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Thread: Defcat 2

  1. #1
    c6h6o3's Avatar
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    Quote Originally Posted by jdef
    TMY

    Jay
    What does the stain look like?

  2. #2
    Ole
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    Looks like I'll have to buy some propylene glycol...
    -- Ole Tjugen, Luddite Elitist
    Norway

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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.

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    Ole
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    Quote Originally Posted by jdef
    You can make the developer up without the glycol, but I don't know how long the concentrate will last in an aqueous solution, even without the alkali.
    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.
    -- Ole Tjugen, Luddite Elitist
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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. #6

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    Quote Originally Posted by jdef
    The ratio of pyrocatechin to sodium sulfite in Thornton's developer is the same as the ratio of pyrocatechin to ascorbic acid in Defcat 2, so maybe a similar dilution of Defcat 2 would produce similar results?
    You are saying that the function of sodium sulfite is the same as ascorbic acid? ?



 

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