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  1. #11
    Ole
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    Quote Originally Posted by John Bartley
    The second bath for me is sodium metaborate, which I think Ole has identified as Borax and which I seem to remember also being called "washing soda"?
    I hope I haven't done that - you list three very different alkalis there!

    Metaborate can be made by mixing borax and lye at a very exact ratio, and is more alkaline than borax. "Washing soda" I believe is sodium carbonate, which is even more alkaline.

    All these alkalis can be used as bath "B", however. They will also give different results!
    -- Ole Tjugen, Luddite Elitist
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  2. #12
    Donald Qualls's Avatar
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    Correct, Ole -- borax is sodium tetraborate (usually the decahydrate, crystalline form is what's available). Sodium metaborate has been sold commercially as Kodalk, or Kodak Balance Alkali, and it somewhat self-buffering as well as being slightly more alkaline than borax. Washing soda is sodium carbonate, some places in Europe it's referred to as "household soda" and its primary use is for alkalizing laundry water to improve the action of detergents; it's more alkaline yet than either borax or sodium metaborate. Since, at least with metol, increasing alkalinity results in increasing activity, you can tailor how much development takes place in shadows in the second bath with a two-bath D-23 process by using one or another of these chemicals -- borax will give less increase to the shadows by the time the highlights exhaust, metaborate somewhat more, and carbonate the most (of these three).

    FWIW, a true "divided" development would have little or no alkali in the first bath -- D-23 made with, say, 20 g of sulfite, just enough for preservative function, instead of 100 g would qualify -- and the effect of that first bath is solely to saturate the emulsion with unactivated developer; very little or no development takes place even with a long soak (a few divided developers contain strong restrainers in Bath A to prevent premature development from taking place). The second bath then activates the developing agent carried over in the emulsion (and in the case of a reduced sulfite D-23 should contain the remainder of the sulfite that would otherwise have gone in the undivided developer as well as an alkali chosen to provide the effect desired). Such a true two-bath developer is very insensitive to time and temperature as long as minimums are observed -- temperature above about 65 F and time of at least three minutes in each bath is typical for two-bath "divided" developers -- and usually provides moderate to strong compensation due to local exhaustion in highlights.

    Another advantage of a true divided developer is that Bath A can be reused indefinitely and optionally replenished by simply replacing lost volume with fresh solution, while Bath B can be kept fresh by discarding and replacing an equal amount to that required to top up Bath A (the classic method of replenishing Diafine) -- or both baths can be reused until the volume loss on Bath A is excessive, then both discarded and replaced with fresh solution. With some divided developers, one needs to also watch for oxidation of the developing agent -- Divided D-76 is one where brownish discoloration of Bath A may be cause for replacement, just as it would be with stock solution of conventional D-76. Discoloration of Bath B is generally unimportant with true divided developers.

    If you're mixing your own D-23 anyway, it might be worth trying it as a true divided developer -- you'll probably find you like it, and you can still tailor the action by using Bath B made with sulfite only, borax, metaborate, or carbonate, in order of increasing levels of shadow development for a constant highlight density (given constant exposure, of course) (though the sulfite-only Bath B might require additional time in that bath compared to the others).

  3. #13
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    Quote Originally Posted by John Bartley
    This would be an opinion, NOT advice. I have only been at this for about 8 months, so very much the beginner. I like things simple, so I bought the raw chemicals and mix my own D23. I use it divided and develop both film and paper in it. It's simple, easy to mix, easy to use and cheap enough. My next self mixes are going to be stop and fix so that I can reduce darkroom odour.

    cheers

    Check out my article in the "Chemistry Recipes" section on Divided Paper Developers. In addition to formulas, it gives a description of the technique and its advantages.

    If you like to play around a bit, I experimented for awhile with a developer I called D-23C. I reduced the amount of sulfite considerably and added a bit of ascorbic acid which is also superadditive with Metol. Worked well. But later, I became more attached to the Phenidone/Vitamin C formulas that Pat Gainer worked on, and that he and I and others have given formulas for in other posts on this forum. I rarely use Metol anymore or Sulfite (one of the more expensive chemicals in your arsenal.)

