From: Brian Ellis (bellis60@earthlink.net)
Date: 06/25/01-06:02:32 AM Z
I'm curious about the conflict between the statement here, to the effect
that an acid stop bath or fix will prevent the pyro stain from forming, and
the instructions n Gordon Hutchings' book to the effect that an acid stop
bath is fine with normal development. Based on Hutchings' book, when using
PMK pyro I've used an acid stop bath and fix and haven't noticed any
problems with a stain forming as long as the film is immersed in the used
developer for two minutes and washed for 20-30 minutes. Would I get a
"better" stain if I switched to water in place of the stop bath and to a
non-acidic fix? If so, in what way would it be "better?"
I know that I could switch to a non-acidic fix and eliminate the used
developer step but that step isn't particularly difficult or time consuming
and I'd rather continue with it than add yet another chemical (non-acidic
fix) to my darkroom unless there's a good reason to do so.
----- Original Message -----
From: "Carl Weese" <cweese@earthlink.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Monday, June 25, 2001 6:41 AM
Subject: Re: Pyro and staining
> Pyro stain is allergic to acid conditions -- an acid stop bath or fix will
> prevent stain formation on regular silver gelatin film...
>
> >
> > From what I have read the pyro will not oxidize very rapidly in an
acidic
> > solution. How much time do I have to use it before it starts to degrade?
The
> > reason I ask is that I am adding Pyro to each "shot" of developer vs
mixing
> > up a batch. Batching is more convenient.
> >
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