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  1. #1

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    Inconverntional darkroom setup part 2: a couple of chemistry questions

    I don't know if film is relevant, but it is efke 25 and arista EDU 100 and 400

    I bought D76, Dektol (which is D72, right? ) and kodak professional fixer.

    1. I need to know what concentration of 5% vinegar to use for the stopbath
    2. How to test the fixer for exhaustion. Some iodine salt method?
    3. Silver recovery, can I hook up iron/carbon electrodes to a battery charger and recover the silver? Or do I need a reference electrode and it's much more complicated.
    4. efke 25 and arista EDU. Are they tablet or cubic films?
    5. Am I missing anything obvious?

  2. #2

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    1) I use water for my stop bath. Save the vinegar for your salad. Just make sure the water stop is close to the temp of the dev.

    2) I use Edwal Hypo Check which is a solution of iodine "something" (don't have my notes with me). You can make this up with bulk chems and use a fomula in Anchell's "Darkroom Cookbook". Or, you can use the cut-off leader from a roll of 35mm. Put the leader in the fix and if it clears in about 1 minute, you're still good.

    3) Put a piece of steel wool (the funriture kind w/o the soap, not Brillo) in with your spent fixer. The wool will exchange stell for silver. Dump the "water", strain the rest and take the silver to your local scrap metal dealer. You can really get rich doing this

    4) The Efke and Arista films are cubic. Arista is made by Foma. Efke is its own company.

    5) Have fun!

  3. #3
    Photo Engineer's Avatar
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    Andrey;

    1. Stop is 2% acetic acid, so 1:1 dilution of vinegar will be close enough. Use white vinegar.
    2. Use 1% to 10% Potassium Iodide in water.
    3. Use steel wool
    4. Who cares, they are emulsions of silver halide in gelatin. Develop as intended and they work. They may not even be cubes, they may be amorphous. Unless someone does measurements with an electron microscope we can't really say for sure.
    5. Get out, take some pictures and test things out.

    PE

  4. #4

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    Thank you

  5. #5

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    Quote Originally Posted by Photo Engineer View Post
    Andrey;

    1. Stop is 2% acetic acid, so 1:1 dilution of vinegar will be close enough. Use white vinegar.
    And then I'll treat the 1:1 dilution as kodak stopbath, and dilute 1:63?

    The math doesn't add up. Even if the stuff kodak sells is glacial acetic acid, the directions are 1:63 for the working dilution. Giving less than 1.5% acetic acid solution.

    And it didn't seem like glacial AcOH.

    2. Use 1% to 10% Potassium Iodide in water.
    How do I make one? Where to get one?

    Thanks

  6. #6

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    For #1, I think PE means dilute the vinegar 1:1 to make a working solution.
    For #2, IMHO it's easier to buy a bottle of Edwal Hypo check, camera stores that still stock darkroom stuff will have it, or get it from the usual mailorder suppliers. You only need a drop or two at a time, so the 1.5 oz bottle will last a good while. If you want to go with the DIY method, there's Photographers Formulary, you can find their web site in the biz directory page. They probably have a pre-mixed equivalent too.

  7. #7
    Bob F.'s Avatar
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    Quote Originally Posted by Andrey View Post
    I don't know if film is relevant, but it is efke 25 and arista EDU 100 and 400

    I bought D76, Dektol (which is D72, right? ) and kodak professional fixer.
    1. I need to know what concentration of 5% vinegar to use for the stopbath
    2. How to test the fixer for exhaustion. Some iodine salt method?
    3. Silver recovery, can I hook up iron/carbon electrodes to a battery charger and recover the silver? Or do I need a reference electrode and it's much more complicated.
    4. efke 25 and arista EDU. Are they tablet or cubic films?
    5. Am I missing anything obvious?
    1) Use citric acid stop-bath - no pong (llfostop, amongst others).
    2) Do a clearing-time test every time you process. Dump it when clearing time doubles (I dump at +2/3) and/or use Tetenal fixer test strips (measures Ag & pH) if you can get them where you are.
    3) Never bothered - not enough fixer volume to be worthwhile.
    4) Don't know (don't care - use it if you like it).
    5) We all do, don't sweat it ...

    Have fun, Bob.

  8. #8
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    Quote Originally Posted by Andrey View Post
    And then I'll treat the 1:1 dilution as kodak stopbath, and dilute 1:63?

    The math doesn't add up. Even if the stuff kodak sells is glacial acetic acid, the directions are 1:63 for the working dilution. Giving less than 1.5% acetic acid solution.

    And it didn't seem like glacial AcOH.


    How do I make one? Where to get one?

    Thanks
    I wouldn't get hung up on the strength of the acetic acid, whether it's 1.5%, 2.0% or 2.5%. It will lose strength with use and you are dealing with dilution levels that won't harm the film or paper. As for potassium iodide, you can purchase it here...

    http://www.photoformulary.com/Deskto...ID=26&langID=0

    For a 10% solution, mix up and dissolve 10 grams of it in 100ml of water.
    "The secret to life is to keep your mind full and your bowels empty. Unfortunately, the converse is true for most people."

  9. #9

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    Quote Originally Posted by jim appleyard View Post
    Or, you can use the cut-off leader from a roll of 35mm. Put the leader in the fix and if it clears in about 1 minute, you're still good.
    Any fixed time for a leader-clearing test, like "1 minute," is bound to be wrong for some conditions. Fixers vary in speed, particularly between conventional (sodium thiosulfate) and rapid (ammonium thiosulfate) varieties and depending on dilution. Films also vary in clearing speed. Foma films are particularly quick to clear, in my experience. I'm not positive, but I suspect than Andrey's Kodak Professional Fixer is a slower sodium thiosulfate fixer, which could take over a minute to clear film even when it's fresh.

    Instead of using a fixed time, as Jim suggests, I recommend timing how long it takes to clear a particular brand and type of film in fresh fixer. When the clearing time for the film has doubled, the fixer is shot. Also, most fixer manufacturers have capacity notes printed on the packaging or on their Web sites, so you can consult that information.

    4) The Efke and Arista films are cubic. Arista is made by Foma. Efke is its own company.
    Arista is Freeestyle's house brand, and many different manufacturers have made or currently make "Arista" products. If the film really is Arista.EDU, as specified by Andrey, then it's actually made by Forte, not Foma. The Foma-made Arista product is sold as Arista.EDU Ultra (note the "Ultra"). Ilford and Agfa have also made Arista-branded films, but I doubt if Freestyle's got any of these left. (Even the Forte is probably mostly sold out by now.) Of all the Arista-brand films, to the best of my knowledge only the Dmax lines are/were T-grain films (they were rebadged Ilford Delta films that are no longer available under the Arista label).

    Efke is the brand name used by Fotokemika.

  10. #10

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    Quote Originally Posted by srs5694 View Post
    Any fixed time for a leader-clearing test, like "1 minute," is bound to be wrong for some conditions. Fixers vary in speed, parti
    Instead of using a fixed time, as Jim suggests, I recommend timing how long it takes to clear a particular brand and type of film in fresh fixer. When the clearing time for the film has doubled, the fixer is shot. Also, most fixer manufacturers have capacity notes printed on the packaging or on their Web sites, so you can consult that information.
    Thanks for pointing that out. I did know that, but why I didn't remember and pass it along is perplexing

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