It makes sense that where the packaged powders come as a
single powder they can be divided provided they are thoroughly
mixed before the division. Kodak had some magic, and I remember
reading what they did, which allowed them to combine chemicals
that previously had to be mixed in specific order. For instance,
if you look at developer formulae containing Elon (Metol) you
will find it is dissolved first. That is because Metol does not
dissolve well in a solution of sulfite. Even though it makes
sense that the sulfite should be dissolved first to prevent
oxidation of the Metol it turns out the Metol will become very
hard to dissolve especially in developers like D-76 that have a
high concentration of it. So, Kodak does something that allows
all the constituents to be dissolved at the same time. I think
there is also a method of treating the alkalies, perhaps its what
Bob Kiss described.
In old Kodak chemistry books its made clear that the order of
solution is critical and some formulas won't work if mixed out of
order. I go back far enough to remember when many developers were
packaged in two parts, which were to be mixed in order. D-76 was
one of them and I suspect the A package had the Metol in it. Its
possible the reason some developers don't mix completely or are
slightly colored has to do with whatever reactions need to take
place. For instance, D-76 often has some residual crystals in it.
These usually disappear overnight. I also suspect that water
temperature can make a difference. In any case, from What Bob
Shanebrook says the packages are made from a single powder in a
hopper and is kept stirred. So, it would seem that one could
divide the contents of a large package into smaller ones provided
it was agitated before doing so. Of course, the real way to find
out is to do the division, mix the smaller amounts of whatever it
is, and analyze each chemically. Good school project.
I would be somewhat concerned with the life of the divided
powders but if mixed and divided into stock solution I suspect
the results would be more vulnerable to aging.
All guesswork at this point.
A question for Bob Shanebrook: you refer to T-Max producing
similar results to D-76, I presume you mean plain T-Max and not
T-Max RS or do you? It seems to me the published curves for the
two are slightly different.
On 3/23/2021 10:35 AM, Robert Shanebrook (Redacted sender
makingkodakfilm for DMARC) wrote:
You may be right. I never paid attention to the powder manufacturing process. It was never a problem in my time, unlike today. I would see the quality and financial data and I worked through the manufacturing department a few times. It didn't require attention. "If it isn't broken don't fix it!"
On Tuesday, March 23, 2021, 10:07:56 AM EDT, BOB KISS <bobkiss@xxxxxxxxxxxxx> wrote:
DEAR ROBERT,
I guess I was wrong about the "mono-crystals"?Hmmm...I could have sworn that some Kodak chems were offered as mono-crystals...
CHEERS!
BOB
*From:*pure-silver-bounce@xxxxxxxxxxxxx [mailto:pure-silver-bounce@xxxxxxxxxxxxx] *On Behalf Of *Robert Shanebrook (Redacted sender "makingkodakfilm" for DMARC)
*Sent:* Tuesday, March 23, 2021 9:22 AM
*To:* pure-silver@xxxxxxxxxxxxx
*Subject:* [pure-silver] Re: Kodak D76 Developer
I have hesitated to comment on this but I can't resist.
The reason mixing partial packs is not recommended is that the components stratify because of particle size and density.
When Eastman Kodak Co. manufactured it we didn't individually add each component to individual packages. Rather we made a big hopper of the powder, kept it well stirred and dispensed it into the individual packages. Proper distribution of components was confirmed by chemical analysis and statistical analysis.
We discouraged package splitting because we learned users couldn't be depended on to thoroughly mix the dry material.
If you are still concerned with making small batches of developer use T-Max Developer. It provides the same curve shape and image quality, is liquid (stir before dispensing), and has excellent long term shelf keeping characteristics.
RS
On Tuesday, March 23, 2021, 08:45:54 AM EDT, Ben R. McRee <ben.mcree@xxxxxxxxx> wrote:
FWIW you can buy Ilford's equivalent ID-11 in smaller quantities. You probably won't save any money, but you also won't be mixing up chems you'll have to store long term.
--Ben
On Mon, Mar 22, 2021 at 11:14 PM hksvk <hksvk@xxxxxxxxxxx <mailto:hksvk@xxxxxxxxxxx>> wrote:
As solutions are removed from glass containers with
tight-fitting screw-on caps, adding glass marbles to reduce
the headspace works very well. I add marbles to keep the
level of solution well into the neck of the containers or
very close to the top of cylindrical containers. This way I
can still pour out solution without it slopping all over
the place. When the remaining volume of solution reaches
the capacity of the next smaller glass container, it gets
decanted to that smaller one. Hope this helps.
Harry.
> On Mar 22, 2021, at 10:00 PM, `Richard Knoppow
<dickburk@xxxxxxxxxxxxx <mailto:dickburk@xxxxxxxxxxxxx>> wrote:
>
> It has been suggested that the developer be used
one-shot. IMO a good idea. D-76 works fine when diluted 1:1
and used that way. The developing charts have times for
most films with diluted developer. In fact, it has an
advantage that its easier to control the uniformity of
development with the longer times.
