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  1. #1
    drpsilver's Avatar
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    Ascorbic Acid Developer

    10 June 2012

    I "inherited" a bottle of ascorbic acid crystals, and thought now is the time to try an XTOL like developer. I am looking for developer formulations that work well with Tri-X and HP5+. Any suggestions?

    With this acquisition came a bottle of calcium ascorbate. Is this of any use in creating a developer?

    Regards,
    Darwin

  2. #2

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    Caffenol?

  3. #3
    Murray Kelly's Avatar
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    If you want to experiment with the calcium salt remember that carbonates and hydroxides will precipitate a cloud of insoluble calcium carbonate or hydroxide. Sulfites and borates are marginally soluble in water so that makes borax and sufites a poor choice and I have tried some with triethanolamine (TEA) as the alkali and that was apparently OK. No cloudiness. Also Calgon will make a good strong alkali solution and the calcium certainly shouldn't precipitate. That's what it's for, after all.

    You could just eat the stuff and keep healthy, too.
    Last edited by Murray Kelly; 06-11-2012 at 09:13 AM. Click to view previous post history.

  4. #4
    Athiril's Avatar
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    Photographically, how do the calcium salts differ from sodium and potassium? It's said potassium is more photographically active than sodium.

  5. #5

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    Calcium ascorbate is rather useless for developers since it will precipitate calcium sulfite from most developer formulations. Do you have a required primary developing agent like Phenidone, Dimezone, or Metol?
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  6. #6
    drpsilver's Avatar
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    11 June 2012

    Quote Originally Posted by Murray Kelly View Post
    If you want to experiment with the calcium salt remember that carbonates and hydroxides will precipitate a cloud of insoluble calcium carbonate or hydroxide.
    Murry:
    I had forgotten about the possibility of carbonate and hydroxide precipitation. Thanks for the "heads-up"

    Quote Originally Posted by Gerald C Koch
    Calcium ascorbate is rather useless for developers since it will precipitate calcium sulfite from most developer formulations. Do you have a required primary developing agent like Phenidone, Dimezone, or Metol?
    Gerald:
    I have a good supply of hydroquinone and metol.

    Thanks to all for your comments.

    Regards,
    Darwin

  7. #7
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    Quote Originally Posted by drpsilver View Post
    I had forgotten about the possibility of carbonate and hydroxide precipitation.
    Please note that this will not just be a possibility, but a big certainty. Most devs work only in caustic environments with pH levels above 8 or 9, and at these levels you will inevitably get Ca(OH)2 precipitation, regardless of which caustic you used to raise the pH.

    In theory, you could chelate away the calcium with EDTA, but the required amount of EDTA will be much more expensive than fresh ascorbic acid. If you still want to play with ascorbate developers, look at Mark Overton's (aka albada) recent thread. Lots of info to be found ...
    Trying to be the best of whatever I am, even if what I am is no good.

  8. #8

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    DS-2?
    A 5x concentrate keeps quite well in full sealed bottles.
    http://web.archive.org/web/200910051...ecommendations

  9. #9

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    If you don't mind me asking, what is Ascorbic Acid's purpose when used in a developer? I am interested to know I too have loads of crystals, but as a vitamin supplement, not the raw form of it.

  10. #10

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    Ascorbic acid is a developing agent that is used in place of hydroquinone because it is non-toxic. However the action of these two agents is quite different. When used alone ascorbic acid is very slow in its action and has a long induction period. For this reason it is most often used in a super-additive mixture with Metol or a Phenidone derivative.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

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