102 print developer storage as working solution

"Nicholas O. Lindan" <see RemoveThis @sig.com> wrote in message
news:13fn8aghrj44f57@corp.supernews.com...
> "Lloyd Erlick" <Lloyd at @the-wire. dot com> wrote
>
>> Edwal 102 (Potassium version).
>
> Something like:
> H20 1l
> P.Sulfite 100g
> TSP 125
> Glycin 25
> P. Bromide 3
> (?)
>
>> I'm a little surprised to find a
>> developer that keeps a week in the form of a
>> partially used working solution.
>
> I believe it is Metol that's responsible for
> short tray life.
>
> Metol-less HQ, Glycin and Phenidone developers
> seem to last longer.
>
> Phenidone is often kept dissolved in 90+% isoproponol.
> I don't know if this is works with Glycin, I seem
> to remember Patrick Gainer mentioning Propylene Glycol
> as a keeping solvent.
>
> It is possible that a 1:4 liquid concentrate of
> Glycin and S. Sulfite would keep a long time.
>
> My guess is the actual ingredients of a bottle
> of Glycin are somewhat variable - in my experience
> it sometimes goes quickly, sometimes it lasts
> for a year.
>
>> Oh, I just thought of a question for the old
>> time experienced crew: would the ancient
>> practice of 'sweetening' or 'seasoning' a
>> freshly mixed batch of this developer with
>> ten or twenty per cent by volume of week-old
>> working solution be of any value? I've tried
>> this on several occasions with other
>> developers, and I have to admit I've never
>> seen the benefit.
>
> TTBOMK this is a practice used for motion picture
> developing where they want to keep the activity
> of the developer constant from the last film
> through a tank of old developer to the first
> film through a tank of fresh developer. Richard
> Knoppow would know: "Knoppow Knows" - does that
> count as nominative determinism?
>
> --
> Nicholas O. Lindan, Cleveland, Ohio
> Darkroom Automation: F-Stop Timers, Enlarging Meters
> http://www.darkroomautomation.com/index.htm
> n o lindan at ix dot netcom dot com
>
Evidently some chemicals keep better in solution than in
powder form. Ammonium thiosulfate, the basic ingredient of
"rapid" fixers is one. This is why rapid fixer is sold as a
liquid concentrate rather than a powder. I don't know if
this is true of Glycin. I think the main reason for the long
life of your working solution is that it was well protected
from air in storage. Kodak gives lifetimes for some
developers when used in tanks with lids as a week, the bag
should be better depending on what plastic its made of.
Adding some used developer to fresh can keep its
performance more uniform. As developer is used it
accumulates reaction products. Some of these, like Bromide
and Iodide, come from the film or paper, some are from the
developing agents. The reaction products are not consistent
in their effects, for instance, the reaction products of
Metol are restrainers but those of Hydroquinone are
accelerators. In general the presence of sulfite tends to
reduce the effects of these reaction products. Also, in
developers containing both Metol and Hydroquinone the two
tend to regenerate each other also reducing the effects of
the reaction products.
Although fresh developer can have Bromide added to it to
act as an anti-fog restrainer the effect may not be quite
the same as developer which has additional reaction products
in it. The practice of adding some old developer to fresh
developer is a way of trying to keep the developer more
uniform in action.
Motion picture practice changed over the years. In the
early days most negative processing, and probably most print
processing, was carried out in rack-and-tank units mostly by
hand. As the volume of work became greater some processing
began to be done in machines. After the introduction of
photographic sound recording the requirements for processing
control became very much greater than is needed for the
picture alone so the use of automatic machine processing
rapidly became standard practice. Also at about the same
time (late 1920's) research was begun on replenishing. By
about the early 1930's systems of replenisment were devised
to extend the life of the developer and insure uniformity in
machines. The research continued because early replenishment
systems were not entirely satisfactory. I don't have numbers
for the life of processing solutions in current machines but
its very long. The developer and other solutions in current
automatic processing machines is not only replenished by the
addition of more developer but regerated by removing
dissolved silver and some other chemicals.
For the most part replenishment of B&W developers for
home use is not too practical because the volume of use is
too little. However, simple replenishment according to
instructions can keep many developers going for very long
periods of time (over a year). Ideally, the developer
performance should be tested by sensitometric means but this
is really necessary only when very critical work is being
done.


--
---
Richard Knoppow
Los Angeles, CA, USA
dickburk RemoveThis @ix.netcom.com
 >> Stay informed about: 102 print developer storage as working solution 

On Sep 27, 4:14 am, Lloyd Erlick wrote:
>
> Recently I posted regarding a print developer
> I've been playing with lately: Edwal 102
> (Potassium version).
>
> Anyway, I'm a little surprised to find a
> developer that keeps a week in the form of a
> partially used working solution. In fact, I'm
> amazed and wondering if this isn't too good
> to be true. Could this be the reason Edmund
> Lowe (who invented this developer) specified
> phosphate in the formula? Is this part of the
> reason it keeps well?
l
> --le
>

Phosphate. The TSP or your TPP has a very high ph; above
by some measure that of S or P carbonate. I'm quite sure it is
specified because it will speed the processing of prints. As for
it's acting as an preservation agent I think that not possible. It
is as fully oxidized as any carbonate. In fact do to the high ph
of it's solutions it would be reasonable to expect a higher
rate of oxidation.

Likely the same print results could be obtained using P. carbonate
with longer development times. I've tested D-23 against Ansco 120
with same print results. Ansco 120 is a carbonated metol sulfite
developer while D-23 has only sulfite as activator.

