HCA Keeping properties, etc...

Discussion in 'Darkroom Developing and Printing' started by Lew, Jan 8, 2004.

  1. Lew

    Lew Guest

    The keeping property for Kodak HCA working strength in a tray is 1 day. How
    about storing the working strength solution back in a bottle? Does the
    addition of Rapid Selenium Toner affect the keeping properties? Also, other
    than the fact that rc papers don't need HCA, is there any actual harm in
    using it?

    -Lew
     
    Lew, Jan 8, 2004
    #1
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  2. Lew

    Tom Phillips Guest

    My understanding is it (the sulfite) oxidizes fairly quickly, so even
    though storage of working strength solution in a stoppered bottle should
    extend the unused recommended 24 hour tray life, if you've run film
    through it or it's been in a tray for several hours already there's
    likely not much left worth extending by bottling it. Kodak recommends it
    be discarded even if not exhausted.
    No. Toner works in HCA and vice versa. Should thus have no effect.
    No harm but no real need, since RC papers don't absorb fixer except
    maybe a little around the edges and wash times are already short. The
    only reason you use it with FB papers (and film) is to dislodge through
    ion exchange residual fixer bonded to the fibers, since otherwise you
    have to wash for long periods of time.
     
    Tom Phillips, Jan 8, 2004
    #2
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  3. KHCA is mostly Sodium Sulfite. When exposed to air sulfite oxidizes
    to sulfate. While the sulfate will do no harm it is not a very
    effective wash aid. Putting diluted KHCA into a closed bottle will
    extend its life but not by enough to make it worthwhile. KHCA is an
    expendible as are most photo chemicals.
    Adding Rapid Selenium Toner does NOT extend the life of the wash
    aid. When it is recommended to dilute KRST in wash aid its is because
    at high dilutions, say 1:20, the Selenium will be exhausted in about
    the same rate as the wash aid. The idea is to save time by combining
    the two treatments. Since it has been shown that high dilutions of
    current KRST are not completely effective in protecting images this
    procedure probably no longer has utility. Stronger dilutions of KRST
    should be made with water and the wash aid used as a separate
    treatment before toning.
    KHCA works by displacing thiosulfate ions from the emulsion and
    also the support of fiber papers. The emulsion of RC paper is so thin
    that it washes out to archival values in four minutes even when fixed
    in a hardening fixing bath. The problem with using KHCA or other wash
    aid on RC paper is that it may wash out too much. Some forty years ago
    it was discovered that a very small amount of residual thiosulfate
    left in the emulsion stabilized the image silver so that it does not
    so readily oxidize due to peroxides in the atmosphere. While this
    protection is not as effective as toning nonetheless it is significant
    and the life of film and both fiber and RC papers are extended by not
    overwashing.
    Sometimes getting all of the thiosulfate out may be necessary, as
    when toning in some toners. When this is so treating RC in a wash aid
    may be helpful. I've toned RC in all of the common toners and never
    had any problem but that's only me.

    Richard Knoppow
    Los Angeles, CA, USA
     
    Richard Knoppow, Jan 8, 2004
    #3
  4. Lew

    nick Guest

    Richard,

    Your comment about SRT exhaustion startled me. I tone almost
    everything in 1:15 for 2 minutes for aesthetic, not archival, reasons.
    The tray is filled as automatically as the fixer. I mix up about 45
    ounces at a time and reuse it for at least a couple of weeks, working
    about 16-20 hours a week. I dump it every so often while I am still
    seeing the color changes it imparts. I have found that the stronger
    solutions, 1:7 and 1:5 don't last as long even though they are not
    used daily. With those I use a sniff test and dump when I think they
    are weakening.

