Reusing B&W Darkroom chemicals
Jeffrey L. Jue
I am using D-76, Stop Bath, and RapidFix--all from Kodak. What are
their usage limits as far as reusing. I have gotten from different
sources to recycle certain things and not others. They seem to say
different things. Help!
Oh yeah, I am using TMax 400 & 3200.
Jeffrey Jue
http://www2.netdoor.com/~guardian
guar...@netdoor.com
Richard Knoppow
See the Kodak Black and White Dataguide for charts showing shelf
life and capacities of their chemicals. Stop bath isn't worth saving.
This info may also be on the Kodak web site at www.kodak.com
---
Richard Knoppow
Los Angeles, Ca.
dick...@ix.netcom.com
LJ Powell
guar...@netdoor.com (Jeffrey L. Jue) wrote:
>I am using D-76, Stop Bath, and RapidFix--all from Kodak. What are
>their usage limits as far as reusing. I have gotten from different
>sources to recycle certain things and not others. They seem to say
>different things. Help!
>Oh yeah, I am using TMax 400 & 3200.
It's different strokes for different folks, but here's what I do -
developer - use it one-shot. It's not all that expensive, and
one-shot use gives me the ability to have control over developing.
stop - for film, I make up a weak acid stop solution using a little
28% acetic acid and water - enough acid so that the pH is lower than
7, but not a full-strength stop by any means. Again, one-shot and
dump it. Note that many people advocate using straight water as a
stop with film.
fix - this I reuse until it's exhausted. The bottle suggests an
exhaustion rate, but I never run more that half the manufacturer's
recommendations through the fix. T-max exhausts fix must faster than
other emulsions, so one clue is fixing time. Another is to use Edwal
Hypo-Chek to determine when it's dead.
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Louie Powell
<LJPo...@ix.netcom.com>
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
scrap...@aol.com
Only reuse your fixer. It is possible to replenish your d-76 but not
worth it. It is impossible to have consistency when you replenish. As
far as stop bath goes, only use it once. If you have more questions, I am
a student at Brooks Institute of Photography. E-mail me at
scrap...@aol.com. I'll be happy to answer any of your questions.
-Scrapy
Scott Lavender
Do you feel that a stop bath is absolutly neccessary? I have used a
water bath only between the developer and the fixer for years. It seems
that the acid stop bath can shorten the life of the fixer.
Any thoughts?
--
Scott T. Lavender / S2 Systems, Inc. / Atlanta, Ga
Email: Scott_L...@stratus.com
Jimmy Tung
Scott Lavender (Scott_L...@stratus.com) wrote:
: scrap...@aol.com wrote:
: >
: > Only reuse your fixer. It is possible to replenish your d-76 but not
: > worth it. It is impossible to have consistency when you replenish. As
: > far as stop bath goes, only use it once. If you have more questions, I am
: > a student at Brooks Institute of Photography. E-mail me at
: > scrap...@aol.com. I'll be happy to answer any of your questions.
: > -Scrapy
:
: Do you feel that a stop bath is absolutly neccessary? I have used a
: water bath only between the developer and the fixer for years. It seems
: that the acid stop bath can shorten the life of the fixer.
:
: Any thoughts?
First, whatever works, ultimately works. There are lots of opinions out
here.... :-)
Actually, the use of stop bath should *prolong* the life of the fixer.
Mostly because you're using a marginal amount of fixer to adjust the pH
down after the alkaline developer (the water bath wash will most likely
*not* result in a pH neutral solution). The water wash effectively
removes the developer as well as an acid (stop bath) wash. In principle,
the stop bath will immediately quench the development process, while a
freshwater rinse will "only" slow it down (I haven't heard this discussed
in anything but theoretical terms, eg.... my negs have an extra glow b/c
of the compensating effect of a water rinse.... sounds like something
Fred Picker would say :-)).
That said, I'd pay attention to the fixer capacity also (provided you're
relatively concerned about long-term stability versus archival versus need
the d*mn neg since its 20 minutes before deadline and I don't care what
happens afterwards...). There's lots of interesting chemical equilibria
being set up in the solution as you use it; the practical offshoot is that
fresh fixer, slightly used fixer, and nearly-depleted fixer are all very
different critters (and the falloff in activity is NOT linear). The
oxidation products and the normal reaction products (just like developer)
have an inhibiting effect on the fixer activity.
At least, I think that was part of the line which supported a two-bath fixer
(in paper) procedure.
As I understand it, Ilford's archival standard is now 1 minute in rapid
fixer (30 sec, if agitation and wetting is good), followed by lots (well
20 minutes) of washing to get the fixer back *out* (excess fixer being the
problem rather than unreacted silver).
Anyway, hope this was of some interest. I'd welcome any comments. I
don't claim to be a darkroom wizard, but chemistry (the science rather
than the photographic noun) is a bit of an interest of mine.
jt
spectrum
Scott Lavender wrote:
>
> scrap...@aol.com wrote:
> >
> > Only reuse your fixer. It is possible to replenish your d-76 but not
> > worth it. It is impossible to have consistency when you replenish. As
> > far as stop bath goes, only use it once. If you have more questions, I am
> > a student at Brooks Institute of Photography. E-mail me at
> > scrap...@aol.com. I'll be happy to answer any of your questions.
> > -Scrapy
>
> Do you feel that a stop bath is absolutly neccessary? I have used a
> water bath only between the developer and the fixer for years. It seems
> that the acid stop bath can shorten the life of the fixer.
>
> Any thoughts?
>
An acid stop bath will not harm a fixing bath. I is just chemicly
impossible. The older fixer formulas included a acidifier to negate any
developer alklinity still in the paper. This also hardened the emulsion
and is not really utilized today except perhaps in the photo labs that
process RC on a machine.
Richard Knoppow
spectrum <spec...@cybercomm.net> wrote:
In fact, one main purpose of using an acid stop bath is to _extend_
the life of the fixing bath. It also prevents staining caused by
carry-over of developer into the fixing bath.
BTW, I disagree with the original poster that it is impossible to
get consistent results with a replenished developer. It just depends
on how carful you are with replenising it. All motion picture film is
developed by machine with constantly replenished developer systems and
the required consistency is much higher than in any still photography.
For those who do not devlop large amounts of film the one-shot
method is best but for large volume users replenished systems work
very well for both B&W and color.
Ron Frank
spectrum wrote:
>
> Scott Lavender wrote:
> >
> > Do you feel that a stop bath is absolutly neccessary? I have used a
> > water bath only between the developer and the fixer for years. It seems
> > that the acid stop bath can shorten the life of the fixer.
> >
> > Any thoughts?
> >
> > --
> > Scott T. Lavender / S2 Systems, Inc. / Atlanta, Ga
> > Email: Scott_L...@stratus.com
>
I also do NOT use a stop bath except when processing infra-red. It may not be
necessay for infra-red, but I have it handy for printing anyway, and it is
recommended so ......
I've not had any problem with skipping the stop bath step. I fill the tank up
five times with fresh water within a few degrees of the developer. Stop bath is
real cheap however, and I do not believe that it wears on fixer.
Ron
Adam
I've always been told that the stop bath was supposed to save the fixer, not
destroy it.
Adam
Acomjean
The News room at the UMass Daily Collegian used to use tmax developer
twice to save $. (I've graduated and don't know what they do now) Its
used once then poured into an airtight container.. Used a second time and
disguarded. I'll be damed if I could tell the difference.... (don't try
to push film with used developer though).
-Aram