Dressing Crystolon with Drill Powered Aluminum Oxide?

[J_SAMa]

I had relative success with flattening and India stone on regular wet and dry sandpaper. Took long but it did work. Not so much luck with a Crystolon though... The fine side was alright but it seems that the coarse side was chewing up the sandpaper faster than the sandpaper was flattening it. Tried flattening it against the India only to have the India clogged :evil: Had to redress the India after that...
Now I could just try and use it without flattening but it's sort of clogged too so I have to at least dress it somehow... The only solution I can think of is aluminum oxide grinding sticks in a drill. Probably won't get the thing flat but at least will get it to cut. Am I nuts or has someone else tried doing this already?
While I'm at it, is it normal to get a lot of dust coming off of a fine crystolon? I get more grits coming off of it than I do with a waterstone...

Thank you,
Sam

 

[JohnPW]

Crystolon is silicon carbide and it's harder than aluminium oxide/India so I wouldn't expect aluminium oxide to grind silicon carbide...

I've got some dished Crystolon and India stones that I would love to get flattened but from what I've read you need to use a very coarse diamond stone. Maybe if you have two Crystolon stones you could flatten against each other.

 

[Cheshirechappie]

The 'old fashioned' way was to use half a handful or so of sharp sand (not builder's sand) in a slurry with water on a flat surface such as a piece of glass, and just keep rubbing until it's flat. Cheap as chips. Not quick, though.

If the stone is clogged with old dried oil, it might pay to soak it out in white spirit or kerosene first, though. No amount of flattening will unclog a gunged-up stone.

 

[J_SAMa]

The 'old fashioned' way was to use half a handful or so of sharp sand (not builder's sand) in a slurry with water on a flat surface such as a piece of glass, and just keep rubbing until it's flat. Cheap as chips. Not quick, though.

If the stone is clogged with old dried oil, it might pay to soak it out in white spirit or kerosene first, though. No amount of flattening will unclog a gunged-up stone.

Is it the "silicon carbide powder" you're talking about? Also I have soaked the thing in soapy water but there's still some surface gunge.

 

[Cheshirechappie]

Well - no, not really. I don't know what the chemical composition of 'sharp sand' is, it's just sand in which the grains have sharpish edges rather than the rounder, rolled form that something like beach sand tends to have. A bit like the difference between quarried, mechanically crushed stone and river-rolled stones. Sharp sand is often available (in the UK at least) in smallish bags at garden centres for horticultural purposes, and can be bought by the ton at builder's merchants as 'grit sand', I think; not the soft sand used by builders for making bricklaying mortar, the sort used for laying block paving and making bulk concrete.

I don't see why silicon carbide powder of a suitable grit size shouldn't work as well, or better than, sharp sand, though. Diamond cutters use diamond dust to grind and polish diamonds, so using SiC to cut a honing stone is only the same principle. It'll be slower than using a diamond lapping plate, but a darn sight cheaper.