Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,929   Posts: 1,585,305   Online: 1098
      
Page 2 of 2 FirstFirst 12
Results 11 to 13 of 13
  1. #11

    Join Date
    Jun 2010
    Shooter
    Large Format
    Posts
    10
    Hey guys,
    even that I'm oficially at the vacation I couldn't resist to take a quick look at what you wrote . Denise - what you have written is actually very, very helpfull because i found a small detail that certainly had an influence on the gelatin and caused frilling on the edges and making the surface of the whole plate "fractured" (not sure if I'm using the word correctly - it's not smooth, looks like the surface has a lot of small grains or dots...). And the reason is the temperature changes! I always used developer at room temperature (so about 21-25 C), very cold running water for stopping wash and fixer also at room temperature. So there was actually 2 temperature changes. Now that i think about it, it surely was devastating to gelatin, weird fact is that it didn't came off completely.
    About chrome alum - a have a small stack and it's possible to get more. It's actually more difficult to get real photographic products (like Kodak Hardening Fixer and other un-typical thingies) than chemicals to make ones That's why I made the developper and fixer that Marc is advising (MQ developer and Hypo fixer).
    Anyway, I'll surelly peek here some time during my vacation (probably tomorrow :P), so feel free to comment and correct me.
    Thanks and Cheers!
    A.

  2. #12

    Join Date
    Aug 2005
    Location
    Earth
    Shooter
    Multi Format
    Posts
    1,560
    Quote Originally Posted by Asarnil View Post
    ...making the surface of the whole plate "fractured" (not sure if I'm using the word correctly - it's not smooth, looks like the surface has a lot of small grains or dots...). And the reason is the temperature changes! I always used developer at room temperature (so about 21-25 C), very cold running water for stopping wash and fixer also at room temperature. So there was actually 2 temperature changes. Now that i think about it, it surely was devastating to gelatin, weird fact is that it didn't came off completely.
    Sounds like you had some reticulation. Reticulaton isn't usually associated wth frilling or detachment; it often occurs without the others being present. One really should try to keep all solution temperatures close to each other. That should help the reticulation problem (if thats what it was) and hardening, as d. points out through the words of Baker, will help with detachment issuses.

  3. #13
    dwross's Avatar
    Join Date
    Feb 2004
    Location
    Oregon Coast
    Shooter
    Multi Format
    Posts
    850
    Reticulation is is caused by the uneven swelling and shrinking of gelatin pretty much constrained by its attachment to the plate. In addition to the physical appearance of wrinkles, silver grains can migrate from the valleys to the ridges, increasing the visual perception of texture or 'grain'.

    Frilling starts from the same causes as reticulation, but at the edges of the plate, where water can get under the emulsion and cause waves of swelled gelatin that separate from the glass. Big temperature swings is the major cause of both reticulation and frilling, but in addition, going from a strongly alkali developer to a really strong acid stop bath can do the same thing. The major cause of serious frilling, even if all the temps and pHs are balanced, is rough handling of the plates during processing. Try not to touch the edges any more than absolutely necessary and be as gentle as possible. Also, I remember reading a caution about too-warm hands. I always wear nitrile gloves and work at 65-68F, so I've never noticed a problem with that, but it makes sense. But, all in all, as you've noticed, gelatin emulsion is pretty amazingly tough stuff. You have to really abuse it to have significant problems.

Page 2 of 2 FirstFirst 12


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin