Re: Liquid Emulsion

From: Ryuji Suzuki ^lt;>
Date: 06/04/04-04:17:44 PM Z
Message-id: <>

That is caused by insufficient hardening of the emulsion.

The procedure I found to work the best and what I use is to add small
amount of dilute, 2.5% glutaraldehyde to the emulsion immediately
before coating in the dish while stirring well. Then coat, dry, expose
and process normally. Kate Mahoney has used formaldehyde in place of
glutaraldehyde with good success, but glutaraldehyde is a superior
hardener with less adverse effects to the photographic properties of
the emulsion.

Alternatives are to harden emulsion in a separate bath before
developer, use hardening developer, hardening stop bath, or hardening
fixing bath. Emulsion swells a lot in developer and stop bath, so it
makes sense to harden before developer. However, I do not recommend to
use pre-developer hardening bath because of potential health hazard.
Adding hardener in emulsion is much safer.

You could try hardening fix, but alum hardener in fixing bath is less
effective, and this approach would require longer washing and/or use
of wash aid, and it is not the best option.

The problem is that glutaraldehyde seems rather difficult to buy,
especially in dilute solution suitable for emulsion hardening. I have
a list of other chemicals that can be used, but these are much more
limited distribution and also more expensive.

Ryuji Suzuki
"You have to realize that junk is not the problem in and of itself.
Junk is the symptom, not the problem."
(Bob Dylan 1971; source: No Direction Home by Robert Shelton)
Received on Fri Jun 4 16:18:17 2004

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