gelatin hardener

Discussion in 'Silver Gelatin Based Emulsion Making & Coating' started by kevin klein, Jan 23, 2007.

  1. kevin klein

    kevin klein Member

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    When developing my experimental gelatin ambrotypes in the developer (premixed) containing Ammonium Thiocyanate, the gelatin swells and starts to disolve. But using freshly made developer will not have that efect.

    Can a hardener be added in to the developer or shuld the plate be put in a solution of hardener first?
     
  2. Photo Engineer

    Photo Engineer Subscriber

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    Ammonium thiocyanate is a powerful reticulating agent, particularly with poorly hardened films. There is not much you can do unless you do it in the coating itself with chrome alum or glyoxal.

    PE
     
  3. kevin klein

    kevin klein Member

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    other cyanates

    My next experiment is to use sodium and potassium thyosyanate in the developer to see if it will be any better.
     
  4. Photo Engineer

    Photo Engineer Subscriber

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    No, it probably will not be better. Thiocyanate is most likely what is causing the problem.

    PE
     
  5. Photo Engineer

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    I've done some thinking on this and I wonder if pig gel might help you. You are probably using bone gelatin, but pig gelatin is subject to less swell at alkaline pH and may not reticulate or blister as much with thiocyanate. IDK for sure if it would help, but you might give it a try.

    PE