Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,553   Posts: 1,545,001   Online: 711
      
Results 1 to 7 of 7
  1. #1
    Mustafa Umut Sarac's Avatar
    Join Date
    Oct 2006
    Location
    İstanbul - Türkiye
    Shooter
    35mm RF
    Posts
    3,840
    Images
    108

    Pyro Paper Development

    I am reading on pyro with large time intervals. If I am not wrong , pyro effects emulsion with harder or softer zones. And harder the zones , it is more squeezed and lower profil.
    And I am thinking carbon printing. Do pyro development of papers reveals a carbon like higher lower profile map ?

    Thank you,

    Mustafa Umut Sarac
    Istanbul

  2. #2

    Join Date
    Jun 2008
    Location
    florida
    Shooter
    Medium Format
    Posts
    1,169
    Images
    2
    I can't answer your question but I use PMK Pyro for film and know it is quite toxic so I would hesitate to use it for paper since paper requires more handling and would be in a tray as opposed to a tank which would be closed or more confined (using film holders) for large format.

    http://www.jeffreyglasser.com/

  3. #3
    Ian Grant's Avatar
    Join Date
    Aug 2004
    Location
    West Midlands, UK, and Turkey
    Shooter
    Multi Format
    Posts
    16,273
    Images
    148
    I do use a Pyrocatechin tanning developer for prints, there's no relief effect, the emulsions are already well pre-hardened so you don't get the same swell effects.

    Also you probably need need a paper with no supercoat. Etch bleach works though, it's best with RC papers.

    Ian

  4. #4

    Join Date
    Mar 2005
    Shooter
    Multi Format
    Posts
    233
    I have used Donald Miller's Pyro Paper Developer, the updated version, found in the following link:

    http://www.apug.org/forums/forum37/2...developer.html

    Wonderful stuff, but one really needs a fume cabinet to use it. Sniffing volatile hydrocarbons isn't good for one's braims.

    K

  5. #5

    Join Date
    Jul 2010
    Location
    Southern USA
    Shooter
    Multi Format
    Posts
    3,840
    As a chemist I tell people to avoid pyrogallol due to its toxicity. This is a dangerous chemical and urge people to read the MSDS for it. The LDlo (lowest lethal dose) is only 28 mg per kilo of body weight which is much lower than other developing agents. it is rapidly absorbed through the skin and so protection like nitrile gloves are a must. In addition it is expensive and oxidizes rapidly in solution.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  6. #6
    Mustafa Umut Sarac's Avatar
    Join Date
    Oct 2006
    Location
    İstanbul - Türkiye
    Shooter
    35mm RF
    Posts
    3,840
    Images
    108
    Gerald,

    Thank you for your warning. What do you say about Pyrocatechin ?

    Thank you,
    Umut

  7. #7

    Join Date
    Jul 2010
    Location
    Southern USA
    Shooter
    Multi Format
    Posts
    3,840
    Catechol (the preferred chemical name) has about a third the toxicity of pyrogallol. Still it is considerably more dangerous than hydroquinone. This may be because the human body uses a group of chemicals known as catecholamines and catechol may interfere with their use. Catechol has a measureable vapor pressure at room temperature and the solid should be used with adequate ventilation. It has a distinctive phenolic odor reminiscent of the smell of an old-time drugstore.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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