[pure-silver] Re: Sulfite stabilization
- From: "John Black" <jblack@xxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Sat, 7 May 2005 14:50:24 -0400
> I get about 0.1 to 0.2 unit higher fog with Phenidone (v. Dimezone S)
> in DS-10 with pre-2002 Plus-X. That's still one of my standard test
> film. I haven't found more recent test film yet.
Interesting. I get about the same fog level with phenidone bearing
developers (JB9) that I got with Xtol. That may be due to the lower level
of phenidone (50mg/L @ pH 8.3) that I use. The equivalent activity with Xtol
is at 1:5 (1+4) which is about the same level of dimezone-S. I don't use
higher concentrations of phenidone exactly because of it's tendency to fog.
I put up with a little mor fog in the 3200 films because they must be
overdeveloped anyway.
>
> MSDS doesn't tell you those info to any useful degree for developer
> work. You would need to know what types of reactions occur under what
> circumstances, and what are the products, etc.
Agreed.
> > As in Dimezone-S versus phenidone.
>
> The analogy would be a lot closer if you compared Phenidone B or
> Dimezone versus Dimezone S. (Phenidone A is not substituted at the 4
> position.) But that's about solubility; dispersion is not going to
> help anyway.
I thought dimezone was a 2X methyated phenidone that improved water
solubility and dimezone-S was a hydroxy-methyl derivitive of dimezone that
improved oxidation resistance. Do I have it backwards?
>
> I don't find his tales interesting. Sorry but I'm seeking useful
> solutions not stories for which the right answers exist. I am pretty
> sure you would feel the same in the field in which you are good at...
>
Ah but I consider everyone's data, dismissing nothing out of hand and try it
out to see if it can be reproduced. I find Gainer's data about PC solutions
in glycols for aerial stability to be very useful. He is, I think, wrong
about buffers, pH and sulfite however. You, however, have some wonderful
tricks on preservation and fixation with some very useful formulae that I
use frequently but I disagree with you on some relatively minor points such
as the level of sulfite that is optimal and the utility of TEA.
No one is right all of the time and no one is always wrong. Everybody has
something to contribute.
JB
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