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  1. #1

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    RA4 Enviroprint Starter formula ?

    Hello everebody, maybe someone knoe the enviroprint developer rtarter formula ?

  2. #2
    hka
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    See page 22 and on...
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    harry

    Release, the best you can do...

  3. #3

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    I know how to mix 1l. chemicals from concentrate. I ask starter formula because for 1 litre MP45 developer witch I use need 130 ml starter for working solution and it is cheaper to use homebrew starter but I don't know the formula of it. In that manual is nothing about starter formula

  4. #4
    Rudeofus's Avatar
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    Some base formulas for C-41, E-6 and RA-4 were published in patent literature, but AFAIK none of the commercialized concoctions were ever made public. Big labs mixed these bathes from scratch sometimes, using formulas given to them by manufactures, but to my best knowledge they are all bound by strict NDAs.
    Trying to be the best of whatever I am, even if what I am is no good.

  5. #5
    Analog Swede's Avatar
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    A formula?
    Potassium chloride, maybe a tiny tiny amount of potassium bromide, a carbonate buffer and perhaps some proprietary additives? The msds for the product reveals no details! Colorless, no smell, no VOC, completely miscible in water. No grim varnings about fires, explosions, poisoning or other hazards.

    I have checked a few patents about the amount of potassium chloride in a working developer. The intervall in them is 0.5 - 2.5g /liter.
    You can find a lot of useful (but also confusing) information in patents!

    Steven Keirstead has revealed a formula here: http://www.people.fas.harvard.edu/~k...technical.html

    If you calculate his addition of sodium chloride in a working solution you get 1.27g sodium chloride/liter.
    With Potassium chloride: 1.62g/liter

    Assuming that Keirstead's formula is correct (or at least close) and also assuming that the replenisher is totally void of chloride, a DIY starter at 130 ml per liter tank solution should contain 12g/liter potassium chloride.

    I have not tested this myself and cannot guarantee anything!

    Good luck!
    Jonas
    Last edited by Analog Swede; 02-22-2015 at 05:53 PM. Click to view previous post history. Reason: wrong developer...

  6. #6
    Rudeofus's Avatar
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    And few of us will test this formula, as Lithium Polystyrene Sulfonate is not one of these compounds that we have just sitting in our shelves. And nope, Sigma Aldrich doesn't seem to carry it anymore, either, not that they would have sold to an amateur. In the same fashion it may not be easy to source Etidronic Acid (aka Dequest 2010) in the USA.
    Trying to be the best of whatever I am, even if what I am is no good.

  7. #7
    mrred's Avatar
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    Wouldn't saving a bit from your old used batch, work as starter?
    Get it right in the camera, the first time... My flickr
    Peter Carter

  8. #8

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    I don't like to do that. I develop pictures in Jobo CPP proc and use fujifilm MP45 developer 50 ml to 1 picture 15 x 20 cm. This method gives best result but need to do fresh solution of developer any time when 1 litre ednds I doing new. I try to put used defeloper back in jobo bottle and replenish it as written in developer manual. But it doesn't work to small quantity of developer and developer become bad after 2 - 3 days if fresh developer is mixed with used developer. But fresh developer lives 2 -3 weeks. I ask about formula because starter coasts as 1 developer bottle and for 1 litre I need 130 ml starter

  9. #9
    Rudeofus's Avatar
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    So the problem appears to be that Fuji's RA4 starter is only sold in amounts seven times of what you need, and that its shelf life is shorter than the interval between two dev sessions.

    One possible way to solve your problem is starting with this recipe which you then replenish with your Fuji replenisher. RA4 is, after all, a standardized process, which means the starters should be very similar.
    Trying to be the best of whatever I am, even if what I am is no good.

  10. #10
    hka
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    1 Liter RA4 Developer Starter cost you about € 10,=?
    What I can recommend to do is fill 4 bottles of 250ml each with the fresh developer. Top off and use one of them for the first 5 excersises and so on...
    harry

    Release, the best you can do...



 

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