>
> On 3/22/2021 6:01 PM, Brian Smith (Redacted sender
smithcbrian2 for DMARC) wrote:
>> The reason why it is a bad idea not to make up the full
amount is that, as the contents of the packet are mostly
sulphite (maybe 100g per litre) and the quantity of
developing agents is very small (just a few grams per
litre), there's no way of ensuring that any part-packet
amount will contain the correct proportions of the
developing agents.
>>
>> I make up print develop a US gallon at a time and store
it in small brown bottles filled to overflowing. I've never
had it go off.
>>
>> Brian
>>
>> On Tuesday, 23 March 2021, 01:41:34 pm NZDT, Tim
Daneliuk <dmarc-noreply@xxxxxxxxxxxxx
<mailto:dmarc-noreply@xxxxxxxxxxxxx>> wrote:
>>
>>
>> On 3/22/21 4:33 PM, Louis Smit (Redacted sender lsmit
for DMARC) wrote:
>>
>> > Hello Everybody,
>> >
>> > I have a question about D76. Can I divide the content
into smaller amounts so that I can mix smaller volumes at a
time? I do not use a full batch until after the 12 month
shelf life is over and wonder if it is possible to mix
smaller batches. Some opinions out there seem to indicate
that it is not advisable as the powder my not be uniformly
mixed. Is that a concern?
>> >
>> > Thank you,
>> >
>> > Louis Smit
>> > Coquitlam BC, Canada.
>>
>>
>> As others have mentioned, this is a bad idea. However,
making the full
>> gallon and then pouring off into brown glass bottles
with polycone caps
>> is a perfectly reasonable thing to do. Never store
developer in plastic.
>> Most plastics are permeable to air and will not prevent
oxidation.
>>
>> That said, if you're really using such low volumes (or
even if you are not),
>> consider moving to a one-shot developer that you mix,
use and throw away.
>>
>> HC-110 Dilution B will give you similar results to D-76.
The stock solution
>> you buy from Kodak lasts forever. Even the working
solution can actually be
>> stored for a few weeks (again, in a brown glass bottle).
>>
>> As I recall, 1/2 gal of HC-110B is good for something
like 6 8x10 equivalents
>> (1 roll 35 or 120, 4 - 4x5s, or 2 - 5x7s) and will
easily keep in a
>> bottle for a month or so. Quite inexpensive.
>>
>> Another good choices for one-shot might be Rodinal.
>>
>> An even cheaper alternative is Pyrocat-HD which you can
mix yourself or
>> buy from Photographer's Formulary, though you need to be
more careful
>> with handling, skin protection, eye protection, etc.
with Pyrocat.
>>
>> Finally, if you really want to stick with D-76, you can
mix your own in
>> smaller quantities.
>>
>> https://lostlightphotography.com/kodak-d76-formula/
<https://lostlightphotography.com/kodak-d76-formula/>
<https://lostlightphotography.com/kodak-d76-formula/
<https://lostlightphotography.com/kodak-d76-formula/>>
>>
>> Chemicals are easily obtained from Artcraft but this
does incur heating
>> the distilled water, weighing and mixing everything
yourself.
>>
>> Again, anytime you mix your own chemistry you need:
>>
>> - Skin protection
>> - Eye protection
>> - A good face mask
>> - Ventilation
>> - Some kind of labcoat to protect your clothing
>> --
>>
----------------------------------------------------------------------------
>> Tim Daneliuk tundra@xxxxxxxxxxxxxx
<mailto:tundra@xxxxxxxxxxxxxx>
<mailto:tundra@xxxxxxxxxxxxxx ;<mailto:tundra@xxxxxxxxxxxxxx>>
>> PGP Key: http://www.tundraware.com/PGP/
<http://www.tundraware.com/PGP/>
<http://www.tundraware.com/PGP/
<http://www.tundraware.com/PGP/>>
>>
=============================================================================================================
>> To unsubscribe from this list, go to www.freelists.org
<//www.freelists.org> and logon to your account (the
same e-mail address and password you set-up when you
subscribed,) and unsubscribe from there.
>>
>
> --
> Richard Knoppow
> dickburk@xxxxxxxxxxxxx <mailto:dickburk@xxxxxxxxxxxxx>
> WB6KBL
>
>
=============================================================================================================
> To unsubscribe from this list, go to www.freelists.org
<//www.freelists.org> and logon to your account (the
same e-mail address and password you set-up when you
subscribed,) and unsubscribe from there.
To unsubscribe from this list, go to www.freelists.org
<//www.freelists.org> and logon to your account (the
same e-mail address and password you set-up when you
subscribed,) and unsubscribe from there.
