From: Gordon J. Holtslander (holtsg@duke.usask.ca)
Date: 10/07/02-12:02:26 AM Z
Here's a bleaching formula from photographic facts and formula's, under
the stain removing section, for bleaching and redevoloping a stained
negative (to remove the stain I assume)
It recomends treating the film in a formalin hardener for two or three
minutes
from the book:
Formalin hardener (Kodak sh-1)
formalin, 37% formaldehyde solution 10cc
Sodium carbonate 5 g
water to make 1000cc
Wash for five minutes and the bleach in:
Stain remover (Kodakk s-6)
stock soln A
pottasiun permanganate 5.3 g
water to make 1000 cc
stock soln B
sodiun chloride (table salt) 75.0 g
Sulfuric acid C.P. (concentrated) 16 cc
water to make 1000 cc
Use equal parts of solutions A and B, which should be mixed only at the
time of use, as they keep well in seperate solutions but not in
combination. Be sure that the potassium permangante is thoroughly
dissolved as any particles of it out of solution will cause blemishes on
the negative.
Bleach for three to four mintues and the remove the brown stain by first
rinsing the bleached film in water and placing it in a 1 percent solution
of sodium bisulfite. Wash for three of four minutes/
I assume you don't want to do this part, it goes on to say...
/and expose to a strong light until the white image turns purple.
Redevelop in a non-staining developer suach as amidol without the use of
bromide.
This book also list a variety of bleaches used with bromoil, but its
getting late :) Let me know if you want these.
Gord
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Gordon J. Holtslander Dept. of Biology
holtsg@duke.usask.ca 112 Science Place
http://duke.usask.ca/~holtsg University of Saskatchewan
Tel (306) 966-4433 Saskatoon, Saskatchewan
Fax (306) 966-4461 Canada S7N 5E2
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