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Thread: New Workshops

  1. #11
    billschwab's Avatar
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    Go for it PE!

  2. #12
    Photo Engineer's Avatar
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    Quote Originally Posted by Bob Carnie
    I would be very interested in a silver emulsion process to coat on rag paper for contact printing from enlarged negatives.
    I do coat on Bergger COT320, a cotton rag paper. It works out very nicely, but rag varies from batch to batch and therefore you would have to adjust the formula for the batch of paper. I have also coated on Strathmore, Cranes and Lanaquarelle.

    Basically it is a surfactant issue.

    Baryta paper varies as well, but for a different reason.

    I forgot to add that this summer and fall, I will be showing examples of coating contact paper on all of the above.

    PE

  3. #13
    L Gebhardt's Avatar
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    I am very interested and would try to attend all of them, but most likely would only be able to participate in one or maybe two this year.

    Would these be in Rochester, and about how long are you thinking?

  4. #14
    Photo Engineer's Avatar
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    Quote Originally Posted by L Gebhardt
    I am very interested and would try to attend all of them, but most likely would only be able to participate in one or maybe two this year.

    Would these be in Rochester, and about how long are you thinking?
    This summer, I am giving 2. One is at the Formulary in June, and the other is in NYC in Sept. Both are 1 week long and deal with emulsion making and coating.

    The others in the OP are for 2007.

    I would do custom tailored workshops in my home, if anyone was interested. These would be in Rochester at the persons convenience, but so far I have only done demos on the coating equipment.

    PE

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    Has there been any progress on putting together a coating kit(s)?
    Also, you mentioned a while back that there may be a non-sensitized baryta paper coming out. Is there any news on that.

    As for the workshops, I am interested in the coating one at PF or another one down the road.

    -Mike

  6. #16
    Photo Engineer's Avatar
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    Quote Originally Posted by reggie
    Has there been any progress on putting together a coating kit(s)?
    Also, you mentioned a while back that there may be a non-sensitized baryta paper coming out. Is there any news on that.

    As for the workshops, I am interested in the coating one at PF or another one down the road.

    -Mike
    The Kit is under construction and the bare essentials are already down on paper. These will be given to all participants in my workshops first. Parts of the kit are spread out over 2 rooms in our house right now.

    The first shipment of baryta paper is on its way to me. Five hundred sheets of 11x14 for coating tests and 150 sheets of 16x20 were shipped. I will keep everyone apprised, but remember that all formulas for every process will need to be reviesed for this paper, as there are barytas with barium sulfate and others with barium oxide. In addition, any impurities and surfactants change required formulations, so I have a LOT of work ahead of me on this seemingly simple problem. This paper is stabilized with phenol and Kodak used thymol, so I have to learn how this influences the final results. I only have experinece with the use of thymol. Surfactant changes further complicate this. This may change things more than I can predict. IDK. Fair enough?

    PE

  7. #17

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    Quote Originally Posted by Photo Engineer
    In addition, any impurities and surfactants change required formulations, so I have a LOT of work ahead of me on this seemingly simple problem. This paper is stabilized with phenol and Kodak used thymol, so I have to learn how this influences the final results. I only have experinece with the use of thymol. Surfactant changes further complicate this. This may change things more than I can predict. IDK. Fair enough?
    Are you sure about this?

    I've tested a LOT of surfactants and biocides before settling on the ones I use, but the difference in the biocides is minimal, as long as they are added to the finished emulsions. Both phenol and thymol are very old generation biocides and there are better ones that are safer to humans and environments, and inexpensively available because they are used in many industrial applications. I've tried all sorts of stuff but the choice of biocide is rather irrelevant to photographic property (except for certain quarternary ammonium salts), and the choice can be made by the biocide functionality alone.

    Surfactant is also a very important factor in making beautiful prints, but I see little need to change the surfactants added to the sizing, subbing, emulsion or overcoat layer to accomodate the differences among paper stocks. The surfactant choice is more strongly influenced by the coating speed, coating method, emulsion viscosity and the coating temperature.

    I don't know how fast you coat, but unless you are coating at the industrial speed, there are many surfactants that work very well.

    There is a larger issue that is not mentioned in your post. The binder system in modern emulsions incorporate nongelatin polymers in a small proportion (5 to 40%). The formulation of the binder system has a large impact on the quality of coated layers, such as swelling property, wet strength, brittleness, etc. If you are having problems in obtaining good coating, you should be looking at these issues together with the coating speed and temperature issues, because they are mutually dependent factors.

    Good luck

  8. #18

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    Methylparaben is what we used for polymers used in consumer products.
    art is about managing compromise

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    We use glutaraldehyde to keep the bugs from eating the starches and polymers.
    RL Foley

  10. #20
    Bruce Osgood's Avatar
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    Quote Originally Posted by Photo Engineer
    This summer, I am giving 2. One is at the Formulary in June, and the other is in NYC in Sept. Both are 1 week long and deal with emulsion making and coating.

    The others in the OP are for 2007.

    I would do custom tailored workshops in my home, if anyone was interested. These would be in Rochester at the persons convenience, but so far I have only done demos on the coating equipment.

    PE
    I would like to learn more about your Sept NYC workshop. Could you put me on a mailing list or however you spread information.

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