Thread: What is the highest grit you have used on a stone?

I lap all my stones with a 220 dmt lapping plate (not the sharpening plate).

For my higher grit stones i then use sandpaper to remove the scratches left from the DMT. Depending on the stone depends on how high i go. On my Chinese 12k i got to a 400 then to an 800 to give it a glass like feel and i have even tried a 1k (i was told by a few members to get the C12k as polished as much as i can for the best results)

I have both sides of my C12k lapped and the second side i leave with the 220, Both sides feel quite different to sharpen with. The 220 side has a 'zing' sound when using it (if that makes sence) and the polished side has next to no sound when using it. I find the marks in my C12k from my 220 don't disappear but it hold a slurry well and creats a slurry a lot faster then the polished side, i can then transfer some of that slurry across when i flip it.

My shapton 8k and 16k i finish at 600
and most my other stone i finish with a 400 or the 220dmt
I will occasional finish my other 12k stones with a 600 but, at the same time, sometimes the 220 gives it a nice feel different to what the 600 gives.

I have been playing with some new jnats and i have been finishing them with a 1k and even tried 1.5k - i 'think' the 1.5k made a slight difference but not enough to make it worth while. I really should ask one of the pros whats best for lapping the jnats lol but they are supper hard and any marks or scratching takes a long time to disappear!

Still playing and still learning with all my stones. Maybe i will learn something from this thread

Edit: This jnat stone i lapped from a 40 grit lol but it was in really bad condition. I first started with the 220 DMT and when i realised that wasn't working i put in on my belt sander. That didn't do anything so i purchased some 40, 80, 160 grit and so on - Took me 6 hours to get it flat (minus a break here and there and a drive to burnings for some more sandpaper).

But if i had have started with a 40 grit in the first place i think it would have been a 2 hr lap and not a 6 hr lap lol

Originally Posted by Brighty83

Edit: This jnat stone i lapped from a 40 grit lol but it was in really bad condition. I first started with the 220 DMT and when i realised that wasn't working i put in on my belt sander. That didn't do anything so i purchased some 40, 80, 160 grit and so on - Took me 6 hours to get it flat (minus a break here and there).

I find SiC powders on float glass considerably faster. It may be there is no cushioning from the sandpaper but I can't imagine spending 6 hours, even on a hard stone.

Originally Posted by onimaru55

I find SiC powders on float glass considerably faster. It may be there is no cushioning from the sandpaper but I can't imagine spending 6 hours, even on a hard stone.

Its sorta relaxing, once i started to see results. lol. Its not something i would want to do too often.

I have done a google for SiC (silicon carbide powder) powders on float glass but i cant find much. The lowest grit i could find was 120. Do you have a site you recommend of the powders and the glass?

Originally Posted by Brighty83

Its sorta relaxing, once i started to see results. lol. Its not something i would want to do too often.

I have done a google for SiC (silicon carbide powder) powders on float glass but i cant find much. The lowest grit i could find was 120. Do you have a site you recommend of the powders and the glass?

Glass -- a local glass shop.
My grit -- hunt a local astronomy club.

Originally Posted by Brighty83

I have done a google for SiC (silicon carbide powder) powders on float glass but i cant find much. The lowest grit i could find was 120. Do you have a site you recommend of the powders and the glass?

Gem polishing sites are what you want

Tumbling Grit and Abrasives

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