first effort with fumed silica pre-coat

Discussion in 'Alternative Processes' started by TheFlyingCamera, May 24, 2012.

  1. TheFlyingCamera

    TheFlyingCamera Membership Council Council

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    Here is my first ever print made with a fumed silica pre-treat. I'm not sure if I'm getting the full benefit of it. The print was made with 20 drops Platinum, 20 drops Palladium, 4 drops 5% Ammonium Dichromate. 14x17 inch FP4+. Bergger COT320 paper. I'm getting some graininess and a little mottling which could be from the dichromate, and I think some of it is from (possibly) uneven coating of the fumed silica - see lower left corner. [​IMG]

    Apologies for the image quality - I had to do this with my cellphone as my home internet connection has been incredibly unstable the last couple days and I could not count on being able to upload from my Mac.
     
  2. Robert Hall

    Robert Hall Subscriber

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    Hey Scott,

    I found similar mottling when I didn't coat the the paper smoothly. Once I "worked" the emulsion in to the paper it cleared up. And I do see some streaks when I don't get the FS coating right.

    R
     
  3. TheFlyingCamera

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    Robert-

    how much volume should I apply? And how much 'working' should I do? I'm using the B&S prepared solution, not working from dry. I'm using foam rollers which I charge with the solution, then roll back and forth, much the way you're supposed to paint a wall (make the 'W' and then spread out). Is there a better technique/tool for applying it?
     
  4. Robert Hall

    Robert Hall Subscriber

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    Scott,

    Pardon the simi-flippant retort. Apply an even coat, what ever that coat needs to be. I do it dry, I like the dry, but thats me.

    The "working" for me on platine is to make sure the coating is not sitting on the top of the paper but has penetrated and gives the surface of the paper a suede kind of look.

    I apply it using a foam brush, I put enough on it to cover it well and knock off the leftovers by hitting the paper on its end. I get pretty good results, but it is certainly nothing I can rush. I coat the dry by brushing vertical all the way across then horizontally, then once more. I can see on the paper if it's even. Faint lines tell me if I have done it wrong where the brush edge has made contact too much.

    I have yet one more thing to try, however, and will do it this weekend. I want to do an acid soak to compare the results of acid bath to FS. I will, if I have time, will do some step wedges and sensitometry.

    Regardless, your print is awesome.

    R