    Nick
     
    nick, Jan 9, 2004
    #4
  5. Lew

    lloyd Guest

    On 9 Jan 2004 03:14:34 -0800,
    (nick) wrote:

    I have found that the stronger

    jan904 from Lloyd Erlick,

    It's strange that the higher concentrations of
    selenium toner do not last. I find exactly the
    opposite. My 1+5 dilution of the Kodak version of
    selenium toner (KRST) seems to keep indefinitley.
    It gets used up primarily by solution carry-out on
    the sheets as they are processed. I top up my jug
    of KRST at intervals (I try to keep it up to about
    three liters, since that is a comfortable level
    for me). I've been topping up my present bath of
    KRST for more than two years now. It seems to keep
    indefinitely. I have found that eliminating acid
    from my print processing line causes my KRST to
    remain almost water clear. I filter it frequently
    with paper coffee filters. The smell of KRST is
    ammonia. It is most intense when first mixed, and
    gradually abates as the solution ages. I've never
    noticed a relationship between intensity of odor
    and intensity of toning action.

    regards,
    --le
    ______________________________
    Lloyd Erlick Portraits, Toronto.
     
    lloyd, Jan 9, 2004
    #5
  6. Lew

    David Starr Guest

    Since I went "acid-free" I'm doing the same, but it's only been 6
    months so far. :)

    BTW, Lloyd, I tried your "hang 'em up" method of drying FB prints.
    it's GREAT!! I get a very slight curve overall, about 1/8", and a
    couple of ripples on the edges. Two days under weights & they're
    flat. Thanks for the tip.


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    David Starr, Jan 9, 2004
    #6
  7. Lew

    Lew Guest

    So what do you guys do for stop baths and fixers?

    -Lew
     
    Lew, Jan 10, 2004
    #7
  8. Lew

    nick Guest



    Lloyd,

    I loved your answer. My stink test is I quess irrelevant. I never
    dumped the stuff because it failed , but it seemed simpler to do so
    periodically than to be aggravated by unpredicable resuls. Being too
    lazy to run tests on this process I'll take you word. Acid for me is
    a non issue as I was taught over 30 years ago to use a rinse of Kodalk
    before a second fix and that works fine.

    Next. What do you mean by "topping off?"
    do you toss in little more concentrate as the volume drops or what? If
    it is quick and easy I'll buy it.

    Nick
     
    nick, Jan 10, 2004
    #8
  9. Lew

    lloyd Guest

    On 9 Jan 2004 22:42:35 -0800,
    (nick) wrote:
    ....

    jan1004 from Lloyd Erlick,

    'Scuse the Englishism! It's probably not real
    English either, come to think of it. I did mean
    that I add more freshly prepared 1+5 solution (or
    whatever is the appropriate dilution) to restore
    it to the appropriate volume. Easy and quick.

    I use most baths in three liter size. To mix up
    three liters of KRST at 1+5 dilution (500 ml
    concentrate plus 2500 ml distilled water) costs me
    about C$15. That's around USD10 these days. That's
    way to much for me to toss casually, or even for
    me to watch turn murky black-brown with some sort
    of crud over a fairly short period, only a few
    weeks. I find the murk does not occur if there is
    no acid in my process (which is different from
    acid rinsed and neutralized with Kodalk. I tried
    that and it is much less effective than simple
    removal of acid from the line.)

    In place of stop bath I use a quadruple tap-water
    rinse for both prints (fb) and film. In place of
    an acid fix I use the "plain fix" Ansel Adams
    describes in "The Print". It contains water,
    sulfite and sodium thiosulfate only, no acid.

    I wrote a huge pontification upon this subject and
    put it on my website. It's under the 'technical'
    heading in the table of contents.

    regards,
    --le
    ______________________________
    Lloyd Erlick Portraits, Toronto.
     
    lloyd, Jan 10, 2004
    #9
  10. Lew

    Lew Guest

    Nick:
    Would you mind explaining the use of Kodalk, please?

    -Lew
     
    Lew, Jan 10, 2004
    #10
  11. Lew

    Lew Guest

    Lloyd:
    How do you actually manage the 4x tapwater rinse? 4 trays between the
    developer and fixer? How often do you replace the water during a single
    printing session?

    -Lew
     
    Lew, Jan 10, 2004
    #11
  12. Lew

    David Starr Guest

    Stop bath - running water in a tray for 60 seconds for prints, Fill,
    agitate a few seconds & dump - 5 changes - for film.

    Fixer - Formulary TF-4 for both.


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    David Starr, Jan 10, 2004
    #12
  13. Lew

    David Starr Guest

    I'm not Lloyd, but I use a tray with holes drilled in one end. Holes
    are sized to get a pretty rapid flow out of the tray. I have a hose
    in the tray with water running in all the time. Sixty seconds in
    there with vigorous agitation does the job.


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    David Starr, Jan 10, 2004
    #13
  14. Lew

    lloyd Guest


    jan1104 from Lloyd Erlick,

    I use the single-tray method, so no lineup of
    trays. (I have an article on my website about
    this.)

    I fill the tray, agitate, and dump, four times. I
    prefer this to the smell of acetic acid or sulfur
    dioxide. (Sulfur dioxide forms when sodium sulfite
    and acid meet. Developer dribbles meeting stop
    bath dribbles in the sink cause small whiffs of
    sulfur dioxide from time to time. It stops me in
    my tracks.)

    regards,
    --le
    ______________________________
    Lloyd Erlick Portraits, Toronto.
     
    lloyd, Jan 11, 2004
    #14
  15. Lew

    Dan Quinn Guest

    RE: (nick) wrote
    That's a new one, a Kodalk rinse between fix one and fix two. Is fix
    two acid when fresh? If not, what sort of a fix is it? Dan
     
    Dan Quinn, Jan 11, 2004
    #15
  16. Lew

    lloyd Guest


    jan1104 from Lloyd Erlick,

    I think it's Adams who describes a print
    processing sequence that stores up the prints in a
    holding tray after the first fix, which is acidic
    (F-6).

    When finished exposing new prints, the prints done
    are treated with Kodalk. The second fix follows;
    it's a tray of what Adams terms 'plain fix' (can't
    remember if he says fix or fixer), which contains
    no acid. Then they are transferred with no rinse
    to Selenium Toner (the soak and treatment with
    Kodalk are in aid of raising the pH of the print
    to the point where it will not cause staining in
    the selenium. An acidic print is prone to bright
    yellow stains from the selenium toner. Yellow so
    bright it's quite faint and hard to see,
    sometimes.)

    It has often been claimed in the past that
    transferring a print (we're speaking of FB prints
    here...) directly from fix to selenium will cause
    stains. Adams points out that this is so if the
    fix is acidic. The acidity is the culprit, not the
    fix. His 'plain fix' is not acidic.

    After treating the whole batch to selenium toner,
    the prints are ready to wash.

    I find this approach tedious, needlessly labor
    intensive, and tiring. And it makes it virtually
    certain that one will have to shuffle batches of
    prints through a tray of second fix, then Kodalk,
    then toner, ugh. I particularly dislike shuffling
    batches of prints through a tray all together.
    That has always put my heart in my mouth. I hate
    to think of the minute, hard to see scratches that
    are marring the delicate wet faces of my beautiful
    prints. Doing it bare-handed is an unnecessary
    exposure to chemicals. Using gloves just begs the
    audience to jeer: "those gloves clean, Bunky??"

    I've expounded at length about all this in
    articles on my website, under the 'technical'
    section of the table of contents. In a nutshell,
    FB printmaking in the darkroom is way easier,
    quicker and more rigourous (*nothing* whatsoever
    touches the face/image area of my prints while
    they are wet, except processing chemistry and
    rinse water - no hands, gloves, other prints,
    tongs, squeegee, drying screens...) if a single
    tray is used, if no acid is present in any
    processing step, and if prints are hung to air
    dry.

    regards,
    --le
    ______________________________
    Lloyd Erlick Portraits, Toronto.
     
    lloyd, Jan 11, 2004
    #16
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