Re: ATM A 100% Sharpie Test?

["Nils Olof Carlin" <nilsolof.carlin@telia.com>]

Dan,

>A crazy thought:  could one spray the entire surface of a fine ground
>mirror, thus filling all the pits with ink, let dry, and then grind
>until *all* the black pits were gone?  It would certainly make finding
>pits much easier...
>Has anyone tried this?


Not I, half an hour ago. But why wonder, if you could do a pilot study? I took two slide 
glasses, beveled the edges with a stone for safety. A few seconds with #150 grit produced 
some nice test pits, to color with a layer of "sharpie" ink. After a wet or two of #400 
grit, I could see with a magnifier some pits were indeed inked, but not all. 
Then the thought struck me - would fluorescent ink be any good, using a UV "blacklight"? 
First try showed my yellow underline pen was water-soluble - so I had to do my next #400 
"wet" with a drop of salad oil instead. With the glass near the UV light, the remaining 
pits were very much more conspicuous this way, so if you could get a water resistant 
fluorescent "sharpie" (I'm sure there must be), the sensitivity of the test would likely 
be very much improved.

And you would know for sure if the large pits are left over from the old, coarse grit or 
are from the new, finer one.

Just a pilot study, any volunteers for a full-scale one? ;-)

Nils Olof

In case you wondered: no UV seems to pass my glasses, at least holding them between the 
light and a paper kills all fluorescence.