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  1. #11
    gainer's Avatar
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    The purpose of the sulfite in this developer can better be served by the ascorbate. I think you will be satisfied if you use 8.8 (0.05 M) grams of ascorbic acid in place of the sulfite and increase the borax to 100 grams. You may also use sodium or potassium ascorbate at 0.05 M. Whether you believe me well enough to try it is up to you. I think you will be surprised at the result if you do.
    Gadget Gainer

  2. #12
    hka
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    Quote Originally Posted by Tom Hoskinson View Post
    hka, Is it possible that you received CAS# 7757-82-6 instead of CAS # 7757-83-7.

    If so, you have SULFATE (acidic) in your developer instead of SULFITE (alkaline) in your developer. Needless to say, an acidic solution will not work with Metol.

    If you have litmus paper or a pH meter you can easily test this possibility.
    Tom,
    I checked the label and CAS # 7757-83-7 on it. That must be oke then.
    Maybe the lack of a pinch Sulfite before adding the Metol in the water is here the problem?
    I'am busy at the moment to make a new badge and come back later with the results.
    Thank you all for your time answering this question.
    harry

    Release, the best you can do...

  3. #13
    hka
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    Quote Originally Posted by gainer View Post
    The purpose of the sulfite in this developer can better be served by the ascorbate. I think you will be satisfied if you use 8.8 (0.05 M) grams of ascorbic acid in place of the sulfite and increase the borax to 100 grams. You may also use sodium or potassium ascorbate at 0.05 M. Whether you believe me well enough to try it is up to you. I think you will be surprised at the result if you do.
    Gainer,
    First of all I have the solve my problem at this stage. Later on I will give this opportunity a chance. Thanks anyway.
    harry

    Release, the best you can do...

  4. #14
    hka
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    As said I made a new badge D-76H and have done first a test with a piece of film to see if there is any activity...
    ...And, YES there is.
    Souped just a film in this new badge and the negatives came out very nice in tonality.
    Perhaps the pinch of sulfite may caused this problem. I used the same chems as yesterday. I patiently waited until each chemical where dissolved before adding the next one.
    Problem solved. Thanks.
    harry

    Release, the best you can do...

  5. #15
    gainer's Avatar
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    I thought I posted this last night. I'm glad it tidin't go through. I had a big boo boo.

    The sulfite in D-76H, besides serving as the alkali, is to keep oxidized Metol from slowing sown the reaction. Sodium or potassium ascorbate is more effective because it regenerates the oxidized Metol. If you substitute 8.8 grams of ascorbic acid or 10 grams of sodium ascorbate for the sodium sulfite and increase the borax to 25 grams, you may be quite happy with the results. You will wind up with 2.5 grams of Metol, 8.8 grams of ascorbic acid (0.05 M) and 25 grams of borax to make a liter of working solution.
    Gadget Gainer

  6. #16
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    Well, it did go through. You now can see that the boo-boo was in the amount of borax, which was 4 times too large for a liter. I think my machine is acting up. I would hate to think my brain was beginning to fail after only 80 years.
    Gadget Gainer

  7. #17
    jbj
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    the ratio of metol/Na Sulfite/borax seem appropriate for D76H based on my experience.

    I noticed that you listed the mw of your sulfite as the anhydrous. Over time due to its hygroscopic nature it will pick up water to form hydrates and you'll have to compensate by adding water to the mw/mol.

    i think monohydrate and heptahydrate are common stable hydrates of Na2SO3

    how does the sulfite look? free flowing granules, crystals, clumps?

    If hydrates are forming you'll have to increase the amount of Na2SO3 to compensate.

  8. #18

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    Quote Originally Posted by gainer View Post
    Sodium or potassium ascorbate is more effective
    because it regenerates the oxidized Metol.
    That may be the case for no more than sulfite
    or lower ph activated developers. Sulfite though
    will regenerate metol in carbonated developers. So
    use an ascorbate and activate with borax. Why not
    not go all the way and scrap the metol for phenidone?
    D-76-PAB? Dan

  9. #19
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    Quote Originally Posted by dancqu View Post
    That may be the case for no more than sulfite
    or lower ph activated developers. Sulfite though
    will regenerate metol in carbonated developers. So
    use an ascorbate and activate with borax. Why not
    not go all the way and scrap the metol for phenidone?
    D-76-PAB? Dan
    Where did you get that information about regeneration in carbonated developers?

    Anyway, the article on experiments with Metol and ascorbic acid goes on to describe other combinations including phenidone with ascorbic acid and borax. I have noticed very little difference in performance other than developing time. I'm not sure, if I shuffled strips of negatives from each combination, that I could tell which was which as long as CI was the same. In other words, whatever agent you have on hand will do about the same job where grain, resolution and gradations are concerned when you mix it with 0.05 M ascorbic acid and borax at or near saturation. You could start with 0.01 M concentration of the agent. That's about all you can dissolve of phenidone anyway. Metol is a little different in that 2 molecules of its base are combined with 1 molecule of sulfuric acid to form 1 molecule of Metol, so 1 molecule of Metol is worth 2 molecules of phenidone or p-aminophenol.

    I purposely stayed away from stronger alkali so as not to activate ascorbic acid and to get the buffering of the thick borax solution. A highly buffered self replenishing developing solution will have a high capacity. An advantage of phenidone may be its low sensitivity to bromide concentration. I haven't done all possible comparisons. I have in mind immersing a test strip in one of these developers, wiping off the excess, and hanging it in the dark to see if the amount of developer absorbed by the emulsion will be sufficient to develop it fully. Sort of a 2-bath without the second bath.

    You may argue on the besis of current thinking that this highly buffered developer will not produce very sharp negatives, but a test is worth a thousand arguments.
    Gadget Gainer

  10. #20
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    Quote Originally Posted by eumenius View Post
    Tom,
    Sulphite in that recipe is the only source of mild alkali, so if sodium sulphate is used instead of sulfite, the reason of non-working developer is found And if there was a sodium sulphide, or thiosulphate...
    *****
    No. The borax is also an alkali. There should be plenty of alkali with 100 grams sodium sulfite and 2 gms borax. But, as stated, if sodium sufAte were used, it would reduce alkalinity to below threshold needed for metol to work.

    John, Mount Vernon, Virginia USA

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