Metol and Sodium Sulfite

Discussion in 'B&W: Film, Paper, Chemistry' started by Saganich, Aug 16, 2011.

  1. Saganich

    Saganich Subscriber

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    I mixed a stock of D23 variant (5g Metol and 50g Sodium Sulfite) as a first bath for a two bath process. Since I'm experimenting I wanted to increase the Metol to 8g and wondered if adding more Metol will work since the mixing order, if I recall correctly, is significant in this case. If so is there a way around, such as first mixing a pinch of SS and the extra metol in 100ml then adding to the stock. Or shall I resign myself to mixing a new stock?
    Thanks,
    Chris S
     
  2. el wacho

    el wacho Member

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    if you have problems mixing the extra 3g of metol you can mix up an extra 50ml with a pinch of sod. sulfite and add it to your 500ml. remember to account for the extra 50ml your A solution which will be 550ml. i've experimented with metol/sod. sulfite A baths and have found that there is a big difference between 6.25g/Litre and 7.5g/Litre solutions - the latter being more sensitive to temperature variations as an A bath ( B bath being 20g/Litre of sod. carbonate ). i imagine 8g of metol to be quite active and require repeatable temp control. good luck with your experiment and let us know what happens. i'll be very interested.
     
  3. Gerald C Koch

    Gerald C Koch Member

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    It's not that Metol is insoluble in sulfite solutions but it is slow to dissolve. Heat your solution to 125 F and then add the extra 3 grams. You may have to stir quit a bit but it will eventuaally go into solution.
     
  4. Saganich

    Saganich Subscriber

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    Thanks, its good to hear that adding more Metol won't ruin the stock. Thanks for the heads-up about the temperature sensitivity. What I'm doing is a variation on Vestal Split D76, without HQ. 5g Metol, 50g Sod Sulfite bath 1 and 5 grams Borax, 50 g sod sulfite bath 2. I dubbed it D550. The first experiment I agitated continuously for 6 minutes each. Great highlight contraction about N-2 with nice highlight detail in the shadows for TriX@320. Lost about one-half stop film speed. So for 6 min split TriX would have been happier at 200 or 250.

    I want to increase the activity so I can 1) agitate normally, 2) get an N dev time at a 6/6-10 minutes, and 3) get better zone I density at ASA 320. Basically achieve what I was getting for straight D23 at 12 minutes triX@320 in a two bath process with borax and see how it compares from a image and utility perspective.
    Chris
     
    Last edited by a moderator: Aug 16, 2011
  5. el wacho

    el wacho Member

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    may i direct you Barry Thornton's work on this kind of developer in 'Edge of Darkness'. he pinned the optimum level of metol at 6.5g/Litre for the two bath process. some food for thought as you experiment. cheers.
     
  6. Saganich

    Saganich Subscriber

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    Thanks, I worked with Thorton's version for a few months. The activity was low as well, great for n-3 and n-2 development. The higher alkaline sodium metaborate may be a better substitute for borax in low action development. I agitated the Thorton D23 normally Decent ASA, 320 for TriX. I'm convinced that triX just isn't absorbing as much developer and needs more activity to get those great midtone/highlight separation I know is possible.

    One observation regarding splitting 100g of Sodium Sulfite between A and B bath is the solvent action isn't as pronounced and looks more like Thorton's variation with 85g/liter sodium sulfite rather then straight D23 with 100g/l. I expected the solvent action to be the same as using 100g/l soduim sulfite as in D23 for the same development time. Splitting definitely affected the Sod sulfite's solvent effect on the grain in a way that is less flattering

    Chris.
     
  7. el wacho

    el wacho Member

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    i used to use metaborate as a B bath but concluded after testing that, unless i specifically wanted the fine grain look of metol 85g/L sod metaborate 12g/L, i prefered the look of sod carbonate 20g/L - total development in bath B. mid tones, to my eye, separate well ( by printing at grade 3 - 3.5 ) without the highlight being too problematic ( highlight gradiation is also maintained ).

    what splitting has done is lowered the sulfite content, improving perceived sharpness. i never understood the benefit of having the extra 50g thrown in bath B. perhaps someone will chime in. if you like the look of sod sulfite 100g/L ( which suggests to me you want smooth tones at somewhat the expense of sharpness then pursuing max absorption at bath A and local development in bath B may be counter to that look?