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  1. #21
    Maine-iac's Avatar
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    Quote Originally Posted by Tom Hoskinson
    Take a look at the Ascorbic Acid paper formulas in the APUG Chemistry section.



    Try adding more phenidone. BTW, phenidone goes off fairly quickly in alcohol so dissolve it just before you use it. Don't try to keep a stock solution in alcohol.
    Where did you get this notion? I have kept a 1% Phenidone solution dissolved in alcohol for months and months with no degradation. You must use 90% alcohol rather than the 70% variety, but I mix it up in 100 ml batches, which with my formulas (they call for 4 ml per liter) lasts a long time. I've kept the stock for nearly a year before it's gone off.

  2. #22

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    Quote Originally Posted by Maine-iac
    Where did you get this notion? I have kept a 1% Phenidone solution dissolved in alcohol for months and months with no degradation. You must use 90% alcohol rather than the 70% variety, but I mix it up in 100 ml batches, which with my formulas (they call for 4 ml per liter) lasts a long time. I've kept the stock for nearly a year before it's gone off.
    Results vary. I used 90 percent rubbing alcohol and noticed a reduction in activity after a few months.

  3. #23

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    Quote Originally Posted by Maine-iac
    Where did you get this notion? I have kept a 1% Phenidone solution dissolved in alcohol for months and months with no degradation. You must use 90% alcohol rather than the 70% variety, but I mix it up in 100 ml batches, which with my formulas (they call for 4 ml per liter) lasts a long time. I've kept the stock for nearly a year before it's gone off.
    I got my notion from my own testing and results reported by Pat Gainer and others.

    I have a bottle (100ml) of 1% Phenidone dissolved in 90% Isopropanol and a 100ml bottle of 1% Phenidone dissolved in technical grade Polyethylene Glycol. I made these two solutions on the same day about a year ago. The alcohol solution has degraded, the Polyethyene Glycol solution has not when compared with fresh solution (all mixed with the same batch of dry Phenidone powder).

    Recall that alcohols in general are water grabbers and Phenidone oxidizes in water. The dryer the alcohol, the longer the stock solution will last.
    Tom Hoskinson
    ______________________________

    Everything is analog - even digital :D

  4. #24
    glbeas's Avatar
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    I found some stuff called Fruit Fresh at Wally World which has listed in order, Dextrose,Ascorbic Acid, Citric Acid, Silicon Dioxide. Contains no sulfites. This is for canning and whatever. How well do you think this will work? Anybody know an approximate percentage of ascorbic in this product?
    Gary Beasley

  5. #25

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    Quote Originally Posted by psvensson
    Ok, I found some tests I've done that illustrate the effect of sulfite. This is a case where sulfite is not the only accelerant - in fact, the developer works fine without it.

    I exposed a roll of Delta 400 35mm and cut it in three. Each strip was developed in:

    1l water
    0.5 tsp ascorbic acid
    4 ml phenidone/alcohol solution a la Gainer
    20 ml TEA
    9 minutes at 76 F

    Plus added sulfite as follows:
    Strip 1: No sulfite. Contrast 1.14
    Strip 2: 0.5 tsp sulfite. Contrast 1.29
    Strip 3: 2 tsp sulfite. Contrast 1.38

    To me that looks like sulfite has an effect on activity that doesn't spring from its effect on pH, but it's short of conclusive proof.
    "... sulfite is not the only accelerant" So, without the sulfite it must
    be the TEA that makes it go.
    Those "contrast" numbers look to me like maximum negative "densities"
    You've a densitometer but no ph meter?

    According to Patrick Dignan, phenidone works at a lower ph than metol.
    The TEA may make it go some but adding sulfite may very well
    up the ph and activity.

    BTW, the above formula is a long way from E-76. It is though a PC
    developer.

    Have you tried phenidone in bisulfite solution a la Dignan; One gram
    phenidone, 5 grams S. bisulfite, to make one liter? Dan

  6. #26
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    Triethanolamine (TEA) is an organic base. Without water, it does not ionize appreciably and so developing agents dissolved in it do not oxidize. You can make a developer concentrate with pyrogallol or catechol dissolved in TEA that only needs water to make it work. You can add a little metol or phenidone to the stock to make it more active, and a tiny bit of sulfite added to the working solution will make it more active yet. If you are looking for a staining developer, too much sulfite will defeat your purpose.

    I think the Fruit Fresh has too much other stuff in it. Better get ascorbic acid.
    Gadget Gainer

  7. #27

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    Quote Originally Posted by dancqu
    "... sulfite is not the only accelerant" So, without the sulfite it must
    be the TEA that makes it go.
    Yep. 20ml TEA to a liter of water is the same amount as PC-TEA 1:50.

    Quote Originally Posted by dancqu
    Those "contrast" numbers look to me like maximum negative "densities"
    Yes, that's Zone VIII density minus Zone I density.

    Quote Originally Posted by dancqu
    You've a densitometer but no ph meter?
    I think most photographers would get a densitometer before a pH meter. As it happens I don't even have a densitometer - I improvise with a light meter. Accuracy is probably +-0.05 units.

    Quote Originally Posted by dancqu
    BTW, the above formula is a long way from E-76. It is though a PC
    developer.
    I know. It was just a handy example of the effect of sulfite. For actual developing I've been using more sulfite, and borax instead of TEA; a formula very close to E-76 1:1. Right now I'm dispensing with the borax and just using phenidone, ascorbic acid and sulfite. Works really well.

    Quote Originally Posted by dancqu
    Have you tried phenidone in bisulfite solution a la Dignan; One gram
    phenidone, 5 grams S. bisulfite, to make one liter? Dan
    Thanks for the suggestion. I may try it, but intuitively it seems to make more sense to dissolve the phenidone in something like glycol or TEA.

  8. #28
    glbeas's Avatar
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    I was poking through the cabinet getting out stuff to try this developer out with and noticed the old bottle of Print Flattening solution. A closer look at the label reveals the stuff is ethylene glycol. And I thought I'd have to do some looking to findstuff like that for my phenidone!

    Now what was that ratio to make the 1% solution? 1 gram to 100ml glycol?
    Gary Beasley

  9. #29
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    If it's not pure or at least tech grade ethylene glycol, don't bother with the print flattening solution. You would do better with automobile antifreeze, which is mostly ethylene glycol or, it it is the safe kind, propylene glycol.
    Gadget Gainer

  10. #30
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    Is there a particular brand you would recommend? Im kinda put off by the brightly colored dyes I see in most of them.
    Gary Beasley

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