rapid, non-hardening alkaline fixer, questions on formulae

Discussion in 'Darkroom Developing and Printing' started by Shakti V. via PhotoKB.com, Oct 8, 2006.

  1. Shakti V. via PhotoKB.com

    John Guest

    Haist wrote that the prints should be fixed for 3~5 minutes in each
    bath. I'm assuming that the 3 minutes would be for fresh fixer. He
    also states that there is a 10 minute max for the fixation of prints
    "as the silver image of many photographic papers is especially
    susceptible to attach by the thiosulfate."

    ==
    John S. Douglas
    Photographer & Webmaster
    Legacy-photo.com - Xs750.net
     
    John, Oct 12, 2006
    #21
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  2. Shakti V. via PhotoKB.com

    John Guest

    Definitely not !

    ==
    John S. Douglas
    Photographer & Webmaster
    Legacy-photo.com - Xs750.net
     
    John, Oct 12, 2006
    #22
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  3. Shakti V. via PhotoKB.com

    John Guest

    Could you provide documentation supporting this ? In reviewing Haist'
    Modern Photographic Processing Vol. 1 pages 634 ~638, Haist expounds
    on the effects of pH and hardeners on the removal of thiosulfate and
    silver thiosulfate complexes. I find particular interest in :

    "Below the isoelectric point (pH=4.9) the gelatin is positively
    charged, and this charge attracts and holds negative ions such as
    thiosulfate or silver thiosulfates. Above pH 4.9 the gelatin is
    negatively charged. The thiosulfate ions are no longer retained, but
    positive ions, such as sodium or potassium, are then held by the
    gelatin. The acidity or the pH of the fixing bath compositions is
    fixed by the chemical balance to secure optimum fixation rate,
    hardening and exhaustion life, as well as avoiding conditions that
    promote sulfurization or sludging. A number of practical fixing baths
    were studied by Crabtree, Eaton, and Muehler, who related hardening
    and solution pH to washing effectiveness.

    The removal of thiosulfate by washing increased as the pH of the
    fixing bath increased to pH 4.9. At pH values above 4.9 the
    thiosulfate was not retained. The chrome alum fixing bath has the
    lowest pH (3.1), but the retention of thiosulfate by films fixed in
    this bath was comparable to the results given by the nonhardening F-24
    fixing bath of pH 5.6. This indicated that the effect of pH of the
    fixing bath is of primary importance when the bath contains potassium
    alum as the hardening agent. With photographic prints the rate of
    washing differed only during the very first minutes, after which the
    rate was the same regardless he composition of the fixing bath. The
    washing photographic prints involves other factors that influence the
    removal of thiosulfates from the photographic materials."

    On page 638 the text states :

    "... but as soon as the pH exceeds 4.9 these last traces of silver and
    hypo can be readily washed away."

    It looks to me like the three important factors in washing are :

    1) Use of a hardener.
    2) Use of a fixer with a pH lower than 4.9.
    3) The use of a wash aid (not discussed here)

    ==
    John S. Douglas
    Photographer & Webmaster
    Legacy-photo.com - Xs750.net
     
    John, Oct 12, 2006
    #23
  4. Shakti V. via PhotoKB.com

    dan.c.quinn Guest

    IIRC his second fix was the plain fix. He did do much of
    his work at a time when emulsions were not so pre-prepared.
    With today's included hardeners a mildly alkaline first and
    second bath fix works just fine.
    Now then what would a discussion of fixer be without my
    mentioning the Very Dilute, One Shot, Single Bath, Archival Fix?
    More important than the chemistry's capacity for silver in the
    presence of some or a combination of halides is the volumeteric
    capacity for silver of a working strength solution. Commercial
    or Archival, the volumeteric capacity falls far short of the
    usual working strength fixer's chemistry capacity. Dan
     
    dan.c.quinn, Oct 12, 2006
    #24
  5. Shakti V. via PhotoKB.com

    Digitaltruth Guest

    The results we publish here
    http://www.digitaltruth.com/store/silvergrain-fixandwash.html are
    derived from testing (conducted by Ryuji Suzuki) for residual hypo
    after single-bath fixation in Silvergrain Clearfix Alkaline Fixer. The
    published washing times are greater than they times we were able to
    achieve, as they include built-in margins for variation in water
    quality etc..




    Haist's study is based on hardening fixers, and only includes F-24 as
    an example of a non-hardening fixer. In his examples he points out that
    there is no residual thiosulfate content after a 10 minute wash in a
    fixer with a pH above 4.9. Clearfix Alkaline has a pH buffered at 7.7,
    so is in complete accordance with Haist's analysis. As you point out,
    on p. 635 he clearly states: "The removal of thiosulfate by washing
    increased as the pH of the fixing bath increased to pH 4.9. At pH
    values above 4.9, the thiosulfate was not retained." Table 1 on the
    same page supports this assertion, although the baths being compared
    are not that useful for this discussion.