    Larry

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    Maine-iac's Avatar
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    Quote Originally Posted by Donald Qualls

    FWith some divided developers, one needs to also watch for oxidation of the developing agent -- Divided D-76 is one where brownish discoloration of Bath A may be cause for replacement, just as it would be with stock solution of conventional D-76. Discoloration of Bath B is generally unimportant with true divided developers.
    Actually when Bath A is only slightly brownish or yellowish, it's fine. Most Bath A's will oxidize to a light brown fairly quickly, but will stay potent for several months. I replace my Bath A's about every six months or so.

    Larry

  5. #15

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    Gainer Vitamin C

    The Gainer Vitamin C developers are easily made as seperate stocks and by changing dilutions very nice for paper and film. I have worked with the metol versions only. Very, Very inexpensive.

  6. #16
    John Bartley's Avatar
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    Quote Originally Posted by Ole
    I hope I haven't done that - you list three very different alkalis there!
    Metaborate can be made by mixing borax and lye at a very exact ratio, and is more alkaline than borax. "Washing soda" I believe is sodium carbonate, which is even more alkaline.
    All these alkalis can be used as bath "B", however. They will also give different results!
    Hmmm...now I wish I'd stayed in school

    A quick guess here. Will a stronger alkali cause a faster development in the "B" bath due to more vigourous activation of the developer?

  7. #17
    Donald Qualls's Avatar
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    Quote Originally Posted by John Bartley
    A quick guess here. Will a stronger alkali cause a faster development in the "B" bath due to more vigourous activation of the developer?
    Yes, stronger alkali causes increased activity with almost all developers. In a divided developer, however, this is limited by local exhaustion in highlights, so you will see less increase in contrast compared to what you might see in a conventional developer with a change to higher pH. What you likely will see in divided developer is a slight increase in mid-tone contrast, plus a change in the character of grain (borax tends to soften grain anyway, compared to carbonate). This is modified, of course, by the amount of sulfite present in the B bath.

    Yep, lots of variables -- but FWIW, Anchell & Troop consider the Divided D-76 that puts half the sulfite of the original D-76 formula in each bath as the best of the lot, using the original borax alkali.
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  8. #18

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    Borax is an alkali though it does not serve as such
    in D76. I say that though the sulfite is half the usuall
    amount, as you have stated. Borax is though
    an alkali. Is that all you ment to say? Dan

  9. #19

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    Quote Originally Posted by Maine-iac
    Check out my article in the "Chemistry Recipes" section on Divided Paper Developers. In addition to formulas, it gives a description of the technique and its advantages.

    If you like to play around a bit, I experimented for awhile with a developer I called D-23C. I reduced the amount of sulfite considerably and added a bit of ascorbic acid which is also superadditive with Metol. Worked well. But later, I became more attached to the Phenidone/Vitamin C formulas that Pat Gainer worked on, and that he and I and others have given formulas for in other posts on this forum. I rarely use Metol anymore or Sulfite (one of the more expensive chemicals in your arsenal.)

    Larry

    Could you share this D-23C formula with us?

  10. #20
    Donald Qualls's Avatar
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    Quote Originally Posted by dancqu
    Borax is an alkali though it does not serve as such
    in D76. I say that though the sulfite is half the usuall
    amount, as you have stated. Borax is though
    an alkali. Is that all you ment to say? Dan
    Some confusion here, I think -- what you're saying is correct of sodium sulfite, which is the only alkali in traditional (undivided) D-23, but D-76 has borax as the accelerator, making the pH higher than sulfite would alone. The Divided D-76 I was referring to has the metol, hydroquinone, and half the sulfite in Bath A, and the remainder of sulfite and the borax in Bath B -- and in fact likely would produce some very slow development in Bath A alone (just as D-23 does with only metol and sulfite), because the sulfite is slightly alkaline.

    In general, unless there's a buffering agent present, the pH of a solution is determined by the strongest alkali present -- so if you have both sulfite and borax, the borax determines the pH and we use the shorthand of saying the borax acts as the accelerator or alkali in that developer. If there were (for some reason) both borax and sodium carbonate, the carbonate would act as the alkali because it produces a higher pH than the borax (one might do this with very low levels of carbonate to produce a graded developer, which will exhaust from high activity to low via neutralization of the tiny amount of carbonate, allowing pH to drop to that provided by the borax -- though I've never heard of a developer that does this). Sulfite, in most developers, acts only as a preservative (and silver solvent, if there's enough and the developing time is long enough), because there is a stronger alkali present in sufficient quantity not to be neutralized during development.
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

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