Establishing paper times with sodium thiosulphate fixer.

Discussion in 'B&W: Film, Paper, Chemistry' started by Sim2, Jul 8, 2012.

  1. Sim2

    Sim2 Subscriber

    Messages:
    457
    Joined:
    Nov 21, 2009
    Location:
    Wiltshire UK
    Shooter:
    Medium Format
    Hallo there,

    So I got the sodium thiosulphate fixer chemicals from our good friends at Silverprint, mixed up and all going well - but was wondering if there is a way to establish sufficient fixer times for fibre based paper? Film, I am thinking can run on twice the clearing time but paper, hmm not sure.

    Ralph's book details a method involving the use of a sulphide toner (which I don't have) - is there another way?

    All help/suggestions welcomed.

    Sim2.
     
  2. Gerald C Koch

    Gerald C Koch Member

    Messages:
    6,239
    Joined:
    Jul 12, 2010
    Location:
    Southern USA
    Shooter:
    Multi Format
    It's hard to overfix a print. Some say that leaving a print too long in a rapid fix bath (ammonium thiosulfate based) will cause bleaching. But in this case we are talking about hours not minutes. Residual silver tests are only useful if you intend to overuse your fixing bath. So for sodium thiosulfate fixer use a two bath system and fix for 5 minutes in each bath.