Thread: How lap new Norton 4/8

The Norton 4/8K stone arrived today. I have no experience with a quality stone like this. The manual says to lap it with 220 then 400 wet/dry sandpaper on a glass pane. Do I lap it under running water or dry lap it?

This stone is big and it is heavy. I'm impressed!

I lapped mine with the norton flattening stone but you can use 400 grit wet and dry on a hard smooth flat surface. I used the glass top of my electric stove. Just use a pencil and draw your grid . Soak the stone and paper and keep it lubricated.

All I did to lap my Norton was to rub it against my DMT 325 under running water. I didn't draw a grid. I just went up and down.

In the JaNorton thread is a ton of info on Norton waterstones including a Vid on lapping

I watched your video but I don't have a lapping stone but must fall back on sandpaper and a glass pane. Do I put everything under water to lap, just soak them wet or dry lap?

Soak the Norton in water about 10 minutes. Wet the sandpaper front and back and set it on the glass. Mark a grid on the stone, and rub it back and forth on the sandpaper. When the stone starts to stick to the paper, splash some more water on the paper.

For a new stone, start with coarse paper because fine takes a LOT longer. But finish with fine - otherwise the surface of the stone will be flat, but not smooth.

Change the paper every 10 minutes - it won't look worn out, but a new piece will flatten your stone much faster.

I know that Norton make an excellent product.... But.... For the money they charge they can lap there new stones! Flat is flat! It's not that I want a Custom flat with one corner up a little!! I just want it flat. It'n not nature it man doing it.
To me it's like there people that will sell you a razor saying...'oh I'm leaving the old soap and hair and bloom on it because I know you're a collector and want all the gunk on it!
Wrong - wash it off atleast. Same with Norton. 'Sell A Flat Hone!'

After water soaking, I used 2 pieces of 220 on each side, followed by 2 pieces of 400 grit sandpaper on each side of the new Norton 4/8K stone. The scarf really comes off fast at first and then the stone starts to glide like an air hockey puck. I'll go buy 2 more pieces of 220 and 400 and lap it again. I can see low spots on the stone and some corners that will take quite a bit of lapping to smoothe out.