Judy Seigel wrote:
>
> On Mon, 8 Aug 2005, wcharmon@wt.net wrote:
>
I recall that Sil Horowitz,
> chemist, said that there is no risk to archivality from residual
> dichromate, as it's already oxidized (or like that).
Another way of saying what I just said is that I expect Sil was
referring to dichromate stain that's actually made of reduced chromium,
not dichromate stain that's mostly unreduced chromium, and I think it's
important to make the distinction.
It's an empirical question of course, whether the yellow dichromate
stain would turn brown over time, and could be tested by someone who's
interested, by putting one of these yellow dichromate-stained prints in
the sun and seeing what happens. If it stays yellow, that would be
somewhat astonishing but a good thing to know. I can't test it here
because (1) I don't know how to create the yellow dichromate stain and
(2) the sun seems to have deserted us here at the coast; it is as dull
and grey and dim here as in the middle of winter. My son came for the
weekend to escape the heat inland, but after a couple of days of the
dull grey he fled back to warmth and sun.
Katharine
Received on Wed Aug 10 11:37:26 2005
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