[pure-silver] Re: Paraformaldehyde/Acetone in lith developers
- From: "Nicholas O. Lindan" <nolindan@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Tue, 2 Mar 2010 00:12:40 -0500
"BILL WILLIAMS" <krbill_10@xxxxxxxxx>
I haven't looked up the 1,4-Dihdroxybenzol to see what it is.
Catechol: the substance that makes apples and bananas turn brown.
It is a natural insecticide, like gallic acid (pyro). When the
fruit is breached and exposed to air the catechol oxidizes and
turns to a polyphenol. The polyphenol then polymerizes the
proteins in the wall of the insect's digestive tract - tan's its
guts.
When used as a developer the compound is used as a mild reducing
agent. When reduced in the process of developing the silver the
resulting polyphenol tans the gelatin - gelatin being animal
protein.
Anti-oxidants are _not_ your friend.
--
Nicholas O. Lindan
Cleveland Engineering Design, LLC
Cleveland, Ohio 44121
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