-------- Original Message --------
Subject: [pure-silver] Re: Adding Sodium Sulfite to Sodium Thiosufale.
From: Bogdan <
bkarasek@xxxxxxxxxxxx>
Date: Sun, April 03, 2011 5:55 am
To:
pure-silver@xxxxxxxxxxxxx
Cc: "Michael A. Smith and Paula Chamlee"
<
michaelandpaula@xxxxxxxxxxxxxxxxxxx>
Thank you for the input, Michael. I'll see about the Sodium BiSulfite although I have Sodium Sulfite readily available. Anchell's recommendation is for 480 gr of Sodium
thiosulfate per 2 L of water.
Cheers,
Bogdan
On 4/3/2011 8:13 AM, Michael A. Smith and Paula Chamlee wrote:
Bogdan,
I use an acetic acid stop bath. I then use plain sodium thiosulfate with 15-25 grams added of Sodium Bisulfite per 1/2 gallon or 40-50 grams of Sodium Bisulfite per gallon.
Many years ago, when I spent a month with Brett Weston, watching him print most every day, this is what he used. I figured if it was good enough for Brett, who learned to do this from his father, it was good enough for me.
Brett used the higher number in the quantity range above. Paula does not like the smell of the Bisulfite when she gets close to it, so she has cut down the quantity with no adverse affect.
When the Bisulfite is not used, and there is only the plain sodium thiosulfate, the solution soon gets quite cloudy (though seems to continue working). When the Bisulfite is added, it clears right up.
I use a two-solution fixing bath. The first bath only gets the Bisulfite. Then I use a holding bath and at the end of the day I rotate finished prints through a second fixing bath, this time with plain sodium thiosulfite only and no Sodium Bisulfite.
I then take the prints directly into a Perma=Wash/Rapid Selenium Toner Solution. I have never had any staining.
Using 480 grams of Sodium Sulfite per two liters of hypo seems to me to be beyond excessive. That is a lot of Sodium Sulfite. Mt recommendation is to ignore Anchell's recommendation.
Michael A. Smith
On 4/2/11 5:48 PM, Bogdan wrote: hi all,
In the discussion on using 2 bath Sodium thiosulfate, someone mentioned adding Sodium sulfite to prolong the keeping properties of simple hypo.
I'm using Anchell's "Darkroom Cookbook" as my reference for my chemistry.
For plain hypo, He recommends 480.0 grams of Sodium Thiosulfate per 2 L of water; how much Sodium sulphite should I add to assure longevity.
Till now, I have never added Sodium Sulfite to the hypo and would tone the prints in 1:9 KRST (no additives) and then wash.
Any suggestions of the amount I should add to the hypo?
Cheers,
bogdan
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