Thread: edges not flatting !!!!!!

seems like it took me FOREVER to get my norton flat and i was using a DMT325 , my corners about 1/2" in gave me a back ache leaning over the sink !! but after a lot of time it was all even !! although still pretty new to all this i would think you would need to keep hitting it like Martin103 suggest .

When I recently lapped my Norton I had to lower the grit to 180 wet/dry as 2 corners on both the 4K & 8K were slightly lower, & I tried lapping it with 600 grit (all I had at the time) but it was seriously slow work, I ended up putting it down & coming back to it with more agressive sandpaper & then moving to higher grit, finished the 4K with 400 grit & the 8K with 1,000 grit. Once it was really really close I just rounded the edges & called it done. Only tried the 8K side for a touch up & that worked out really well for me.

You can speed up the lapping with 80 grit or even lower sandpaper as long as you take care to finish the process with 180-400-600 and even 1000. I keep some 1500 grit sandpaper around, but usually just use my DMT 325 for routine lapping after honing.

I would suggest also that you always soak the stone in water for the same amount of time. It does make a difference as to how the stone wears or laps.
YMMV
~Richard