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  1. #41
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    pH. Also developing time. I usually need 10 minutes in PC-TEA 1:50 to do the same job. PC-TEA you throw away after use. The PC-Borax can be reused numerous times. I still like PC-TEA. Neither has sulfite. I doubt you would get any more satisfactory results by adding a significant amount of sulfite, but that depends on what satisfies you. Photography is all about self-gratification, after all.
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  2. #42

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    I was comparing the PC-Borax with PC-Glycol using a borax solution as activator. It has the same ingredients (apart from glycol), but lower amounts of P and C, and the development times are quite similar. So, as long the pH is the same, the actual amounts of ascorbic acid and phenidone don't matter as long as there's enough of it?

    You say PC-Borax can be reused, so how about the storage life of it? The reason I'm using PC-Glycol is because It keeps so well.

  3. #43

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    I had use PC-Glycol mainly with sodium metaborate as activator or a 5+5 grams per liter of sodium carbonate and borax. results are quite the same.
    I never use the borax as activator, may I know the amount of borax request per liter of working solution.
    Did you notice some changes in results compared with other activators?
    Have you made experiences and compared results with different activators with PC-Glycol developing FP4 and HP5?

  4. #44
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    I first used triethanolamine as activator for PC-Glycol. That is where I got the idea for using TEA as both solvent and activator.
    I have not used borax with PC-Glycol. See the APUG Chem article "Experiments with Metol and ascorbic acid." PC-Glycol is quite a different animal when used with TEA as activator. Borax is a remarkable buffer. I have been using 25 g/l with 8 or 9 g/l of ascorbic acid and adding various amounts of Metol or Phenidone or p-aminophenol in experiments. If you want to try borax as activator for PC-Glycol, I recommend testing it with 25 g/l of working solution. That is about saturated, so there's no use trying to make a concentrate, but you can keep a saturated borax solution for a long time, so if it works to your satisfaction, make a lot of it and use it full strength to dilute the PC-Glycol. Meanwhile, I will give it a try. Borax is pretty cheap and is available many places where TEA would have to be mail-ordered.
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  5. #45
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    Borax works well with PC-Glycol. If I tell you all an exact amount, you will get the idea that the precision and accuracy of measurement are critical. I will just say that 1/4 measuring cup of borax to a gallon or 4 liters is good for diluting PC-Glycol. I am not saying that 1 gallon = 4 liters, but that the pH of the working solution will not be different over at least that range of measurement precision.

    I think that the major effect of concentration of a borax activator is on the time constant of the local change of pH due to developer activity. This rate will change also with agitation. The equilibrium pH before and after development will be the same for practical purposes.

    I used Arista 400 EDU Ultra for this first test. I bracketted exposures + and - 1 stop in shutter speed. All three were usable. Resolution and sharpness were quite good. Next I will try FP4+.
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  6. #46
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    I really like FP4+ with either PC-TEA diluted with water or PC-Glycol diluted with the saturated borax solution. I developed it 10 minutes at 70 F with agitation for 10 seconds of every minute.
    Gadget Gainer

  7. #47

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    Finally Pat I completed the experiment with PC-Glycol with 25 grams of borax per liter of working solution as activator and to complete the test, since I have now a good amount of TEA,
    PC-Glycol+TEA as activator.
    For first test I developed two 120 rolls, one HP5 other Forte 400, developing time 9 minutes at 20C with 30 seconds of agitation at the start and gentle 10 sec. every minute, the results was good for the HP5, Forte 400 needs a minute and half more.
    I made some comparison prints with other HP5 developed in PC-Glycol with Sodium metaborate and Sodium carbonate (not together) as activator and the one with borax is the worst of the three, the contrast is not so good and tone a little bit too faint.
    The PC-Glycol with TEA as activator is very, very good always used with HP5, for this experiment I have not yet a comparison
    So at the end I will use borax with lye to have a "home made" sodium metaborate and I will mix next batch of PC in TEA.

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