From: John Roseborough (jroseborough@prodigy.net)
Date: 07/15/01-09:46:53 AM Z
David,
The metaborate is the alkaline component of the developer. It controls the
developer activity. Used in the presoak, it also dissolves the antihalation
backing on some films. The after bath, either spent developer or
metaborate, helps with the formation of the stain. (If I have misspoken
someone will correct me.)
When using the print drums I have also experienced uneven development at the
ridges in those drums. The expert drums solve the problem. The 11x14
Expert drum is nothing more than the 11x14 print drum with an insert that
has dimples on it that hold the film above the insert allowing chemistry to
flow under the back of the film. It works but 1 sheet at a time is a drag.
my .02 worth
John Roseborough
Pyro 4 Hire
----- Original Message -----
From: Nash Computer Technology <nashcom@btinternet.com>
To: Alt Photo <alt-photo-process-l@sask.usask.ca>
Sent: Sunday, July 15, 2001 5:55 AM
Subject: Sodium Metaborate
> Hi
>
> I'm curious about what Sodium Metaborate does with regard to Pyro
> development.
>
> I've been using Rollo Pyro with 5x4" negs in a Jobo CPE2 and 5x4" drum.
> However, I now need to process 10x8" negs, and have been having a few
> problems.
>
> I thought I would try a 10x8" print drum on my Jobo (to save the expense
of
> buying an Expert drum and/or a CPA/CPP processor). The first attempt
> produced negs where the anti-halation layer wasn't sufficently cleared. I
> re-fixed in a tray and rinsed, and it got rid of the marks, but I wasn't
too
> happy about the results.
>
> The next time, I removed the drum from the processor about one minute into
> the initial sodium metaborate bath and also one minute into the
development,
> and rocked the drum laterally whilst turning it. By this I hoped to
acheive
> chemicals getting behind the film with a bit of agitation, and sure
enough -
> no anti-halation layer was left. However, there seemed to be uneven
> development around the areas of the ribs in the print drum - there are a
> couple of noticeable lines from top to bottom on my prints.
>
> The next thing I thought about trying was a tray pre-soak, but am not sure
> whether to do this in a tray of just water before transferring the film to
> the drum and to the first sodium metaborate bath, or whether to do the
> sodium metaborate bath in a tray, and go straight into development when
the
> film is transferred to the drum. From this, I wonder if the time in the
> sodium metaborate or water is critical, or whether I could pre-soak each
> film separately.
>
> If this doesn't work, I'll need to try tray processing with PMK Pyro, but
I
> suspect that could be fraught - I would also have to travel to a darkroom
as
> I don't have the facilities for multiple tray processing at home.
>
>
> David Nash
>
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