    Haist does not include a comparison of modern non-hardening rapid
    fixers (acidic) with similar alkaline materials, but the fact that
    alkaline fixers help avoid the retention of thiosulfate is clearly
    evident. For comparison, if you look at Ilford's data for Hypam fixer
    (non-hardening, pH 5.0-5.5), the recommended washing time for FB paper
    is 60 minutes (without the use of a washing aid). In the case of
    Clearfix Alkaline Fixer, we recommend a washing time of only 20 minutes
    in the same circumstances, based on our own tests for residual hypo. I
    have no doubt that Ilford have done their homework too, and their tests
    showed that this additional time was necessary. Similar times are
    published by Kodak and other manufacturers for their own acid fixers,
    which supports this assertion.

    Another problem, which Haist points out throughout the text, is that
    carry-over developer or stop bath can influence the pH of the fixing
    bath. Clearfix Alkaline is particularly resistant to increases in
    acidity as it uses a buffering system which is designed to be more
    effective than that employed by other commercial alkaline fixers, and
    actually allows for the use with an acid stop bath.


    --Jon Mided

    Digitaltruth Photo
    http://www.digitaltruth.com
     
    Digitaltruth, Oct 12, 2006
    #25
  6. Shakti V. via PhotoKB.com

    Lloyd Erlick Guest

    On 12 Oct 2006 03:25:28 -0700,



    October 12, 2006, from Lloyd Erlick,

    You mean the VDOSSBA Fix?? Who could forget
    such a catchy moniker ...

    regards,
    --le
     
    Lloyd Erlick, Oct 12, 2006
    #26
  7. Shakti V. via PhotoKB.com

    Lloyd Erlick Guest



    October 12, 2006, from Lloyd Erlick,

    I'm not in any position to dispute this, but
    I'm very skeptical that anyone has actually
    seen bleaching of the image after only ten
    minutes in fixer.

    I wonder if anyone has ever done tests with
    real prints and various strengths of
    thiosulfate solution, to see what
    concentration and length of soaking were
    needed to bleach a print in the real world.
    I'd guess it would be quite a long soak,
    hours not minutes.

    regards,
    --le
    ________________________________
    Lloyd Erlick Portraits, Toronto.
    website: www.heylloyd.com
    telephone: 416-686-0326
    email:
    ________________________________
    --
     
    Lloyd Erlick, Oct 12, 2006
    #27
  8. Shakti V. via PhotoKB.com

    Lloyd Erlick Guest

    October 12, 2006, from Lloyd Erlick,

    Well, there's no question I'm a Richard K.
    groupie, too!

    I have always liked Richard's depth and
    breadth of knowledge in an area that
    interests me. But in addition to that, I've
    always tried to emulate Richard's
    level-headedness. I'm here for photography;
    distractions like ego, personality analysis,
    personal invective, character assassination,
    etc and blah blah blah, just have no place
    here as far as I'm concerned.

    This forum has no prerequisites for
    admission, so expertise in any area
    whatsoever is not necessary. Anyone and
    everyone can be expected to appear. This
    forum is also international, so no
    participant should be surprised or dismayed
    at widely varying levels of skill at using
    Usenet, using the English language, using a
    keyboard, and more etc, etc. Spelling errors,
    typos, grammatical errors (grammar - there's
    a subject to argue about! just leave me
    out...)

    When the fateful typo of 'sulfide' instead of
    'sulfite' was made, I happened to be out at
    the corner waiting for the streetcar
    (tram...). Its steel wheels were squealing
    against the steel rails as it turned, but
    still, I'm pretty sure I heard the gnashing
    of Richard's teeth.

    regards,
    --le
    ________________________________
    Lloyd Erlick Portraits, Toronto.
    website: www.heylloyd.com
    telephone: 416-686-0326
    email:
    ________________________________
     
    Lloyd Erlick, Oct 12, 2006
    #28
  9. I am currently printing now and don't have the time to make a long reply, but
    thank you
     
    Shakti V. via PhotoKB.com, Oct 12, 2006
    #29
  10. I am currently printing now and don't have the time to make a long reply.

    Thank you for your informative responses. I am currently using a neutral to
    slightly alkaline fixer (formula by Suzuki), fix for 2 minutes(FB print), and
    I'm now washing the first enlargement (30 minutes). I intend to skip the
    hypo clearing agent. Just as added information for you to understand my
    workflow in context, I use 1% (half-strength) stop bath. If something is
    wrong with my workflow, please let me know.

    It is my aspiration to know as much or close to what people here know, in
    Time. You bless me with your knowledge. Salamat.
     
