Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 69,908   Posts: 1,521,531   Online: 880
      
Page 1 of 3 123 LastLast
Results 1 to 10 of 22
  1. #1
    Mustafa Umut Sarac's Avatar
    Join Date
    Oct 2006
    Location
    İstanbul - Türkiye
    Shooter
    35mm RF
    Posts
    3,710
    Images
    108

    Uranium Nitrate Toning Recipe , Example and Experimenters mail

    When I saw this picture , I quite shocked. It was same tones which I got it from thorium rich Leitz Summitar.

    I quickly sent message to Rick and He sent me below message.

    I cannot tell you the exact formulation of my uranium toner, as I made adjustments on the fly with it. It consists of a mixture of acid buffered UO2(NO3)2 (pH=2 to 3) with a weak organic acid - I used either acetic, tartaric, succinic or oxalic acid, likely a combination of the later two. This solution is combined with a ferricyanide bleach to remove the metallic silver.

    It can be fixed after the toning, and the color becomes brighter and does not fade, or partially fixed to retain the blacks, or not toned at all to get earthy reddish browns. The color can also be attenuated by washing in a baking soda solution, but I found that by keeping the pH of the washing water between 6 and 6.5, the bright reds would be nicely stable after the prints dry.

    Sorry I cannot be more exact but I did not keep notes but rather mixed the solutions based on experimentation - this print, and the others like it are the result of many hours in the lab, mixing, toning, washing and drying.

    I obtained my uranium salt many years ago from JT Baker which no longer sells it. But uranyl nitrate is still used as an analytical reagent and googling it will lead you to distributors where you can buy it. I think it is several hundred dollars an ounce.

    The prints tone within 5 to 10 minutes, and I wash for twice that long. I do not know if positive film will work, you will need to experiment.



    He writes he uses below formula with adjusting after experimenting.


    Uranium Print Toner
    Uranium is a truly startling and dramatic toner that reliably produces a wide range of rusty-orange tones on almost any paper. Print flat and slightly light. Beware of overtoning as this causes the black to deteriorate. As with iron, a weak sodium carbonate solution will remove color and image. Wash in acidified water.

    Working Solution Chemical Amount Units
    Water 1000 ml
    Uranium Nitrate 8 g
    Oxalic Acid 4 g
    Potassium Ferricyanide 4 g


    REFERENCE
    Uranium Print Toner; Peter Hughes (Reichelt), Mastering Black-and-White Photography, p.49.


    HE NEVER DIPS HIS HAND TO THE SOLUTION , GLASS PROTECTION , HE USES RESPIRATOR , TWO LAYERS OF PROTECTIVE CLOTH , THICK VINYL GLOVES, NEVER TOUCHES THE PRINTS AND SECURE THEM IN SEALED GLASS CONTAINER


    Umut

    Istanbul

  2. #2
    Mustafa Umut Sarac's Avatar
    Join Date
    Oct 2006
    Location
    İstanbul - Türkiye
    Shooter
    35mm RF
    Posts
    3,710
    Images
    108
    http://101-365.com/photography/images/universalnude.jpg

    Here is the Rick's link.

    He is an member of APUG but no time but He will look at here.

    Umut

  3. #3
    Mustafa Umut Sarac's Avatar
    Join Date
    Oct 2006
    Location
    İstanbul - Türkiye
    Shooter
    35mm RF
    Posts
    3,710
    Images
    108
    Uranyl Nitrate, SPI-Chem™ Brand
    The finest uranyl nitrate available anywhere made entirely from depleted uranium for maximum safety.

    --------------------------------------------------------------------------------
    Uranyl Nitrate, Hexa-Hydrate
    N2O8U•6H2O
    CAS: #13520-83-7
    MW: 502.1
    APPEARANCE: Crystaline Solid
    RTECS: YR3850000

    Uranyl nitrate is usually used as an electron dense stain for transmission electron microscopy. However, it has also found application as 0.01% aqueous solution as a as a local catalyst in the polymerization of methacrylates. Reference: Hayat, M. A., Principles and Techniques of Electron Microscopy, 1970, Van Nostrand Reinhold, NY.

