Ilford Abandons Archival Print Fix/Wash?

I just finished reading Ilford's Rapid Fix PDF. Rapid fix
dilutions recommended are 1:4 or 1:9. Fix times are still a short
1 min.; no specific paper mentioned. Just from reading I'd suppose
any paper will fix in that time.

The 'old' post fix routine was 5 min wash, 10 min. their brand
hca, then a second 5 min. wash. The new routine is; 5, 10, 20 min..

Their quick 30, and later 60 secs. in film strength fixer and
post fix 5, 10, 5 min. Archival routine was a bit of a revolution
on it's introduction.

AND BTW, IDNR ( I do not recall ) any mention of putting 40 prints
through 1 liter of working strength. In fact 10 8x10s are mentioned
for Archival results. Ilford WAS upping that 10 to 40 when THEIR
brand of HCA was used; a fact that Dr. M. Gudzinowicz had
trouble swallowing. Dan

Dan Quinn wrote:

I just finished reading Ilford's Rapid Fix PDF. Rapid fix
dilutions recommended are 1:4 or 1:9. Fix times are still a short
1 min.; no specific paper mentioned. Just from reading I'd suppose
any paper will fix in that time.

I use rapid fix at 1:3 (1+3) and have done so for years.

A simple test will tell you. Take a strip of the unexposed
paper and mark it in equal segments using a pen or pencil.
Dip each segment successively in film strength for 5 seconds,
ending at about 45 seconds. For 1:7 or 1:9 or whatever you
use, increase that to maybe 15 seconds ending at 3 minutes or
so. Turn on the room lights for 1-2 seconds, then develop the
strip. You'll easily see just how long it takes to completely
fix. Double that time.

Film strength fix does in fact fix papers in less than 30
seconds. Henry states some exceptions may be Kodak papers.

Ilford's archival method works, though I've never seen any reason
to hypoclear for 10 minutes. The whole point of the short fix
is to limit the amount (via time) of residual thiosulfate ions
that bond to the paper, so it's the fix time, not the hypoclear
time, that accomplishes this. I see no advantage to extending the
HCA time, ubless someone can prove that a 10 minute time produces
a more efficacious ion exchange than the standard 3 minutes. I've
always used KHCA for 3-5 minutes, then washed for a minimum of 20
min. up to an hour. My HT-2 tests show little difference, if any,
in the stains I get at 20 min. vs. 60 minutes. I consider my prints
clean at 20 but usually wash for about 40 minutes.

When I don't use HCA wash times are longer than 20 minutes, but
using 1:3 fix for 1 minute I've found virtually no difference
in HT-2 stains between HCA prints and non HCA prints at 60
wash minutes.


The 'old' post fix routine was 5 min wash, 10 min. their brand
hca, then a second 5 min. wash. The new routine is; 5, 10, 20 min..

Their quick 30, and later 60 secs. in film strength fixer and
post fix 5, 10, 5 min. Archival routine was a bit of a revolution
on it's introduction.

AND BTW, IDNR ( I do not recall ) any mention of putting 40 prints
through 1 liter of working strength. In fact 10 8x10s are mentioned
for Archival results. Ilford WAS upping that 10 to 40 when THEIR
brand of HCA was used; a fact that Dr. M. Gudzinowicz had
trouble swallowing. Dan

"Dan Quinn" wrote in message
om...
I just finished reading Ilford's Rapid Fix PDF. Rapid fix
dilutions recommended are 1:4 or 1:9. Fix times are still
a short
1 min.; no specific paper mentioned. Just from reading I'd
suppose
any paper will fix in that time.

The 'old' post fix routine was 5 min wash, 10 min. their
brand
hca, then a second 5 min. wash. The new routine is; 5, 10,
20 min..

Their quick 30, and later 60 secs. in film strength fixer
and
post fix 5, 10, 5 min. Archival routine was a bit of a
revolution
on it's introduction.

AND BTW, IDNR ( I do not recall ) any mention of putting
40 prints
through 1 liter of working strength. In fact 10 8x10s are
mentioned
for Archival results. Ilford WAS upping that 10 to 40 when
THEIR
brand of HCA was used; a fact that Dr. M. Gudzinowicz had
trouble swallowing.
Dan

