benzatriazole and HC-110

Discussion in 'B&W: Film, Paper, Chemistry' started by icmartin, Oct 23, 2004.

  1. icmartin

    icmartin Member

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    How much benzatriazole powder should I add to my HC 110? I used to know but haven't done it in a long time. I did it to get an additional stop of shadow detail. I use working solution B and HP5+. Should I add the benzatriazole to the stock solution or the working solution?
    Thanks!
    -IC Martin (Ian Martin, the new one, not the Ian Martin who joined the formum before me...)
     
  2. MikeK

    MikeK Member

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    Never heard of using Benzo to gain an extra stop of speed before, I would have thought it would have the opposite effect. A small amount of benzo will stop a developer dead in its tracks. The main use of benzo is an anti-foggant like Potassium bromide.

    Are you sure you really mean sodium sulfite?

    - Mike
     
  3. Poco

    Poco Member

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    Mike,

    I regularly add potassium bromide to D76 to suppress base/fog and thereby get better shadow contrast. I guess it "increases speed" to the extent it makes the lowest densities printable by separating them from base/fog .
     
  4. Bruce Osgood

    Bruce Osgood Membership Council Council

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    Ian Martin The Younger,
    I've not used any form of HC 110 but do regularly us a variant of Dektol (D-73) with an additional 10 mL of a 2% solution of Benzotriazol. I have not altered the amount of Potassium Bromide I usually use. I add the Benzo as the last additive in preparing the stock solution and dilute a portion of the Stock to 1+2 as a Working solution.

    As Benzotriazole is difficult to dissolve in water I use Isopropyl Alcohol (99% pure) and find no problem in its' dissolving.

    I do feel the 'de-fogging' of shadows to allow greater definition but I wouldn't say there is a full stop difference.
     
  5. icmartin

    icmartin Member

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    more info

    When I was in college (UC Davis) I had an excellent professor who suggested adding a 1% benzatriazole solution to HC-110 for processing my HP5+. I haven't done this in a long time and I can't remember how I was supposed to do this... My best guess was that I was supposed to do this to the stock solution and go from there. I do remember excellent shadow detail from doing this. How does this sound? I take benzatriazole powder and add it to the stock solution so that it's 1% by weight. Does that make sense? Is there a better way to go from a dry powder to a liquid by volume? I would then use solution B. I appreciate the feedback!
     
  6. Dr.Kollig

    Dr.Kollig Member

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    Certain formulas list a few ml of 1% Benzotriazole solution, like Crawley FX-37, it says 5 ml for the stock which is diluted 1:3-1:5, giving a total of 0.8-1.25 ml Benz. solution per litre working solution.
    So I would aim 1-2 ml of a 1% Benz. solution per litre working solution.

    I would add the Benz. solution when you prepare the working solution and not to the stock solution of HC 110.

    We rather use 1% Benz.-solution when working with papers to change the tone towards cold or to "repair" fogged papers. We use 2-5 ml per litre of paper developer and adjust from there.

    Wolfram