I do not know why Glycin behaves as it does;
good wet poor dry. If I can think of something
convincing I'll pass it along. Dan
 >> Stay informed about: 102 print developer storage as working solution 

On Fri, 28 Sep 2007 03:57:24 -0700,
dan.c.quinn.DeleteThis@att.net wrote:

>Likely the same print results could be obtained using P. carbonate
>with longer development times. I've tested D-23 against Ansco 120
>with same print results. Ansco 120 is a carbonated metol sulfite
>developer while D-23 has only sulfite as activator.



September 28, 2007, from Lloyd Erlick,

Well, that's interesting. I can omit the
carbonate from my 120 developer and see no
difference in prits? Hmm. There must be some
catch. Lower capacity?

regards,
--le
 >> Stay informed about: 102 print developer storage as working solution 

"Lloyd Erlick" <Lloyd at @the-wire. dot com> wrote in
message news:4dppf35ikt91hu2povs6odcfhhus4p9227@4ax.com...
> On Fri, 28 Sep 2007 03:57:24 -0700,
> dan.c.quinn.RemoveThis@att.net wrote:
>
>>Likely the same print results could be obtained using P.
>>carbonate
>>with longer development times. I've tested D-23 against
>>Ansco 120
>>with same print results. Ansco 120 is a carbonated metol
>>sulfite
>>developer while D-23 has only sulfite as activator.
>
>
>
> September 28, 2007, from Lloyd Erlick,
>
> Well, that's interesting. I can omit the
> carbonate from my 120 developer and see no
> difference in prits? Hmm. There must be some
> catch. Lower capacity?
>
> regards,
> --le
>
It may affect maximum black and will certainly affect
contrast. Print developers are made active both to make them
fast and because prints are developed to the maximum
contrast and density the emulsion is capable of. Negative
film is usually developed to a considerably lower contrast
and maximum density than the emulsion is capable of.
TSP is certainly more alkaline than Carbonates but I
rather think its used in developers at least partly because
its a sequestering agent for dissolved minerals in the
water. This is what makes it an effecient cleaning agent.
I have seen formulas for negative developers containing
some TSP for machine processing of motion picture film so it
can be used in low contrast developers.
I agreew with Dan Quin that there is probably little or
no effect on developer life but I am not an expert chemist
so there could be some effect I've never heard of.


--
---
Richard Knoppow
Los Angeles, CA, USA
dickburk.RemoveThis@ix.netcom.com
 >> Stay informed about: 102 print developer storage as working solution 

On Sep 28, 2:03 pm, "Richard Knoppow" wrote:
>
> >"Lloyd Erlick" wrote
> > Well, that's interesting. I can omit the
> > carbonate from my 120 developer and see no
> > difference in prits? Hmm. There must be some
> > catch. Lower capacity? le
>
> It may affect maximum black and will certainly affect
> contrast. Print developers are made active to make them
> fast and because prints are developed to the maximum
> contrast and density the emulsion is capable of. Negative
> film is usually developed to a considerably lower contrast
> and maximum density than the emulsion is capable of.
>
Max black and contrast twixt a D-23 and Ansco 120
processed print are same. My formula D-23 is 8 grams
metol and 80 grams sodium sulfite, water to make 1 liter.
The working strength was 1:1, volume 1/8 liter and as
much as 8 minutes in the developer. The Ansco 120
was used at a 1:11 dilution, 1/8 liter, one-shot;
perhaps 3 minutes.

So a sulfited only metol developer will produce a same
print as a carbonated metol sulfite developer. What's so
unexpected of that given the amount of additional time it
takes to do it? I'm not saying it's practicle.

I'm only pointing out to Mr. Erlick that he could substitute
potassium carbonate for the potassium phosphate. As with
the sulfite powered D-23 and carbonate powered Ansco 120
he could expect identical results. And it might be practicle.
All we are talking about is the activation ph; the lower the
longer the processing.
>
> TSP is certainly more alkaline than Carbonates but I
> rather think its used in developers at least partly because
> its a sequestering agent for dissolved minerals in the
> water. This is what makes it an effecient cleaning agent.
>
Do not confuse TSP or TPP with the metaphosphates;
the Calgon type phosphates. Neither TSP or TPP poses
any complexing properties.
>
> I have seen formulas for negative developers containing
> some TSP for machine processing of motion picture film so
> it can be used in low contrast developers.
>
Film or paper, pull it soon enough and the contrast
will be low. Give a film plenty of exposure and as with
paper, with enough time in the developer it will produce
maximum black. Many film developers make good print
developers. To speed them add a little carbonate. I think
Kodak's D-78 may make a good Glycin print developer.
Sodium sulfite, Glycin, and Sodium carbonate; 3 and
3 and 6 grams in that order. Water to make one liter.
Gotta try that myself one day. I'll leave the dilution
to the reader. Dan
 >> Stay informed about: 102 print developer storage as working solution 

On Sep 27, 4:14 am, Lloyd Erlick <Lloyd at @the-wire. dot com> wrote:


> This actually raises an interesting
> "difficulty" -- Glycin does not keep well in
> dry powder form, and if a working strength
> developer solution will keep well, the length
> of time required to use up the supply of
> Glycin is extended. I bought 250 grams, which
> is starting to look like much too much for
> one time. I've heard there are ways to keep
> Glycin in solution form better than in
> powder, but I've never learned details or
> tried it myself.

Freeze the powder. I have glycin in my freezer from 19 months ago and
it looked good as new this week.
 >> Stay informed about: 102 print developer storage as working solution