Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 76,308   Posts: 1,681,740   Online: 1087
      
Page 3 of 3 FirstFirst 123
Results 21 to 28 of 28

Thread: yellow staining

  1. #21

    Join Date
    Nov 2006
    Shooter
    4x5 Format
    Posts
    5
    Hello, i have been thinking of posting a similar thread, and the issue of contamination is interesting. I work in a lab were we print mostly ilford warmtone. We have not, in the recent past had any problems with yellow staining when using sheet paper of any size, however, when we print murals we usually get yellow staining. This yellow is only along one edge, which is one end of a roll of mural paper, so I always chalked it up to manufacturing. As it is only in the boarder and only creeps in an inch or so it gets trimmed when mounted and we then forget about it. This past week I noticed it on two murals and went back and looked at the test strips which did not have the yellowing? We roll our murals thru long shallow trays that hold about a gallon of chemistry. Our stop bath is sprint, mixed double the strength our fixer is acidic (i think) NH5. We drain quickly and certainly not fully, but I wouldn't say we are any different with sheet paper. When fixing, we run prints thru a first fixer for 3minutes min, then a second fresh fix for 5. If we are making second or third prints the second print is going into a pretty fresh first fix (which was the second fix of the first print) and then a second fresh fix for 5. We have done a capacity check on the first fixer and it has plenty of life left for the second print not to mention that that print then gets a second fresh fix as well, but we still get staining. Any thoughts, questions or suggestions, would be great. If it is contamination or fogging, why would it only be on one edge? Thank you

  2. #22
    Nicholas Lindan's Avatar
    Join Date
    Sep 2006
    Location
    Cleveland, Ohio USA
    Shooter
    Multi Format
    Posts
    2,382
    Images
    4
    Quote Originally Posted by dancqu View Post
    STOPPING I believe is, for any practical purpose, equally quick acid or water.
    I think it appears that way because prints are almost always developed to completion.

    Water-bath development for contrast control is an example where water doesn't stop the development.

    As I understand it an acid stop halts development so the developer doesn't hit a silver-laden fix in an active state. The stop bath, of course, has no dissolved silver in it.

    Two bath developers like Diafine work on the principle that a lot of developing agent is carried in the emulsion and it takes a good bit of time for it to diffuse out.
    DARKROOM AUTOMATION
    f-Stop Timers - Enlarging Meters
    http://www.darkroomautomation.com/da-main.htm

  3. #23
    Nicholas Lindan's Avatar
    Join Date
    Sep 2006
    Location
    Cleveland, Ohio USA
    Shooter
    Multi Format
    Posts
    2,382
    Images
    4
    Quote Originally Posted by bjames View Post
    why would it only be on one edge? Thank you
    I have no idea - just throwing out a speculative question: is the roll ever held vertically so the liquid would migrate to the one edge?
    DARKROOM AUTOMATION
    f-Stop Timers - Enlarging Meters
    http://www.darkroomautomation.com/da-main.htm

  4. #24

    Join Date
    Jun 2004
    Location
    Portland, OR
    Shooter
    4x5 Format
    Posts
    3,268
    Quote Originally Posted by Sirius Glass View Post
    Acidic developers [Ansco 130] use water as a stop bath.
    Ansco 130 = acidic.

    What? With all that sodium carbonate in it, it most certainly will be basic, not acidic.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  5. #25

    Join Date
    Jun 2004
    Location
    Portland, OR
    Shooter
    4x5 Format
    Posts
    3,268
    Quote Originally Posted by MattKing View Post
    PE has posted on this a number of times.

    Fixers, including alkaline fixers, are designed assuming that acid stop-bath will be used.
    This needs repeated. PE has pointed out that TF-4 is buffered and can handle an acidic stop. And remember, you should let the print hang over the stop bath tray and let the excess stop on the surface of the print drain off the print.

    If you are really concerned about the TF-4, then try another fix, like Ilford Hypam or Kodak Rapid Fix and then you don't have to fret over such things.
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  6. #26

    Join Date
    Sep 2002
    Location
    Willamette Valley, Oregon
    Shooter
    Medium Format
    Posts
    3,684
    [QUOTES=Nicholas Lindan;849424]
    "I think it appears that way because prints are
    almost always developed to completion."

    Appearances count.

    The 10 and 30 second Kodak and Ilford quick dips are
    no quicker at washing out the developer than same time
    dips in H2O. The acid dips do though impart an overall
    acidic character to the paper making them compatible
    with the acid fix. More important in the days of the
    ubiquitous fix with hardener.

    "Water-bath development for contrast control is an
    example where water doesn't stop the development."

    Water bath technique calls for little or no agitation in
    the water bath. So the slow stop. Several cycles are
    usual; back and forth then back and forth then ... .

    "As I understand it an acid stop halts development so
    the developer doesn't hit a silver-laden fix in an
    active state."

    So too with a water stop. As the print developer is
    diluted it's ph is plummeting. Much diluted and with
    a ph nearing 7 the developer's activity nears zero.

    "Two bath developers like Diafine work on the
    principle that a lot of developing agent is carried
    in the emulsion and it takes a good bit of time
    for it to diffuse out."

    Once again little or no agitation. Also, the
    second B bath is quite alkaline. More so
    than than TF-4. Dan

  7. #27

    Join Date
    Nov 2006
    Shooter
    4x5 Format
    Posts
    5
    "I have no idea - just throwing out a speculative question: is the roll ever held vertically so the liquid would migrate to the one edge?"

    Thanks Nicholas, thats a great observation, yes we do tilt it to one end to drain. Im not sure what it means but if thats the edge which also fogs that would be very telling. I will have to pay attention to that specifically next week.

  8. #28

    Join Date
    Feb 2005
    Location
    Richmond, VA
    Shooter
    Multi Format
    Posts
    1,066
    About the acid stop with TF4 -
    The first time I used TF4, it was with Pyrocat HD and, I think, FP4, 2 1/4. I forgot about the recommended water stop and used a very weak acetic acid stop (something like a drop or two in 500cc water). I saw some strange artifacts in uniform areas of the negative (like sky areas) and called Formulary about it (I thought at the time that it was the Pyrocat). I was told in no uncertain terms that any acid in the stop was not good for the TF4. I replaced the fix, have adhered to the water only stop bath advice (I use a minute of running water in a tray for fiber prints - after a 15 second dip in a deep tray of water), and had no problems since.
    I hear what some of you experts are saying about the buffering of TF4, and recently, as described in a thread I put out a few weeks ago, I too, had some yellow edges in 16x20 Ilford MG IV VC, first time ever.
    What goes?

Page 3 of 3 FirstFirst 123


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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