Thread: Yet another lapping post

Ok guys, I realize there are a lot of post about this already, and I have been through them all. But I am still a little confused. The norton is coming in either today or tomorrow, and I will need to lap it before starting out my honing. I understand the 1in by 1in grid. I have 600 grit and 1500 grit wet dry. I figure I will use both to get a good smooth finish on the stone. I have a sheet of glass for the flat surface. But here is where I am confused. From what I could gather, I need to secure the sandpaper to the glass and then, using an x or figure 8 motion, I run the stone over the secured sandpaper until the grid is gone, and then a few more passes just to be safe. Oh, and the sandpaper has to be wet. Is this all correct? What do you use to secure the paper to the glass? I have heard say of double sided tape, but it seems like the paper would come right off. I am just trying to get a mental image of what this is all supposed to look like.

Matt

Matt,

The suction of the wet paper on the glass will be plenty to keep it from sliding around. Just soak the paper for a minute or two, slap it on the glass and start lapping.

One piece of advice I'd offer is not to be too shy when lapping a new stone. Sometimes they're close to flat and sometimes they're not. It might take a while on the 600 grit paper to really get it flat. You might even find that you need to go to 400 grit or lower if the 600 is taking too long.

Make sure that grid disappears with just a couple of laps before you start to polish it on the higher grit.

Good luck,
Josh

Cool, I will do that. I think I might have enough 400 left over. So you reapply the grid between different grits eh? that makes sense. Thanks for the tips.

Originally Posted by Kentriv

So you reapply the grid between different grits eh?

That shouldn't be necesary. The grid is just to make sure it's evenly flat. When you change grits (and I might suggest you finish with 800 or 1,000) it's just to smooth the finish.

X

Ah I see, I knew the grid was to make sure it was flat, but I was wondering if it was also used as a sort of marker. i.e., whe it is gone, then it is time to move onto the next grit size. But if you just polishing it, then I guess you would go by feel. I will get some 800 and where that takes me. Thanks X.

Matt

Originally Posted by Kentriv

Thanks X.

Say that five times in a row.

X

Matt,

I wasn't clear in my first post: I'd redo the grid a couple of times on the lower grit. Sometimes the slurry or tiny movements in the sandpaper can remove the grid before the stone is truely flat. The slurry fills the gap between the sandpaper surface and the stone, and sometimes it's just enough to make those pencil marks fade.

The important thing is to make sure the pencil marks disappear with just a few laps, because that's not enough for the slurry to remove them. Make sense?

Also, don't press down on the stone too much. Maybe use a little downward pressure initially, but then just hold the stone and move it around with its own weight providing the pressure. I don't know if the stones can bend or flex, but it seems like downward pressure keeps it from wearing evenly.

Josh

Josh

Ah, ok now I see what you meant, got it. Thanks again guys, this has really helped to clear up some stuff in my mind.

Usually on the 8K side when I finish lapping and hold the stone up and look along it at a very shallow angle I can see its surface reflects like a mirror very slightly. Then I know its ready for action. The 4K side is just real smooth.

If you ordered a new Norton, you will get directions on how to lap and use the hone. I've had pretty good success with the manufacturers directons.