comparison to what you guys are describing, but it's alot longer than lapping a Norton!
I was using a DMT 325 that previously had lapped a Swaty, 2 carborundums, a norton 1000, a norton 4000, and a norton 8000. My 12K was convex--the center faces were highest in the center. That means as I lapped, the center became smooth and the edges were untouched. As lapping proceeded, the smooth center got larger and I was therefore lapping a progressively larger area and the progression out to the edges became slower. That is why I stopped when all but the last 1/2 inch of each corner was polished--the greater the polished area, the slower the lapping was going. Because I like to hone on narrow stones, on both the 12K and all three nortons were honed on a wide side and a narrow side.