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  1. #41

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    Quote Originally Posted by clay
    It's been years since i mixed up PMK, and it just occurred to me: was I supposed to dissolve the metol BEFORE the pyrogallic acid? I seem to remember that the metol is supposed to go in first. I did it the other way....

    I had both chemicals in the same container and just poured them in together with stirring. Everything went completely into solution within about two minutes or less.

  2. #42

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    Quote Originally Posted by jdef
    I've been told that Metol will not dissolve in glycol ( I assumed the same for TEA), and that phenidone is the logical alternative for this application. I guess just about anything will dissolve given a high enough temperature, but I wonder how these high temperatures might affect the working properties of the resulting developers. I have concentrates of P-TEA and PC-TEA on hand, and simply mix the two 50/50 to make what must be a very similar developer to PM-TEA, which I call PCP-TEA. Last night I made up a batch of QP-TEA, and was surprised at the long developing times (20 min. for Ultrafine 125). I expected QP-TEA to be about as active as the PG/PQ developer with sodium carbonate and borax, but apparently it is not. I was also surprised by the very minimal stain compared to the PG/PQ. I haven't printed the QP-TEA negatives yet, so I can't comment further on that developer. The PCP-TEA, however is proving to be a very good staining developer, with activity similar to PC-TEA, and stain similar to P-TEA. Patrick has suggested that a pinch of sulfite might be needed to activate the superadditivity between the Pyrogallol and Phenidone, but I haven't tried that yet. The light looks great outside my window, so maybe I'll go expose a roll or two and try it.
    Hi, my experience with Metol is that even if you go up to 300F, Metol will not dissolve in PG. On the other hand, Sandy and several others have reported success dissolving Metol in TEA at temperatures around 250F.

    My experience with PQ-PG (Phenidone/Hydroquinone/Polyethylene Glycol activated with Sodium Carbonate) is that if the dilution is too great, PQ-PG becomes very inactive and increasing the amount of alkali doesn't help much. PQ-PG works ok at 1:1:100, at 1:1:200 its activity drops off a cliff.

    I discovered this while making direct comparisons with PC-PG (Phenidone/Pyrocatechol/Polyethylene Glycol activated with Sodium Carbonate). The PC-PG combination retained its activity at much greater dilution levels than the PQ-PG.

    I did not use either sulfite or KBr in any of this testing.
    Tom Hoskinson
    ______________________________

    Everything is analog - even digital :D

  3. #43
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    Tom,

    Part of this problem may be the lack of sulfite in the PQ formulation. Sulfite is necessary to the superadditivity beteen the P and the Q. A very small amount will sufice, but some is necessary. I appears that the formation of hydroquinone monosulfonate is a necessary step in that synergism. OTH, the PC formula does not need sulfite for synergism.

    I have not tried 1:1:200 with either one, but I'd be willing to bet that the PQ-Glycol would look more like the PC-Glycol if you added a gram or so of sulfite to the working solution.
    Gadget Gainer

  4. #44
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    I mixed a batch of P-TEA and tried it 1:150 with tubes, minimal agitation (the same way I use Pyrocat-HD). After fixing, when I turned the lights on, the spent developer was the ugliest dark brown-black mess I've ever seen, but the negatives seemed to develop OK. I'm still zeroing in on times, but it looks as though this method of development will work just fine.
    juan

  5. #45
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    Quote Originally Posted by juan
    I mixed a batch of P-TEA and tried it 1:150 with tubes, minimal agitation (the same way I use Pyrocat-HD). After fixing, when I turned the lights on, the spent developer was the ugliest dark brown-black mess I've ever seen, but the negatives seemed to develop OK. I'm still zeroing in on times, but it looks as though this method of development will work just fine.
    juan
    I tried minimal agitation development with rollfilm in P-TEA (400TMax) and got unbelievable fog and a great deal of mottling. The negatives are incredibly sharp but I'm not particularly sanguine about how they'll print.

    What film did you use?

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