Mysterious Black Silt, or Residue in Fixer Tray is also Staining Prints

[tipscommissar]

Hello,

I have a question here that has even stumped the tech people at Kodak.
What we have (we are a small high school darkroom) is a cloudy black
silt in the fixer that leaves sooty stains on the prints. I am using
the recommended dilution for all chemicals. The developer is Dektol,
and we're using Kodak indicator stop. I have tried three different
brands of resin-coated papers, and the results are the same. We use a
two minute fixing time.

Yesterday I tried switching to a non-hardening fixer (Kodak solution
A) and the results were lessened but the same. So it's not like we're
talking about a bad batch of fix and/or a contaminated fix jug.

Here is another thing: we have a separate tray of non-hardening fix
for the advanced students who use fiber paper. There has been no
staining of the fiber paper, and there's no silt in that particular
tray.

I can't understand what is going on here. I have used the same
chemistry dilutions in the same darkroom for ten years and now this
happens.

I should also add that the same silt is coating the inside of our film
fix container but is not staining the film. And I know that this silt
is probably silver; the vital question are what is happening with the
fixer and the RC paper and how do we stop it from staining more of our
prints.

Thanks for helping,

Jerry

[Nicholas O. Lindan]

"tipscommissar" <tipsco...@yahoo.com> wrote

> cloudy black silt in the fixer that leaves sooty stains on the prints.

I have had that happen in a Nalgene bottle that held working fix. After
a while the bottle formed a grey coating on the inside that would
precipitate
the silver from the fix.

The fix (pardon the pun) was to throw out the bottle. There wasn't any
cleaning or bleaching operation that had any effect on the bottle's
precipitative powers.

I would try using brand new jugs/bottles, new trays and new tongs.

--
Nicholas O. Lindan, Cleveland, Ohio
Darkroom Automation: F-Stop Timers, Enlarging Meters
http://www.darkroomautomation.com/da-main.htm
n o lindan at ix dot netcom dot com

[Peter]

On Sep 21, 7:26 pm, "Nicholas O. Lindan" <s...@sig.com> wrote:
> "tipscommissar" <tipscommis...@yahoo.com> wrote

>
> > cloudy black silt in the fixer that leaves sooty stains on the prints.
>
> I have had that happen in a Nalgene bottle that held working fix.  After
> a while the bottle formed a grey coating on the inside that would
> precipitate
> the silver from the fix.
>
> The fix (pardon the pun) was to throw out the bottle.  There wasn't any
> cleaning or bleaching operation that had any effect on the bottle's
> precipitative powers.
>
> I would try using brand new jugs/bottles, new trays and new tongs.
>
> --
> Nicholas O. Lindan, Cleveland, Ohio

> Darkroom Automation: F-Stop Timers, Enlarging Metershttp://www.darkroomautomation.com/da-main.htm

> n o lindan at ix dot netcom dot com

I've seen something similar (rarely) where hypo had been stored and it
encountered significant temperature changes; also around some metal
tongs.

[Lawrence Akutagawa]

"Nicholas O. Lindan" <s...@sig.com> wrote in message
news:DMednfvGzYw9liXX...@earthlink.com...

> "tipscommissar" <tipsco...@yahoo.com> wrote
>
>> cloudy black silt in the fixer that leaves sooty stains on the prints.
>
> I have had that happen in a Nalgene bottle that held working fix. After
> a while the bottle formed a grey coating on the inside that would
> precipitate
> the silver from the fix.
>
> The fix (pardon the pun) was to throw out the bottle. There wasn't any
> cleaning or bleaching operation that had any effect on the bottle's
> precipitative powers.
>
> I would try using brand new jugs/bottles, new trays and new tongs.
>

Soak the offending trays/bottles in a plain old ordinary Clorox dilution
with water in a well ventilated area. Stand back from the resulting fumes.

How old is this fixer? If fresh, are you using distilled or at least
ionized water?