PC-TEA variants?

Discussion in 'B&W: Film, Paper, Chemistry' started by Lachlan Young, May 18, 2006.

  1. Lachlan Young

    Lachlan Young Member

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    I have gathered together all the required ingredients to make 100ml of PC-TEA but I have two questions. There appear to be two different formulae for PC-TEA - one with 10g Ascorbic Acid the other with 9g - which is correct?
    Secondly, what would be suitable starting times when diluted 1+50?

    All help much appreciated,

    Lachlan
     
  2. Jordan

    Jordan Member

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    I don't think either is necessarily "correct". I believe 10 g ascorbic acid was the earlier version, identical to the older PC-Glycol formula. The pH of this working solution will be lower (i.e. longer developing times -- but the difference may be slight) than one made with 9 g ascorbic acid.

    I use the 10g version. For 400-speed films at box speed, about 8-9 min at 22C seems to be a good starting point.