[pure-silver] Re: Fixer Stain Removal
- From: Jean-David Beyer <jeandavid8@xxxxxxxxxxx>
- To: pure-silver@xxxxxxxxxxxxx
- Date: Mon, 09 Nov 2009 05:54:04 -0500
Richard Knoppow wrote:
----- Original Message -----
From: "Ralph W. Lambrecht" <info@xxxxxxxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Sunday, November 08, 2009 4:21 PM
Subject: [pure-silver] Fixer Stain Removal
What is the latest wisdom on removing fixer stains? I've
tried a 50%
citric acid solution with limited success but like to get
something
more 'agressive'.
Regards
Ralph W. Lambrecht
Describe the stains. If they are silver stains you may
have success by using fresh acid rapid fixer with added
citric acid, about 15 grams per liter. This is a mild
solvent for metallic silver. For sulfide stains I think one
has to resort to stronger bleaches like Kodak TC-3.
Solution A
Water 1.0 liter
Potassium permanganate 2.0 grams
Sulfuric acid (concentrated) 4.0 ml
Store in a stoppered bottle away from light.
Solution B
Water 1.0 liter
Sodium bisulfite 30.0 grams
Sodium sulfite, desiccated 30.0 grams
It appears that the sodium metabisulfite of commerce is the
same substance as called sodium bisulfite in Kodak formulas.
To use treat stains with a small amount of Solution A, then
rince well and treat with solution B. Then wash.
I will look at some other sources for clothes specific stain
removers.
If I remember my chemistry correctly (about 50 years ago),
you cannot purchase sodium bisulfite because it does not exist in solid
form. Sodium metabisulfite is readily available in solid form and
absorbs water to become sodium sulfite when mixed with water. Wikipedia
does not hold this opinion and describes each. the bisulfite one is
HaHSO3 and the metabisulfite is Na2S2O5. In other words, they are really
the same compound, but the one is a dessicated form of the other and
perhaps both exist in the dry state. Now what you have if you cannot
keep them both dry enough is anybody's guess, probably a mixture of each.
We should from what substance the O.P. wishes to remove the stains. If
it is something like a metal tray, or perhaps even a plastic tray, TC-3
would be fine, but if it is on clothing, that may be too strong and
damage it.
--
.~. Jean-David Beyer Registered Linux User 85642.
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