Thread: Fomadon-P = D-76d.
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Old July 30th 09, 08:46 AM
Keith Tapscott. Keith Tapscott. is offline
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First recorded activity by PhotoBanter: Feb 2005
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Originally Posted by Richard Knoppow View Post
"Keith Tapscott."
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Has anyone tried this developer?

http://tinyurl.com/kqegre




--
Keith Tapscott.

I have not tried it.
I did a little searching around. The box suggests its
D-76d, which is the buffered form of D-76. Kodak's packaged
D-76 is of this type. The buffered formula was devised in
1929, a couple of years after the release of the original
D-76 formula, because it was found that the original slowly
increased in activity causing a significant increase in the
contrast obtained after a given developing time. Kodak labs
found that the pH of the solution increased slowly with time
and that using a borax-boric acid buffer system would
control it. There is an MSDS for the Foma product at the
Freestyle site but its wrong listing sodium thiosulfate
(hypo) as one of the ingredients. Of course, they mean
sodium sulfite. The only other ingredients listed are metol
and hydroquinone so its incomplete in any case.


Kodak D-76 (original 1927 formula)
Water (at about 125F or 52C) 750.0 ml
Metol 2.0 grams
Sodium Sulfite, desiccated 100.0 grams
Hydroquinone 5.0 grams
Borax, granular 2.0 grams
Water to make 1.0 liter

Dissolve chemicals in order given.

Kodak D-76d (1929 buffered formula)
Water (at about 125F or 52C) 750.0 ml
Metol 2.0 grams
Sodium Sulfite, desiccated 100.0 grams
Hydroquinone 5.0 grams
Borax, granular 8.0 grams
Boric acid, crystalline 8.0 grams
Water to make 1.0 liter

Do not use powdered Boric acid, it dissolves only with
difficulty.
Mix chemicals in order given.

The two formulas have about the same activity when
freshly mixed but the buffered version is stable where the
original is not.



--
Richard Knoppow
Los Angeles, CA, USA
Richard, you say that: "The two formulas have about the same activity when freshly mixed but the buffered version is stable where the
original is not."

I have been researching D-76 (ID-11) and it`s derivatives for quite a few years now, including mixing some of the formulas from scratch. I have to say that I disagree that D-76 and D-76d have the same activity and that the buffered-borax version needs significantly longer development times to match the film contrast of those films which were developed in the commercial formula.
I also found that the standard formula seems to match the commercial D-76 developer for developing times, unlike D-76d.
Ryuji Suzuki provided some useful data about D-76 and it`s variants on his website. The MSDS for D-76 list diboron trioxide/B2O3 (boric anhydride), but from correspondence with a former employee at Kodak, is that D-76 commercial is identical to the published product, although there is a special method for encapsulating the developing agents, so they are protected against the other constituents in the single-powder. There are patents for packaging single-powder developers which you may be of interest to you.
It wasn`t until recently that I noticed the Foma Fomadon-P packaging that gave me a clue as to why the development times are radically different.
Take a look at the MASSIVE DEVELOPMENT CHART on the Digital Truth website for Fomadon-P.