    Shakti V. via PhotoKB.com, Oct 12, 2006
    #30
  11. Shakti V. via PhotoKB.com

    brownt Guest

    And you don't speak English so well "Nailer". There's no such word as
    "advices".
    And, "Nailer" can you not be such a coward by having your posts removed
    from the archives? And not use a phoney name?

    There's more good information in Richard's stool than you've ever
    posted here!

    TB
     
    brownt, Oct 12, 2006
    #31
  12. Shakti V. via PhotoKB.com

    Tom Phillips Guest

    Well. there is _one_ prerequisite: posts should be
    on topic related to "film developing, printing from
    film, toning, alternative chemistries etc..."
    (paraphrased from the charter.)

    Course many of us have frequently wandered off topic,
    but Richard far less rarely. In fact, it might be
    considered an aberration when he does ;)
    And so they do. By and large though there's still
    enough truly encyclopedic posters/researchers like
    Richard et al. to make reading worth while...
     
    Tom Phillips, Oct 12, 2006
    #32
  13. Shakti V. via PhotoKB.com

    Tom Phillips Guest

    When I worked in a college photo lab it wasn't
    uncommon for some students (mainly the "art"
    type rather than the technnically anal type...)
    to simply leave their prints in the fix while
    attending class. I never noticed it had much
    effect on their images: might have been an
    improvement. In any case, I doubt 10 minutes
    would precipitate bleaching, but likely depends
    on the concentration + paper emulsion type,
    especially with a rapid fix @ film strength.

    Simple enough to test though. Four work prints
    w/gray card fixed for 10, 20, 40, & 60 minutes
    and then check the RDs.
     
    Tom Phillips, Oct 12, 2006
    #33
  14. Shakti V. via PhotoKB.com

    dan.c.quinn Guest

    That's the one though I've not yet made it official.
    The SBOSVDA fix may be even easier to remember.
    I think my A. Thio. concentrate may have weakend
    over the years. My S. Thio. penta and anhydrous have
    been in stock longer. Even though, it is likely they have
    retained full strength. A point worth mentioning; long
    lived dry chemistry. Dan
     
    dan.c.quinn, Oct 13, 2006
    #34

  15. I fixed some test prints before for more than the recommended time. My paper
    was Forte FB Polywarmtone museum weight. I fixed with Kodak Rapid Fix (when
    it was still available here) for more than 15 minutes. Beyond 30 minutes,
    there is already a visible change in tone and bleaching.
     
    QueenAdelle via PhotoKB.com, Oct 13, 2006
    #35
  16. Shakti V. via PhotoKB.com

    Tom Phillips Guest

    I'd would think some bleaching would occur in
    rapid fix after 15-20 minutes. If you can detect
    it with the naked eye it's probably been in the
    fix twice as long as it should...
     
    Tom Phillips, Oct 14, 2006
    #36
  17. Shakti V. via PhotoKB.com

    John Guest

    Above pH 4.9. I haven' found any conclusive documentation on fixers
    above pH 7.0 which I believe is still the defining line between acidic
    and alkaline, correct ?

    ==
    John S. Douglas
    Photographer & Webmaster
    Legacy-photo.com - Xs750.net
     
    John, Oct 15, 2006
    #37
  18. Shakti V. via PhotoKB.com

    dan.c.quinn Guest

    I've not either. I've only come across Bill Troop's one man band
    playing "High ph Fixer" and his series TF-2, 3, and 4. He himself
    admits that direct evidence is non-existant. Search this NG for,
    ephraums fixer . Refresh your memory.
    I question his suggestion, even recommendation, of not using
    an hca following the use of his or other alkaline fixers. I also would
    like to see some documentation.
    In all fairness, where is the documentation with regard to
    acid fixers; Haist from generations gone by? Dan
     
    dan.c.quinn, Oct 16, 2006
    #38
  19. Shakti V. via PhotoKB.com

    dan.c.quinn Guest

    There is nothing in fixer which could cause bleaching.
    In fact fixers are loaded with reducing agents; sulfite and
    thiosulfate. Neither of the two affect elemental silver.
    There is only one possibility; oxygen. I theorize that
    small amounts of oxygen not absorbed by the sulfite and
    thiosulfate do interact with the silver in the presence
    of the thiosulfate causing it's dissolution. Dan
     
    dan.c.quinn, Oct 19, 2006
    #39
  20. Shakti V. via PhotoKB.com

    Tom Phillips Guest

    Don't know if bleaching/dissolution of silver
    would occur at some point but in my last printing
    session I purposely over-fixed some Kentmere
    bromide for 10/20/40+ minutes with no significant
    or noticable change in the measured RDs.

    So, I would only worry about too much fix+wash times...
     
    Tom Phillips, Oct 24, 2006
    #40
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