[pure-silver] Re: Ilford 2150 machine emits Ammonia??
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Sun, 20 Aug 2006 13:57:43 -0700
----- Original Message -----
From: "Edward C. Zimmermann" <edz@xxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Sunday, August 20, 2006 1:45 PM
Subject: [pure-silver] Re: Ilford 2150 machine emits
Ammonia??
Quoting Barry Brinkman <bbrinkman@xxxxxxx>:
I have a Kreonite processing machine and ammonia is
produced when
the developer and fixer are inadvertantly mixed together.
Once that
Rapid fixers are based upon ammonium thiosulfate.
Developers tend to
be alkaline. When the pH (adding in some developer) is
brought to alkaline it
starts to give off some ammonia. Solution? Use a buffered
acid fixer.. :-)
problem is fixed the smell usually is gone by the next
day.
--
--
Edward C. Zimmermann, Basis Systeme netzwerk, Munich
Office Leo (R&D):
Leopoldstrasse 53-55, D-80802 Munich,
Federal Republic of Germany
http://www.nonmonotonic.net
It might be useful to contact Ilford to find out if they
can still supply instructions for the machine.
Nearly all standard fixing baths are buffered and can
withstand quite a bit of carried over developer. There is
usually also a relatively large amount of sulfite to
counteract the tendency of the acid to decompose the
thiosulfate. Sodium thiousulfate fixing baths tend to emmit
Sulfur Dioxide gas which has a "sharp" odor and is very
irritating. Hydrogen Sulfide (rotten egges) indicates more
decomposition. Added to this will be some Ammonia odor if an
Ammonium Thiosulfate bath is used.
I suspect the machine is not really clean. A cleaner made
from Sulfuric Acid and Potassium Dichromate will remove
silver and some other contaminants but will not remove
Silver Sulfide deposits. Kodak has a small data sheet on its
web site about removing these deposits and also sponge
silver. Sometimes it takes scrubbing.
If this machine was out of service for any length of time
before you got it there is likely to be crystalized
chemistry in it that will not come out with routine
cleaning. Again, check with Ilford about suggestions on
cleaning and preferred chemistry.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
=============================================================================================================
To unsubscribe from this list, go to 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.
Other related posts:
