Adding photoflo to silver nitrate

Discussion in 'Alternative Processes' started by ronlamarsh, Sep 8, 2009.

  1. ronlamarsh

    ronlamarsh Member

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    I have determined I need a surfactant to get my paper properly coated. Will photoflo work? Also does one add it to my total supply of sensitizer or to just what I intend to put on the paper. Also will It help to add it to my salt solution?
    I ask this because I am having a hard time getting my slat prints to come out well. Right now they come out real blotchy in spots and a very light mauve in others. So I figured my problem is that either the sensitizer, the salt solution or both are not penetrating or sloughing off during coating. I suspect my salt is soulghing off when I coat with the sensitizer as the edges of the coating outside of the negative are a very red brown and grainy yet the areas that come out right and a very cool brown also I just checked some salted paper and noticed that the surface feels gritty! Any thoughts?
     
  2. jeffzeitlin

    jeffzeitlin Subscriber

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    I add 2 drops of Tween 20 to my sensitizer.
     
  3. phritz phantom

    phritz phantom Member

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    related question:
    which surfactants are recommended for silver nitrate processes and/or cyano?
    is everything called "wetting agent" equally suitable? i have some some "mirasol" (from tetenal) on hand. sorry, the bottle doesn't really list any ingredients.
     
  4. Loris Medici

    Loris Medici Member

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    I don't think you'd normally need a surfactant with salted paper. Both of the solutions should be readily absorbed in paper without any problems. I think your problem is:
    a. uneven sensitizing/improper technique
    or
    b. paper incompatibility...

    Do you tray sensitize or brush sensitize? Which paper do you use? Do you size the paper/how? Have you tried some other papers?

    Regards,
    Loris.

     
  5. ronlamarsh

    ronlamarsh Member

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    Coating troubles

    Lorris thanks,

    I am usings arches platine, I first tried it just plain without sizing as it was intended for platinum and other alt processes. Then I also tried sizing with gelatin and the salt mixed in using the immersion method. Neither one made much of a difference.
    Coating with silver I have used rod and brush and both make little difference except the brush seems better than the rod. I just made another print on gelatin sized paper(arches platine again) and coated with a rod but really slathered it on(4ml for a 5x7) I had all kinds of puddles but kept pushing it around until most were gone then pushed the excess off the edge. It has come out the best so far but still uneven. I noticed that the print is much better in the area's where I concentrated on moving the rod very slowly, maybe 20 sec to cover a 5x7 and with a goodly amount of pressure.
    Any suggestions? Should I use a brush? using an excess of sensitizer partially cured the problem but I think I have a technique problem.
     
  6. Loris Medici

    Loris Medici Member

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    Try to do it right w/o sizing first. Sizing is an extra complication and may not be needed with some papers. First see if you're able to get smooth tonality then you'll go for contrast and sharpness (by sizing) if you need it... AFAIK, Arches Platine has a fairly stong size already.

    BTW, what was the strength of sizing? Gritty surface hints too strong sizing solution for the bloom of your gelatin. Also, tray sizing is a mess; if you absolutely need to size then do it with a foam brush, working the size in paper thorougly, keeping the gelatin/salt solution in a vessel that stays on a hot plate meanwhile.

    Is your environment too dry? Excessively dry (< 40% RH) environment may cause uneven sensitizing. Try to raise the RH and/or use an ultrasonic humidifier to humidify the paper (by keeping it in front of the nozzle).

    4-5ml per 5x7 seems ultra excessive to me. I'd use less then 1 ml for that size if coating with a rod.
     
    Last edited by a moderator: Sep 10, 2009
  7. Jim Noel

    Jim Noel Member

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    IT SOUNDS MORE LIKE A PAPER PROBLEM. SALT PRINTS WERE ORIGINALLY DONE ON VERY LIGHT, LESS THAN 20 LB, PAPER SIZED WITH GELATIN. I USE 100 % cOTTON RAG STATIONERY. Sizing with gelatin gives me excellent prints. There is no need to add surfactant.
     
  8. ronlamarsh

    ronlamarsh Member

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    Results

    Thanks to all for their suggestions I know it is difficult as hell to remotely diagnose a problem.
    After much thinking and re-examination of my failures I started over:mixed new salt solution with distilled water: used unsized arches platine. Made 2 prints on brush sensitized and the other coated with a rod. The brush sensitized paper I used 2ml and brushed VERY LITELY unit a smooth coating was achieved. With the rod I began with 1ml and made about four passes with the rod, waited about 2 min and did the same with another 1ml.
    The results were very gratifying: the brush coated image was very smooth and all around excellent now all I need is the proper negative. The rod coated image was too intense with a very strong red/brown I assume I used too much sensitizer(2ml) but the image itself was smooth and well coated.
    The bottom line I think I may have not used distilled water for the salt solution. :D