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  1. #1
    Maine-iac's Avatar
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    Hydroquinone in Phenidone/Ascorbic acid developer

    If I want to experiment with a Phenidone/Hydroquinone/Ascorbic acid paper developer to replace my metol-based standard, what's the appropriate ratio of HQ to the Phenidone? Does the addition of the HQ make any difference in the amount of Ascorbic acid?

    Larry

  2. #2
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    A convenient way is to use HC110 and add ascorbic acid and carbonate. It was in one of my P.T. articles a few years ago, but I don't remember the ratios I used. I would say that 10 or 15 ml of HC110 and a teaspoon or so of ascorbic acid powder and a tablespoon of sodium carbonate in a liter of water would get you about a 2 minute paper developer.
    Gadget Gainer

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    I was under the impression that ascorbic acid was a substitute for hydroquinone??? If so, wouldn't it be redundant to add it to a mix that already has ascorbic acid in it? I'm reaching here, so please correct me if I'm wrong.

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    Maine-iac's Avatar
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    Quote Originally Posted by jim appleyard
    I was under the impression that ascorbic acid was a substitute for hydroquinone??? If so, wouldn't it be redundant to add it to a mix that already has ascorbic acid in it? I'm reaching here, so please correct me if I'm wrong.
    In my understanding, Jim, both are superadditive with Phenidone. But from past experience, developers with HQ added, even with ascorbic acid, will have greater contrast and more activity. I don't profess to understand the full chemical properties, but I think the ascorbic acid is a preservative for Phenidone, though HQ is not. I might be wrong, and someone will surely correct me if I am.

    I tried a paper developer using only Phenidone and Ascorbic acid, but prints came out flat and with weak blacks. This may be because I always use a divided developer for printing, keeping the sodium carbonate for Bath B. But when I use a regular Dektol-type metol/HQ/sulfite or ascorbic acid Bath A, I get really nice results. So I'm trying to eliminate the metol and sulfite and see if I can get equally good results with Phenidone/HQ/ascorbic.

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    Maine-iac's Avatar
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    Hadn't thought of using HC110, Pat, but it makes sense. I'd split out the carbonate for Bath B, however, since I always use divided development for paper.

    Larry

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    Hey, give it a go. Many great inventions were created like this.

  7. #7

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    There is no advantage in adding hydroquinone to phenidone-ascorbate developers. If you can't obtain good density and contrast from straight forward phenidone ascorbate develoers like DS-14, it is probably a problem in your formulation, not in the agents selected. There is no advantage in using two bath print developer. There is probably bigger disadvantages in doing so.

    Quote Originally Posted by Maine-iac
    In my understanding, Jim, both are superadditive with Phenidone. But from past experience, developers with HQ added, even with ascorbic acid, will have greater contrast and more activity. I don't profess to understand the full chemical properties, but I think the ascorbic acid is a preservative for Phenidone, though HQ is not. I might be wrong, and someone will surely correct me if I am.

    I tried a paper developer using only Phenidone and Ascorbic acid, but prints came out flat and with weak blacks. This may be because I always use a divided developer for printing, keeping the sodium carbonate for Bath B. But when I use a regular Dektol-type metol/HQ/sulfite or ascorbic acid Bath A, I get really nice results. So I'm trying to eliminate the metol and sulfite and see if I can get equally good results with Phenidone/HQ/ascorbic.

  8. #8
    Maine-iac's Avatar
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    Quote Originally Posted by jdef
    Hi Larry.



    This is my standard paper developer. It keeps very well, and has amazing capacity.

    Jay
    Thanks Jay, I'll try it. Can't figure out the sulfite, however. Shouldn't need it in a PC, but maybe because of the HQ.

    Larry

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    I've done both. There is at least one commercial product that combines hydroquinone and ascorbate but the aim of that combination is to improve solution stability. That approach is not that effective (and the product is notorious for this).

  10. #10
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    Granted. However the HC110 serves as a convenient source for everything but the ascorbic acid-carbonate and the little bit extra Q doesn't seem to hurt. I certainly wouldn't go out and get HC110 if I didn't have any on hand, and if you have metol left over, you can use 1/4 tsp. metol, 1/2 tbs. ascorbic acid and 1 tbs. sodium carbonate in a liter or quart of water. When the metol is gone, about 1/10 of that amount of phenidone can be substituted. 1/40 of a teaspoon is really small, so make a 1% solution of phenidone in alcohol or glycol and use 5 ml per liter of working solution. Ryuji is right about the hydroquinone. It never will be missed, no it never, never, never will be missed.
    Gadget Gainer

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