Re: Where can I get sodium dichromate?

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From: Judy Seigel (jseigel@panix.com)
Date: 05/11/01-08:16:59 PM Z


On Sat, 12 May 2001, Sandy King wrote:
> .... And yes, develoment is more or less
> pre-set, though I can adjust for overexposoure of up to about two steps by
> increasing the temperature of the develoopment bath and/or adding an
> alkali to the water (this softens the gelatin and opens it up allowing the
> pigment to get out). Use of an alkali might also work with gum?

Yes, an ounce or so of household ammonia in the tray of water gives
over-exposed print a push. Ammonia in HOT WATER gives a REALLY BIG push.
This will often/usually rescue students' overexposed prints, but once they
get the range, rarely needed. (Sodium carbonate apparently does same
thing, though ammonia is easier -- already dissolved.)

Judy


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