[pure-silver] Re: Adding Sodium Sulfite to Sodium Thiosulfate.
- From: "BOB KISS" <bobkiss@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Tue, 5 Apr 2011 10:38:10 -0400
Small error,
Below in the first sentence of the first paragraph I meant to say
that the alkaline salts in standard devs raised the pH. In the second
sentence of the first paragraph I did have it right.
And Richard does point out that Amidol will continue developing even
in a weak acid environment.
CHEERS!
BOB
-----Original Message-----
From: pure-silver-bounce@xxxxxxxxxxxxx
[mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of BOB KISS
Sent: Monday, April 04, 2011 6:11 PM
To: pure-silver@xxxxxxxxxxxxx
Subject: [pure-silver] Re: Adding Sodium Sulfite to Sodium Thiosulfate.
DEAR MICHAEL,
I seem to recall (so I checked my Adams book) that his formula for
Amidol developer did not contain any alkaline salt accelerators (Sodium
carbonate, Borax, etc) which lowered the pH except Sodium Sulfite which
acted more as a preservative than an alkaline agent. So acid stop bath is
not much more effective in stopping Amidol developer than water because
there is no alkaline accelerator to neutralize...which is how stop bath
works with standard, higher pH developers.
I say this under correction by those with more knowledge than I
(Eric Neilsen, Mike Ware, etc) but I think it is so.
CHEERS!
BOB
-----Original Message-----
From: pure-silver-bounce@xxxxxxxxxxxxx
[mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of Michael A. Smith and
Paula Chamlee
Sent: Sunday, April 03, 2011 9:16 AM
To: pure-silver@xxxxxxxxxxxxx
Subject: [pure-silver] Re: Adding Sodium Sulfite to Sodium Thiosufale.
Ah, I did misread the 480. It was not sulfite, but
thiosulfate.
The developer I use is Amidol. Using a water bath
as a stop bath is not an option, as Amidol is such
a strong developer that development would continue.
The Bisulfite makes the fixer slightly acidic,
which, to my knowledge, insures that it keeps
active throughout a printing session, which could
involve sending 100 8x10 sheets though the first
bath of 1/2 gallon of fixer. We have never had the
fixer go bad during a printing session, and we
always use the second fixer to make the first
fixer. So, rather than the acid deteriorating the
fixer, it seems to preserve it.
In re-reading Richard's response, it would seem
that for us at least, a slightly acidic fixer
would be needed to insure neutralization of our
very strong developer.
Also, following what Brett did (the only
photographer I have ever seen making a print), I
put the print in the stop bath for only 10 or 15
seconds. Then into the fixer. After 30 seconds in
the fixer I turn on the viewing light. Evaluate
the print, and if it is a keeper, it goes back
into the fixer for an additional 3 1/2 minutes,
before going into the holding bath. The second
fixer is for 4 minutes also.
Michael A. Smith
On 4/3/11 8:37 AM, Richard Knoppow wrote:
>
>
> -----Original Message-----
>> From: "Michael A. Smith and Paula
Chamlee"<michaelandpaula@xxxxxxxxxxxxxxxxxxx>
>> Sent: Apr 3, 2011 5:13 AM
>> To: pure-silver@xxxxxxxxxxxxx
>> Subject: [pure-silver] Re: Adding Sodium Sulfite to Sodium Thiosufale.
>>
>> 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
>>
> I think you misread Bogdan's post, it was sodium _thiosulfate_. 240
grams per liter is about standard. I have not heard of using sodium
bisulfite in fixer but it would probably serve as well as sulfite but would
be somewhat acid. Sulfite and bisulfite for a buffer at near neutral pH. Not
important for fixer because it doesn't care about pH but acid will tend to
decompose it which is why a large amount of sulfite (15 grams per liter
typically) is used in hardening fixers using white or chrome alum both of
which must be quite acid to be effective. Where there is no added acid about
5 grams of sulfite is sufficient to prevent staining due to carried over
developer.
> I am not surprized that Paula doesn't like the bisulfite mixture
because it is probably emitting sulfur dioxide, the same stuff that gives
hardening fixers their sharp odor.
> No acid it necessary if hardener is not used _and_ the developer is
washed out. A plain water stop is OK provided it is sufficient to wash the
developer out quickly and thoroughly so that it does not continue to work in
the fixing bath. An acid stop will stop the developer but any which carries
over into the fixing bath will tend to react with the thiosulfate.
> The conventional acid stop and acid fix prevents a number of
troubles but has a set of vices all its own as does not using them. Alkaline
fixing baths serve no purpose whatever.
>
>
>
> --
> Richard Knoppow
> dickburk@xxxxxxxxxxxxx
> Los Angeles, CA, USA
>
============================================================================
=================================
> To unsubscribe from this list, go to www.freelists.org and logon to your
account (the same e-mail address and password you set-up when you
subscribed,) and unsubscribe from there.
>
============================================================================
=================================
To unsubscribe from this list, go to www.freelists.org and logon to your
account (the same e-mail address and password you set-up when you
subscribed,) and unsubscribe from there.
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 6011 (20110403) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
============================================================================
=================================
To unsubscribe from this list, go to www.freelists.org and logon to your
account (the same e-mail address and password you set-up when you
subscribed,) and unsubscribe from there.
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 6016 (20110405) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your
account (the same e-mail address and password you set-up when you subscribed,)
and unsubscribe from there.
Other related posts:
