Concentrated HCA From Powder

Discussion in 'Darkroom Developing and Printing' started by Alan Smithee, May 24, 2006.

  1. Alan Smithee

    Alan Smithee Guest

    I've got a big 454g packet of Kodak HCA. I don't exactly have room for the 5
    US gallons that it will produce. I've contemplated just weighing out 20 per
    cent and making 1 gallon. Is it possible to make the whole packet into a
    concentrate similar to other manufacturers' (e.g. Agfa 4-in-1), then dilute
    1:31? Thx.
    Alan Smithee, May 24, 2006
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  2. Alan Smithee

    Mike King Guest

    You can mix it as a one gallon or 1.25 gallon concentrate and then dilute
    1+4 or 1+3 for use. The liquid concentrates (with the 1+31 dilution) use a
    different composition. To get the 1+31 dilution ratio from concentrate you
    would need to dilute the whole package in 20 ounces of water (someone check
    my math it's still early here).
    Mike King, May 24, 2006
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  3. Alan Smithee

    dan.c.quinn Guest

    A pound of KHCA. Four one liter bottles should make
    for an easy fit. That stuff oxidizes quickly at working strength.
    Dilute at time of use only as much as needed. Bottles should
    be kept full. Perhaps do as I do and split to smaller full
    bottles as it is used. Considering the significant roll
    HCA plays in processing it needs to be treated
    with greater care. Keep your powder dry.
    If that pound were a homogeneous mixture you could spoon
    up a working strength just prior to use. Dan
    dan.c.quinn, May 24, 2006
  4. This package is for 1 gallon of stock solution, the 5
    gallon figure is for the working solution. Since the working
    solution has a very short lifetime its best to mix it as a
    stock solution and dilute it at the time of use.
    KHCA is mostly Sodium Sulfite, dessicated. The
    saturation at room temperature (70F) is about 270 grams per
    liter, the packaged product probably contains about 100
    grams per liter in the stock solution. However, there are
    other chemicals in it. You could probably mix it at double
    the stock concentration if its kept at around room
    As Sulfite oxidizes it becomes Sodium Sulfate. Sulfate
    will do no harm but is inferior to Sulfite as a wash aid.
    Richard Knoppow, May 25, 2006
  5. Alan Smithee

    Alan Smithee Guest

    As I turn...the package...over and read...the instructions...I now
    understand this...;^)
    (it's been two years since I mixed KHCA, I'd switched to Agfa...until
    What is/was in Agfa's 4&1 stock solution? It was much more concentrated at
    So maybe, if I'm lucky, I could have a 1.7 litre solution stock solution and
    then dilute 1:9 or there abouts. Too complicated.
    I'm thinking a heaping tablespoon (say, weight out 23.9g) in a litre for
    when I need to process film might be the way to go. Is it ok to just tightly
    reseal the packet as use as needed?
    Thanks Richard.
    Alan Smithee, May 26, 2006
  6. Alan Smithee spake thus:
    You might consider doing what I do, which is to simply use the main
    ingredient (sodium sulfite), in which case it's easy to do exactly what
    you proposed. I mix concentrate, but since the power is a single
    compound, you can measure it out dry as needed. I get mine from the
    local photo shop in resealable bottles from Lauder Chemical.

    You don't really need the other stuff that's in HCA.

    I hope that in a few years it [Wikipedia] will be so bloated that it
    will simply disintegrate, because I can't stand the thought that this
    thing might someday actually be used as a serious reference source.
    Because in its current form, it's not to be taken seriously at all.

    - Horst Prillinger (see
    David Nebenzahl, May 26, 2006
  7. Alan, I think you have a ONE gallon size package although the amount
    in it is a bit different from the bag I have in front of me now. Mine,
    bought only a couple of weeks ago, weighs 502 grams according to the
    label. It makes ONE gallon of stock solution which is then diluted 1
    part stock to 4 parts water to make the working solution. You do NOT
    have a package for 5 gallons of _stock_ solution, rather this will
    produce 5 gallons of working solution when diluted at time of use.
    I would not try mixing only part of the powder for anything because
    the components are not always evenly distributed. In any case you don't
    need to do this.
    According to Kodak literature the life of the stock solution in a
    capped, filled bottle is about 2 months. Kodak is usually pretty
    conservative in their life estimates. Working solution does not last
    that long. Its good for perhaps 8 to 12 hours in an open tray and
    perhaps a week in a tank with a lid on it.
    Since there is no sign of oxidation (like turning brown) one can't
    tell if the stuff is good or not without some chemical analysis, too
    much trouble to bother with.
    For those with the materials on hand and desire to make their own
    the approximate formula for KHCA is:
    Wash Aid Stock Solution
    Water 750.0 ml
    Sodium Sulfite, dessicated 100.0 grams
    Sodium Bisulfite 20.0 grams
    EDTA Tetra Sodium Salt 5.0 grams
    Sodium Citrate 5.0 grams
    Water to make 1.0 liter

    Dilute 1 part stock to 4 parts water for use
    Target pH is 7.0
    Richard Knoppow, May 26, 2006
  8. Alan Smithee

    Mike King Guest

    I suspect also that Kodak's figure is more for a one gallon bottle, if you
    sub-divide the stock solution into smaller quantities, use glass bottles
    completely filled and use either good caps or cheap caps with a layer of
    "Saran" wrap PVDC (polyvinylidene chloride), (the new Saran wrap is not as
    good they changed the formula to LDPE but still seals pretty good).
    Mike King, May 26, 2006
  9. Alan Smithee

    dan.c.quinn Guest

    OR, pour or spoon up an appropriate amount of sodium
    carbonate at time of use. Agfa's recommended hca for many
    years; washing soda. Abandon all that hassel associated with
    a multi-component perishable hca.
    Off and on I've been testing the wash water with potassium
    permanganate looking to optimise the all-post-fix routine including
    the hypo clearing step/steps. As has many times been pointed
    out the permanganate test is not a test of the paper itself. It is
    though a test for the end or near end point in so far washing
    will achieve.
    The way I look at it now, the paper, baryta, and gelatin are
    distantly akin to the resins used in water softeners. Thiosulfate
    and argentothiosulfate ions attach to the three print components.
    A study by Martin Reed showed the baryta layer to be the slow
    to come clean component. If it were just paper and gelatin
    the wash would be done much sooner.
    As for testing the paper, the HT-2 test is the at home test.
    It is not sensitive enough to indicate AT archival levels. BUT, if
    the HT-2 test shows Zero stain it does indicate that archival levels
    have been approached. That is my reading. Dan
    dan.c.quinn, May 28, 2006
  10. spake thus:
    What "hassle"? Only a hassle if one is a compulsive do-it-yourselfer
    like yourselfer, someone who evidently considers going into a photo shop
    and actually *buying chemicals* a sign of defeat or lack of manhood or
    something. Not a problem for the rest of us.

    I hope that in a few years it [Wikipedia] will be so bloated that it
    will simply disintegrate, because I can't stand the thought that this
    thing might someday actually be used as a serious reference source.
    Because in its current form, it's not to be taken seriously at all.

    - Horst Prillinger (see
    David Nebenzahl, May 29, 2006
  11. Alan Smithee

    Mike King Guest

    You missed the point, original poster already has a bag of HCA and wants to
    make it last but doesn't want to mix it to 5 gallons of working solution all
    at once. My suggestions had nothing to do with substitutions for HCA but
    with a way that OP could use the HCA he already has. When my stock of cheap
    HCA is gone (bought a few large bags on eBay a while back) I'll examine
    alternatives and will probably go to a dilute sodium sulfite solution, most
    of the other stuff in KHCA is to make it dissolve easier or keep longer in
    the jug.
    Mike King, May 29, 2006
  12. Alan Smithee

    dan.c.quinn Guest

    I did not miss the point. You missed my first post this thread.
    Your and my posts addressing the OP's question are in agreement.
    My second post this thread broadened the subject some.
    My point is why put up with a perishable hca when washing soda,
    Agfa's recommended hca, is so close at hand and at time of use no
    problem to mix; a one ingredient hca. I'm quite sure Agfa makes/made
    that recommendation on some sound basis.
    Quite frankly I can't understand why anybody bothers with a
    perishable hca. I'd have to see some hard data supporting any
    contention that some other hca does a better job then sodium
    carbonate. Then I'd weigh any short comings against it's non-
    perishable character. Likely we are in the dark. I've found
    no hard data and it likely does not exist. Dan
    dan.c.quinn, May 29, 2006
  13. Alan Smithee

    Lew Guest

    Hey Dan:
    Can you point me to some technical info about how much soda to use,
    times, final washes etc... Any difference between rc & fb?
    Lew, May 30, 2006
  14. Alan Smithee

    Lloyd Erlick Guest

    On 29 May 2006 15:46:09 -0700,

    May 30, 2006, from Lloyd Erlick,

    I agree, but with a slight additional point.

    Many water supplies are on the hard side, so
    a small amount of Calgon (sodium
    hexametaphosphate or potassium citrate) or
    EDTA before adding the carbonate helps a lot.
    Even here in Toronto, where the water is not
    particularly hard, I get a bit of cloudiness
    if I attempt to dissolve sodium carbonate in
    tap water (I assume it is calcium carbonate

    I'm quite sure Agfa makes/made

    Richard Knoppow has addressed this question
    directly. He said Agfa's recommendation was
    quite old, dating from a time before the use
    of sodium sulfite was known to be superior as
    a washaid. Carbonate is OK, sulfite is

    I tend to use both, whichever is at hand. I
    bought a large bag of sodium carbonate for a
    very attractive price some time ago, so I
    guess I just use it. For some reason I use
    sulfite for film and often carbonate for

    I wonder what Ansel Adams used before 1940??

    Lloyd Erlick Portraits, Toronto.
    telephone: 416-686-0326
    Lloyd Erlick, May 30, 2006
  15. Alan Smithee

    dan.c.quinn Guest

    From a quick Google search I found that Agfa recommends
    a 1% solution strength. I've not found much in specifics but a 20
    minute wash after a 3 minute Agfa alkali soak was mentioned.
    I've not yet found the article but recent research by Michael
    Maunder published in issue 31 of Ag+ Journal does look
    to be worth reading.
    I'm not very trusting of research results from the 40s and 50s.
    Emulsion incorporated hardeners are now days the norm. According
    to Mr. Knoppow, Kodak's sulfite based KHCA was compounded, at
    least in part, so as not to interfere with the acid fixers and their
    included hardener. The two are carried forward to a pre-rinse
    or to the hca. Today most fixers are without hardener. At
    least Troop's TF-3 and 4 are very alkaline.
    Users of a carbonate hca aren't so rare as I had thought. Agfa
    was still recommending such when they closed up shop. Dan
    dan.c.quinn, May 30, 2006
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