[pure-silver] Re: Cleaning a Drum Dryer
- From: Bogdan Karasek <bkarasek@xxxxxxxxxxxx>
- To: pure-silver@xxxxxxxxxxxxx
- Date: Wed, 04 Apr 2007 00:14:06 -0400
Hi,
Just to add what Kodak has to say on the matter. Both Sepia Toner and
Sepia Toner II warm toner give the same directive after the prints have
been toned and washed for 30 secs.
"Harden the print for 2-5 minutes in a hardening bath composed of 1 part
KODAK liquid hardener in 13 parts of water or 2 parts KODAK stock
hardener F-5a in 16 parts of Water
Wash Fiber base for 30 minutes at 18-21°C * 65-70°F (4 min. for RC)"
Cheers,
Bogdan
Richard Knoppow wrote:
----- Original Message ----- From: "john stockdale" <j.sto@xxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Tuesday, April 03, 2007 7:07 PM
Subject: [pure-silver] Re: Cleaning a Drum Dryer
I dry fibre prints in a flat bed dryer with the emulsion facing the cloth,
i.e. not ferrotyping. Even without toning, I've noticed miniscule fibres
from the cloth well and truly stuck to the emulsion. I use the usual
sulphite/bisulphite wash aid. Am I correct in assuming that a hardening
bath after the wash aid but before the main washing would make the fibres
less likely to adhere?
John Stockdale
The buffering of the Sulfite-Bisulfate wash aid (Kodak Hypo Clearing
Agent) is supposed to adjust the pH of the emulsion to a point where the
hardening of the usual white alum hardener is still effective but where
the mordanting effect the hardener has for the thiosulfate is broken.
Using an after hardener would undo part of the effect of the wash aid. I
think its better to use either a hardening fixing bath or an auxilliary
hardener before the wash aid treatment.
The usual hardening fixing bath, especially "rapid" fixer, will fix
out the paper before the hardener has time to work fully. This is one of
the reasons for the very long fixing times specified in old books (along
with the assumption that the fixer would be partially exausted).
Since even hardened gelatin is fairly soft I suspect the real answer
is to use some other method of drying or to replace the aprons (if
possible) with new ones that don't leave fiber particles.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
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--
________________________________________________________________
Bogdan Karasek
Montréal, Québec bogdan@xxxxxxxxxxxxxxx
Canada www.bogdanphoto.com
"I photograph my reality"
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