fast, cheap way to lap chinese 12k
I bought a chinese 12k that had really big saw marks left on it. I had a bunch of loose abrasives left over from a telescope mirror grinding project from a few years ago. I bought a granite floor tile (cost $4) and started with a slurry of 220 SiC grit, then 500 SiC, then 9 u Aluminum Oxide. The slurry cuts *really* fast (much, much faster than wet or dry sandpaper) and the AlOx left it really smooth. I have some 5u lying around but I'm not sure it would be that much of an improvement - the stone is really flat and smooth right now. One thing that is funny is that when you get to the fine abrasive, the stone really sticks to the tile!
I looked online and there is a place called gotgrits.com that sells these abrasives. A 1/4 lb of SiC 500 mesh is about 2 bucks, same of Al Oxide (I think) was about 1.75.
One other thing that seemed to work well - I started on the underside (unpolished side ) of the floor tile whose textured surface helps gather grit (it wears down with the 12k) then finished on the polished top side.
Anyway, just thought I would pass on the idea.
- Ian
a bit more on my experiment
Quote:
Originally Posted by
ruday555
Very good ideas here,thanks for the info.
I forgot to mention that I figured I would do the final smoothing with the slurry stone that came with it (after the 9 u Al Oxide). That worked out really well - both have a kind of glossy look to them. I would love to hear the opinion of some of the honing experts here.
I figure the whole process, from really rough to dead smooth took about 15-20 min. I didn't see any problems with embedded grit at all.
Too soon to tell about its effectiveness as a hone - at first try, it seemed to work well (but I am definitely a newbie at this).
One question to anyone with a geology background: what kind of rock, exactly, is a chinese 12K? It looks like a silicaceous shale (has the shale smell). Just curious (actually, very curious). It is a very interesting rock.