    Uranyl nitrate is soluble in water, ethanol, acetone, and ether, but not in benzene, toluene and chloroform. The aqueous solution can hold up to 56% of anhydrous salt at 25° C. Uranyl nitrate solutions are more stable than those of uranyl acetate solutions, but it is less efficient as a stain than the acetate. In tissue, it stabilizes nucleic acids and membranes when used prior to embedding. It is frequently used after sections are cut to "post stain" or further increase the contrast of membranes, etc., in sections. Uranyl salts, particularly acetate, are also used as negative stains for viruses and small cellular organelles in suspension. Reference: Hayat, M. A., Positive Staining for Electron Microscopy, 1975. Van Nostrand Reinhold, NY.

    Other electron dense uranyl based stains:
    SPI Supplies offers a reliable supply of other hard-to-find electron dense stains, including uranyl formate and uranyl acetate. Let us know what other needs you might have for any uranium based compounds, we are set up to produce just about anything in the way of uranium compounds, always with depleted uranium for safety and virtually no exposure hazards.

    Radioactivity statement:
    This material is made from depleted uranium, meaning that it is uranium from which the radioactive isotopes have been essentially removed.



    Restriction on shipments:
    Uranium-containing compounds, as well as uranium metal are subject to special restrictions from both the United States and other governments both for export from the USA as well as for importation into other countries.

    Shipping regulations:
    UN 2910
    Class 7

    To our customers outside the U.S., including Canada and Mexico – Please note that due to the special classification of this product as a radioactive material in excepted quantity, an additional surcharge of $120.00 has been assessed by the airline industry and will be added to the final shipping charges.

    SPI # Each In Stock
    5g 02546-AA $75.00 No
    25g 02546-AB $276.78 Yes

  4. #4
    holmburgers's Avatar
    Join Date
    Aug 2009
    Location
    Rochester NY (native KS)
    Shooter
    Multi Format
    Posts
    4,412
    Images
    2
    Wow, very interesting Umut. Thanks for sharing; I have been curious about uranium toning since it is mentioned a lot in the old texts.

    Talk about expensive... !
    If you are the big tree, we are the small axe

  5. #5
    ath
    ath is offline
    ath's Avatar
    Join Date
    Aug 2006
    Location
    Germany
    Shooter
    35mm
    Posts
    890
    Quote Originally Posted by holmburgers View Post
    Talk about expensive... !
    And REALLY dangerous!
    Regards,
    Andreas

  6. #6
    holmburgers's Avatar
    Join Date
    Aug 2009
    Location
    Rochester NY (native KS)
    Shooter
    Multi Format
    Posts
    4,412
    Images
    2
    What makes it so dangerous, since it's not radioactive? I assume it's highly toxic?
    If you are the big tree, we are the small axe

  7. #7
    kram's Avatar
    Join Date
    Jun 2006
    Shooter
    Multi Format
    Posts
    100
    Hi,
    Safety info on Uranium Nitrate

    http://msds.chem.ox.ac.uk/UR/uranium_nitrate.html

  8. #8
    holmburgers's Avatar
    Join Date
    Aug 2009
    Location
    Rochester NY (native KS)
    Shooter
    Multi Format
    Posts
    4,412
    Images
    2
    Here's an excellent write-up on Uranium prints and toning...

    http://www.blakeferris.com/mhtl/?p=379
    If you are the big tree, we are the small axe

  9. #9

    Join Date
    Sep 2008
    Shooter
    Medium Format
    Posts
    174
    Quote Originally Posted by holmburgers View Post
    Here's an excellent write-up on Uranium prints and toning...

    http://www.blakeferris.com/mhtl/?p=379
    That is a very interesting read. My favorite bit:

    "The Mercuro-Uranotype had a brief life in the later 19th century; another printing out process, it employed a sensitizer made from a 10:1 mixture of saturated uranium chloride and mercuric chloride solutions. It became obsolete by the end of the century, perhaps because its purveyors all poisoned themselves with the extremely toxic sensitizer formula."

  10. #10
    ath
    ath is offline
    ath's Avatar
    Join Date
    Aug 2006
    Location
    Germany
    Shooter
    35mm
    Posts
    890
    Here's the parallel tread on RFF where Chris101 goes into detail how he handles the stuff and why.
    Regards,
    Andreas

Page 1 of 3 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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