Defcat 2

Discussion in 'B&W: Film, Paper, Chemistry' started by c6h6o3, Mar 14, 2005.

  1. c6h6o3

    c6h6o3 Member

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    What does the stain look like?
     
  2. Ole

    Ole Moderator Staff Member Moderator

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    Looks like I'll have to buy some propylene glycol... :smile:
     
  3. jim appleyard

    jim appleyard Member

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    Thanks Jay. I've got several tons of chemisrty to go thru, including a bottle of Rodinal with the rubber stopper, but when I run out, I look forward to trying this one as well as the Rapid.
     
  4. Ole

    Ole Moderator Staff Member Moderator

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    In my experience pyrocatechin does rather well in acidic solution, and deteriorates rapidly in alkali - q.v. what the Pextral solutions look like after use. So I'll give it a go when I get home.
     
  5. john_s

    john_s Subscriber

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    I kept a quote from a post by Sandy from some time ago. It's a 2-bath catechol (a.k.a. pyrocatechol, catechin, pyrocatechin) formula.

    I haven't used it. Has anyone given it a try?

    This was in the context of people wondering what is/was in Dixactol, Barry Thornton's 2-bath proprietary catechol formula.

    "Barrry Thornton published an article in Professional Photographer several years
    ago which included a split-development formula based on pyrocatechin that
    he claimed to be stronger staining than PMK, with a non-actinic brown
    stain (neutral efffect on VC papers).

    Bath A concentrate
    Pyrocatechin 10g
    Sodium sulphite 2g
    Potassium bromide 0.5g
    Water to 100ml


    Bath B concentrate
    Potassium hydroxide 10g
    Potassium bromide 0.5g
    Water to 100ml

    Working solutions of bath A and bath B are mixed 1:14 with water. He
    recommends 4 minute development in each bath at 21 C, with agitation once
    every 30 seconds in bath A, once every minute in bath B. No rinse between
    baths."
     
  6. Kirk Keyes

    Kirk Keyes Member

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    You are saying that the function of sodium sulfite is the same as ascorbic acid? ?