Storage Life Question About D-76 Solution
narke
litre, but I heard that I can only storage the developer for 2 weeks in
the normal temperature. My question is:
1) I think 1L is too much for me for I only take 2 rolls per month.
Could I only mix 1/4 L every time from raw ingredients (of course, I
will use 1/4 quantity of every ingrdients) ?
2) Is there any way to prolong the storage life of D-76? I got AP
platic black jug, does it help?
Thanks in advance.
-
narke
Richard Knoppow
D-76 should last a lot longer than 2 months. I use packaged D-76,
which may have a longer shelf life than the home mixed variety, I often
take six months to use up a gallon. I have had D-76 last nearly a year.
Kodak gives six months as the shelf life in a filled stoppered bottle
but Kodak figures on shelf life are usually very conservative.
Try storing in glass bottles rather than plastic. Even the best
plastic allows some air to penetrate. Also, when you mix it use water
which has been boiled for about five minutes and allowed to stand and
cool. The boiling drives off dissolved air and also removes some
minerals.
Try putting just a pinch of sulfite in the water before mixing the
Metol, for a liter about 5 grams is right. The Sulfite tends to absorb
any dissolved oxygen but is not present in sufficient concentration to
keep the Metol from dissolving.
In general large volumes of developer last longer than smaller ones
because the surface area to volume is smaller.
I also suggest mixing the buffered version of D-76 rather than the
original formula. The original tends to increase in activity over time,
the buffered version does not.
Kodak D-76d Buffered Fine Grain Developer
Water (at 125F or 52C) 750.0 ml
Metol 2.0 grams
Sodium Sulfite, dessicated 100.0 grams
Hydroquinone 5.0 grams
Borax, granular 8.0 grams
Boric Acid, crystaline 8.0 grams
Water to make 1.0 liter
This formula has the same activity as fresh D-76 and maintains that
activity during storage.
--
Richard Knoppow
Los Angeles, CA, USA
dick...@ix.netcom.com
narke
answer some of my questions.
1) about the 1:1 question
2) There is no packaged D-76 for sale in my city, so I have to mix it
at home. For this kind of solution, what's the shelf lift?
Regards.
John
>Thank you very much for the advice and the D-76d formula. But you dont
>answer some of my questions.
>
>1) about the 1:1 question
I reviewed your original post and didn't see any question
about the 1:1 dilution.
>2) There is no packaged D-76 for sale in my city, so I have to mix it
>at home. For this kind of solution, what's the shelf lift?
This begs the question, why mix developers much more than
prior-to-use ? Theoretically D-76d is probably good in a full bottle
for a year and 3 months in a half full bottle but there are many
factors that play into that. Factors such as :
1) Do you use distilled water
2) Will the developer be stored in a cool dark location
3) Are you using glass bottles
4) Will you be using a surfactant ?
In the FWIW category I would recommend D76H mixed immediately
before use.
Kodak's D-76 H
Water @ 125F - 750ml
Elon - 2.0 g
Sod. Sulfite - 100.0g
Borax (gran.) - 2.0g
Water to make 750ml
Regards,
John S. Douglas, Photographer - http://www.puresilver.org
dan.c...@att.net
> In the FWIW category I would recommend D76H mixed immediately
> before use. Kodak's D-76 H
>
> Water @ 125F - 750ml
> Elon - 2.0 g
> Sod. Sulfite - 100.0g
> Borax (gran.) - 2.0g
> Water to make 750ml
>
>
I've always thought that a good one, D-76 without hydroquinone.
May as well scratch the borax. It's only there because of
H. quinone's OH radical formation.
Minus the borax leaves a weak D23. He might do better mixing
up a one fifth liter of D23 and use it 1:2, as you say, at time
of use. I was using an 8 - 80 gram, metol - sulfite D23; a
one eighth batch for one roll.
Has he a good scale? Helps with small batches. Dan
Richard Knoppow
"narke" <ste...@lczmsoft.com> wrote in message
news:1112000730.4...@f14g2000cwb.googlegroups.com...
I've found that to be very conservative. The Kodak Labs
paper which described the actvity rise problem and gave the
buffered formula shows tests of D-76. These show that over
about a 2 month period the activity rose to the point where
development time for a given contrast fell to a bit more
than half of the time required by fresh developer. The
buffered developer showed no rise. If you use the developer
quickly there is no problem with the original but, since you
are mixing your own, and since you have boric acid for
fixing baths anyway, why not use the better formula.
--
---
narke
about the 1:1 dilution.
Sorry. I want to ask: How to get a 1:1 solution. Follow the D-76
original formula, and, every time when prepare to dev, get the
original solution and add the same volume water to make?
BTW: I also make sure what dose the 'cold water to make' precisely
mean. i.e, in the D-76 original formula how many water used? 1 liter
or 1 + 0.75 liter?
Thanks.
-
narke
narke
Thanks. I like to follow your advice and go to D-76d. Two question
about it,
1) while d-76d can be substitute for d-76, can d-76d 1:1 be
substitute for d-76 1:1
2) What's the different in the develop time between d-76d and d-76 (or
d-76d 1:1 and d-76 1:1)
Thanks
-
narke
Richard Knoppow
Sorry, I see I mis-read the question. D-76 diluted 1:1 does not last
long. Kodak recommends diluting just before use and discarding the
developer after use.
Home mixed stock should have the same shelf life as the package
form, Kodak states 6 monthes in a closed, capped, bottle. My experience
is that it lasts longer.
Richard Knoppow
fresh developer the times are exactly the same for both
whether stock or diluted. The advantage of D-76d is that its
activity is stable with time. If you are going to use up the
developer within a few days it will make no difference which
you use.
Since you are mixing your own you can mix the equivalent
of diluted D-76 but with optimum sulfite. This would be:
Water 750.0 ml
Metol 1.0 gram
Sodium sulfite, dessicated 85.0 grams
Hydroquinone 2.5 grams
Water to make 1.0 liter
This should have about the same activity as diluted regular
D-76 but will have very slightly finer grain.
Keith Tapscott
"Richard Knoppow" <dick...@ix.netcom.com> wrote in message
news:O3q3e.883$N13...@newsread3.news.pas.earthlink.net...
out the Borax is an interesting theory, but have you personally tested this
formula? If so, how do the dev times compare with regular D-76/ID11 when
diluted 1:1?