[pure-silver] Re: Rodinal
- From: Gerald Koch <gerald.koch@xxxxxxx>
- To: pure-silver@xxxxxxxxxxxxx
- Date: Wed, 2 Mar 2011 17:07:59 -0800 (PST)
As I mentioned Rodinal Special is a conventional developer containing
hydroquinone and a phenidone derivaive. It is slightly yellow and somewhat
syrupy as 1 liter of the concentrate conrains 400 ml of triethanolamine. It
contains no other developing agents according to the label. It is a fine grain
developer due to the action of the TEA as a silver halide solvent. A formula
based on the MSDS was given on a German website a few years ago.
Jerry
________________________________
From: John Stockdale <j.sto@xxxxxxxxxxx>
To: pure-silver@xxxxxxxxxxxxx
Sent: Wed, March 2, 2011 7:11:51 PM
Subject: [pure-silver] Re: Rodinal
>
> I thought Rodinal Special used an oddball developing agent AGFA had a
>patent
>on. It may well have hydroquinone in it but hydroquinone is rarely used as the
>sole reducing agent except in very high contrast developers.
> I think the main virtue of regular Rodinal is its convenience; it works
>for
>nearly any film, makes a decent, if expensive, paper developer, and has very
>long shelf life. OTOH, its not an "optimum" developer for anything; one can
>get
>finer grain or higher speed or both with other developers. Rodinal does work
>well as an acutance developer when highly diluted and may have some
>compensating
>effect (the two often go together).
>
> -- Richard Knoppow
> Los Angeles, CA, USA
> dickburk@xxxxxxxxxxxxx
>=============================================================================================================
>=
>
This is from the old Australian MSDS for Rodinal Special concentrate. The Oz
docs tended to have more detail than those of other countries.
Ingredients Name CAS Proportion
Triethanolamine 102-71-6 30-60 %
Potassium sulfite 10117-38-1 10-30 %
Hydroquinone 123-31-9 1-5 %
Potassium bromide 7758-02-3 1-5 %
EDTA-alkali salt 1-5 %
Phenidone 92-43-3 0-1 %
Water 7732-18-5 (To 100%)
Specific Gravity 1.265.
pH Value Approx. 10.3.
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