Thread: 320 grit leaving marks

Got 320 grit 3M wet dry to lap my Nortons. It is leaving swirl marks on my 4k8k. Not using too much pressure. Following the directions in the SRP library. I wonder if my razor isn't making full contact with the stone B/C of the swirls. Is this normal? Should I get a finer grit?

Are the stones new?

Are you using water?

Do you thoroughly rinse the paper and the stones before lapping?

Have you tried a different sheet of paper?

Just looking for a source of contamination.

Your razor is more than likely making full contact if the hone is flat. Scratch market from the paper may* effect your edge. My 4k/8k is polished to 2k, but 320 is about as far as most go. The hone probably just needs more time on the paper if they're new. Wet sanding is your friend, dry the enemy.

Also, washing both is good advice. And make sure the surface you lay the paper on is debris free. I ruined my own day one time by not checking that, had debris under the paper and left one heck of a scratch on a newly lapped Norton 4k.

Draw a pencil grid on the hone and do a few laps on the sandpaper and see what it's removing. I lap my Norton before every honing session with a 320 DMT to refresh the surface, they are soft and I don't think they need to be polished unlike other very hard natural finishing stones

I know scratches in synthetic hones get most people upset, but realistically it makes no difference in the hones' function.

Originally Posted by Utopian

I know scratches in synthetic hones get most people upset, but realistically it makes no difference in the hones' function.

I agree! I have scratches on both my 3k and 8k Naniwa stones and it doesn't seem to impact honing in any way.

Totally agree

The only time they could possibly be a problem is if they were horizontal across the hone, vertical ones not a bit of a problem.

Large hills and valleys and anything sticking up is a problem and not little vertical scratches

Originally Posted by Utopian

I know scratches in synthetic hones get most people upset, but realistically it makes no difference in the hones' function.