Salt prints bleaching when fixed

Discussion in 'Alternative Processes' started by ColinRH, Mar 10, 2011.

  1. ColinRH

    ColinRH Subscriber

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    I have been doing salts for a little while and getting some good results - see my small gallery. The problem is that I am having to print the image so heavy because when I fix it, the image is bleached away quite severely. I just wondered whether anyone might have a suggestion to overcome that problem. I have tried sodium bicarbonate in the hypo without success.
     
  2. Vlad Soare

    Vlad Soare Member

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    Do you by any chance use normal strength fixer? That will indeed bleach the image severely. I've experienced it with vandyke prints. I now use 1.5% (give or take) plain sodium thiosulfate solution (one tablespoon per liter). Problem solved.
    I don't know about salt prints, but since they're also made of colloidal silver I suppose they can't be too different.
     
    Last edited by a moderator: Mar 11, 2011
  3. UKJohn

    UKJohn Subscriber

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    Hi Colin,

    I use two fix baths each for 3 mins and based on the following recipe:

    700ml warm water (about 30c)
    40g Sodium Thiosulphate (to give 4% solution)
    20g Sodium carbonate
    make up to 1000ml.

    I find this reduces the amount of bleaching significantly.

    I use a 2% salt wash (1 min) straight after exposure which does bleach the image back somewhat, then tone prior to fixing which I find helps to reduce the amount of bleaching that takes place during the fixing stage.

    I hope this helps.

    John
     
  4. ColinRH

    ColinRH Subscriber

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    I use 10% hypo and fix for 5 minutes. I came to this conclusion initially by using Wynn White's recipe. I then wondered if I was using too much hypo and did some test by fixing pieces of paper which had only been sensitised and then washed and fixed. No exposure to any light. I used 5% - 7 1/2% - 10% strengths fixing for times from 2 - 6 minutes minutes for each strength. After washing and drying they were left to normal daylight exposure and ALL except the 10% 4minute and 6 minute exposures fogged to a greater or lesser extent. That confirmed in my mind I had got the strength correct. I finally decided on 5 minutes to be sure. It may be that I am not aware of some other effect on the solutions but thats the way I see it.
    I am at present carrying out further trials with sod. bicarbonate in the hypo. We'll see!
    Thank you for your input. colin
     
  5. juan

    juan Subscriber

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    Agree on the less strong fixer - I also use 10%. Also, you can tone with gold (as I use) or selenium before fixing. That greatly reduces the bleaching.
    juan
     
  6. semeuse

    semeuse Member

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    I agree with the weaker dilutions. I also add cadmium bromide to the salting solution - it gives me faster exposure times and a barely noticeable tone warming.
     
  7. ColinRH

    ColinRH Subscriber

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    I am pleased that others have come to the same conlcusion concerning the weaker hypo solutions.
    Juan : the selenium route seems a good way for me to try particularly as I have some selenium toner at present. What are your dilutions and timing? I guess you give a wash after the exposure - in to the toner - and then wash as normal?
     
  8. juan

    juan Subscriber

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    I don't remember the selenium dilution, but it should be available if you search - maybe on unblinking eye. Yes, give the normal wash after exposure, then into the toner, then into the fix.
    juan