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  1. #11

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    Outstanding advice.

    I can kinda wrap my mind around the lower speed at larger batches, but luckily, I don't have to worry about that.

    Many thanks,

    BTW I just got my stiring plate tonight and decorated my counter and myself with warm water. There is now a glow in the dark marker that we won't be going above on the speed dial. Consequently, it appears to be rotating right around 300rpm Go figure, what a coincidence, or is that from experience as well?

  2. #12
    Photo Engineer's Avatar
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    Quote Originally Posted by Ian Grant View Post
    The secret is a small mixing chamber that the emulsion is pumped through, so the mixing is almost total in the chamber.

    Ian
    Ian;

    Regarding this and the other post you made, this was based on the Wey and Whiteley Patent, but was abandoned by Kodak in the late 80s for a better method. I have to tell you that even though Agfa and Ilford reportedly use what you mention, (and maybe Fuji) Kodak has devised a better (I think) method for handling this.

    PE

  3. #13
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    There are quite a few relevant patents but yes I guess USP 4399215 is a good starting point. Probably what's more important are the principles, no-one on APUG is going to to be making emulsions on a large enough scale to be too concerned with anything more than perhaps making a fairly simple mixing chamber.

    Ian

  4. #14
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    I've found that up to about 1/2 - 1 L a magnetic stirrer will work and over that volume a prop mixer. If you go much over 2 L you may need both a prop mixer and magnetic stirrer to keep the bottom moving well enough, but you need a very large bar.

    PE

  5. #15

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    Quote Originally Posted by Photo Engineer View Post
    NOTE TO KIRK - How do you think my lab coat got to looking the way it did?
    I thought you were just a slob... You did not get to see the holes in a lot of my shirts as I only wore ones that did ot have holes... :^)

  6. #16

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    So for making T-grains, where you have a lare excess of halide, does it make a difference? Ok, on a smaller scale at least. (I see the complicatios of pumping 100 liters in a minute and getting it to mix well.)

    Would not the large excess of halide allow you to not worry about where the nozzles are, as long as you have good mixing happening. The nozzle for the halide pretty much just needs to resupply the kettle with more halide, and the nozzle for the silver just needs to get good mixing into the surrounding solution.

  7. #17
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    Quote Originally Posted by Kirk Keyes View Post
    I thought you were just a slob... You did not get to see the holes in a lot of my shirts as I only wore ones that did ot have holes... :^)
    I am, but that is beside the point! I'm also clumsy.

    PE

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