Thread: how do I lap a stone?

You do really need to lap that Norton. They are really rough surfaces when new.
I found that I had to lap more than just what was needed to get it flat.
Once I got mine flat which I proved by removing the penciled grid drawn on the stone, I needed to remove at least that much more material to get it feeling equally smoth all over its surface.
The 8000 side diidn't require as much sanding as the 4000 side. From what is on the forum i beleive that is the norm.
I initially used the countertop to lap with but now I bring out a piece of granite countertop that I had made to use as a baking stone. Wet and dry sandpaper works well enough and is cheap. 3M or Norton papers seem to be of higher quality and will outlast most of the others that I have tried. 360 and 400 grits have worked well for me. Circles or X rubbing patterns seem to work faster. Lighter pressures will result in more work performed with less wear to the paper as heavy pressure breaks loose many of the abrasive particles before you get them worn down.
I think you will like the Norton. I have been very happy with the performance of mine.
You might very well also be quite pleased with the performance of those inexpensive razors if they are old ones. The cheap new stuff has a reputation for being very inconsistant in steel quality and overall workmanship.

Are you guys serious about using granite countertops? How so?

Originally Posted by ccase39

Are you guys serious about using granite countertops? How so?

We would never lie to you!!!

You need that stone to be as flat as possible. If its dished in any way, You'll have a harder time with your honing. Also that fresh surface you bring up will cut a lot nicer then the surface from the factory. I find a fresh surface when I'm honing is a must. lets me "feel" what I'm doing better. You should search more info at the top there in the search bar. I have limited experience and there's more threads with info from very experienced guys on this subject.

I have a relatively new Corian counter top which is around 3/8" thick. It seems stable enough but when when applying much pressure on it I can feel it flexing. I used that surface to lap on for months and got reasonably good results.
The piece of granite I use is 3/4"
thick and being solid rock it just doesn't flex.
I just lapped an antique 5" X 2 3/8" Coticule on it and the reflexions off it are absolutely perfect all the way out to the edges.
Do you absolutely need a perfectly flat lapped stone to sharpen a razor? No you don't. However, if you want to sharpen a razor to as perfect and sharp an edge as possible, then using a stone that is as flat as possible definately gives you an advantage.
When using pressure on the blade while sharpening the blade will flex a little and will follow a stones irregularities.
When you are finishing up on a stone your last few passes are with minimal pressure.
This is where the irregularities of flatness of the stone will leave you wanting.

Originally Posted by Galaxy51

I have a relatively new Corian counter top which is around 3/8" thick. It seems stable enough but when when applying much pressure on it I can feel it flexing. I used that surface to lap on for months and got reasonably good results.
The piece of granite I use is 3/4"
thick and being solid rock it just doesn't flex.
I just lapped an antique 5" X 2 3/8" Coticule on it and the reflexions off it are absolutely perfect all the way out to the edges.
Do you absolutely need a perfectly flat lapped stone to sharpen a razor? No you don't. However, if you want to sharpen a razor to as perfect and sharp an edge as possible, then using a stone that is as flat as possible definately gives you an advantage.
When using pressure on the blade while sharpening the blade will flex a little and will follow a stones irregularities.
When you are finishing up on a stone your last few passes are with minimal pressure.
This is where the irregularities of flatness of the stone will leave you wanting.

How does that smooth of a surface smooth out a stone? I would figure it would need to be abrasive.

Sorry! I forgot to state that the granite is the base that you put the sandpaper on so the paper lays absolutely flat.
Wet the granite so that suface tension of the water will hold the paper in place.
3M and Norton really make good sandpaper. Get one of those brands if you can.
I just tried GatorGrit that is made in Finland and it wanted to curl up into a roll instead of laying flat!
Another good thing about the granite and sandpaper is that the paper is replaceable. If you want to try a coarses or finer grit to see how that effects your hone you can do so.
Also, because the sandpaper does the work, the granite will never wear out.
It would be very nice of you to get mama a "baking stone" for Christmas.

Thanks for all your help guys. I got some waterproof sandpaper and after following your advice and watching multiple videos I tried my hand at lapping my new Norton. I could not believe the difference. It is much smoother now than when it arrived from the factory. Im gonna wait a while before I start honing but I like to have all my guns cocked and loaded.