There is some controversey about the capacity of ammonium
thiosufate fixers. For sodium thiosulfate there is no
question of the severe limit of a single bath to fix
completely. A two bath system will extend the capacity from
four to ten times that of a single bath. Ryuji Suzuki, a
chemist, says that research by G.I.P.Levenson indicates that
ammonium thiosulfate fixer is much more tollerant of
dissolved silver than sodium thiosulfate, to the point were
a single bath is acceptable. I have not read this research
so can't comment on it, but would, at this point, continue
to use a two bath system.
Sulfite wash aid does make some fixer reaction products,
which are otherwise tightly bound to the image silver and
gelatin, wash out. This binding effect is partly due to
incomplete conversion to a soluble form. Kodak mentions in
the research paper for KHCA that it extends the effective
life of fixing baths by making othewise insoluble reaction
products soluble.
I am not sure what is in Ilford's wash aid but think it
is very similar to Kodak's. Kodak Hypo Clearing Agent is a
sulfite solution buffered to neutral pH with bisulfite. It
also has two sequestering agents added, EDTA tetrasodium
salt and sodium citrate. These tend to prevent precipitation
of carbonates on the surface of the film or paper when the
wash aid is re-used. The neutral pH is important. It
releases thiosulfate and fixer reaction products bound to
the gelatin by the aluminum sulfate in hardening fixing
baths. It also raises the pH of the gelatin above its
isoelectric point where binding of reaction products and
thiosulfate bound to the gelatin by the electric charges in
the gelatin. As a result wash times are very much
accelerated and the retarding effect on washing of white
alum hardener is eliminated. Nonetheless, thiosulfate held
in the support of fiber paper is held by frictional forces
rather than chemical or electrical binding so they take a
long time to wash out even with the ion exchange effect of
the sulfite wash aid.
Ilford's original idea was that if fixing time was short
enough the thiosulfate would not penetrate into the paper
enough to require long wash times. There is some
controversey about this and about whether complete fixig can
be accomplished in the short time necessary to prevent
adsorption of the thiosulfate. This is ideally no longer
than 30 seconds but Ilford found that few papers will fix
out in this time even with concentrated ammonium thiosulfate
fixer. Some papers, notably some Kodak papers, take as long
as two minutes to fix out making the whole procedure
useless.
The Kodak research on KHCA found that maximum effect was
obtained in four minutes regardless of the materialThe curve
becomes asymptotic after this with little further effect.
Actually, nearly complete wash aid effect is achieved in
three minutes. Kodak recommends washing double weight paper
for 20minutes after a three minute treatment in KHCA. This
washes both thiosulfates and reaction products down to an
archival level and also washes enough to prevent staining in
toning processes.


--
---
Richard Knoppow
Los Angeles, CA, USA

"Dan Quinn" wrote in message
om...
I just finished reading Ilford's Rapid Fix PDF. Rapid fix
dilutions recommended are 1:4 or 1:9. Fix times are still
a short
1 min.; no specific paper mentioned. Just from reading I'd
suppose
any paper will fix in that time.

The 'old' post fix routine was 5 min wash, 10 min. their
brand
hca, then a second 5 min. wash. The new routine is; 5, 10,
20 min..

Their quick 30, and later 60 secs. in film strength fixer
and
post fix 5, 10, 5 min. Archival routine was a bit of a
revolution
on it's introduction.

AND BTW, IDNR ( I do not recall ) any mention of putting
40 prints
through 1 liter of working strength. In fact 10 8x10s are
mentioned
for Archival results. Ilford WAS upping that 10 to 40 when
THEIR
brand of HCA was used; a fact that Dr. M. Gudzinowicz had
trouble swallowing.
Dan

There is some controversey about the capacity of ammonium
thiosufate fixers. For sodium thiosulfate there is no
question of the severe limit of a single bath to fix
completely. A two bath system will extend the capacity from
four to ten times that of a single bath. Ryuji Suzuki, a
chemist, says that research by G.I.P.Levenson indicates that
ammonium thiosulfate fixer is much more tollerant of
dissolved silver than sodium thiosulfate, to the point were
a single bath is acceptable. I have not read this research
so can't comment on it, but would, at this point, continue
to use a two bath system.
Sulfite wash aid does make some fixer reaction products,
which are otherwise tightly bound to the image silver and
gelatin, wash out. This binding effect is partly due to
incomplete conversion to a soluble form. Kodak mentions in
the research paper for KHCA that it extends the effective
life of fixing baths by making othewise insoluble reaction
products soluble.
I am not sure what is in Ilford's wash aid but think it
is very similar to Kodak's. Kodak Hypo Clearing Agent is a
sulfite solution buffered to neutral pH with bisulfite. It
also has two sequestering agents added, EDTA tetrasodium
salt and sodium citrate. These tend to prevent precipitation
of carbonates on the surface of the film or paper when the
wash aid is re-used. The neutral pH is important. It
releases thiosulfate and fixer reaction products bound to
the gelatin by the aluminum sulfate in hardening fixing
baths. It also raises the pH of the gelatin above its
isoelectric point where binding of reaction products and
thiosulfate bound to the gelatin by the electric charges in
the gelatin. As a result wash times are very much
accelerated and the retarding effect on washing of white
alum hardener is eliminated. Nonetheless, thiosulfate held
in the support of fiber paper is held by frictional forces
rather than chemical or electrical binding so they take a
long time to wash out even with the ion exchange effect of
the sulfite wash aid.
Ilford's original idea was that if fixing time was short
enough the thiosulfate would not penetrate into the paper
enough to require long wash times. There is some
controversey about this and about whether complete fixig can
be accomplished in the short time necessary to prevent
adsorption of the thiosulfate. This is ideally no longer
than 30 seconds but Ilford found that few papers will fix
out in this time even with concentrated ammonium thiosulfate
fixer. Some papers, notably some Kodak papers, take as long
as two minutes to fix out making the whole procedure
useless.
The Kodak research on KHCA found that maximum effect was
obtained in four minutes regardless of the materialThe curve
becomes asymptotic after this with little further effect.
Actually, nearly complete wash aid effect is achieved in
three minutes. Kodak recommends washing double weight paper
for 20minutes after a three minute treatment in KHCA. This
washes both thiosulfates and reaction products down to an
archival level and also washes enough to prevent staining in
toning processes.


--
---
Richard Knoppow
Los Angeles, CA, USA