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washing negatives - Does the fixer leach out?


PS: Levinson or Levenson? Depends upon whom you
are reading, Ron or Bill.
 
PS: Levinson or Levenson? Depends upon whom you
are reading, Ron or Bill.

I found misspelling in your post; both Ron Mowrey and Bill Troop are in my ignore list and I don't read their posts. If they repeat misspelling of Levenson, you might want to remind them and also question their knowledge of his work.
 
There are both a G. Levinson and a G. Levenson who are cited in photographic textbooks. G. Levinson is the less prominent of the two. G. I. P. Levenson has been cited to assist in separating the two.

I have not checked my posts, but I'm sorry if I misspelled his last name as Levinson in error in this context. It is correctly G. I. P. Levenson. Please excuse the error, but under the circumstances with the great similarity, I hope you excuse the 'crossover'. It was certainly unintentional.

PE
 
the book I originally wrote was about five times longer (no exaggeration) and would have been unpublishable in the late 90s. My question is, what is publishable today?

Bill, if you publish it, I will buy it! Website, PDF, paper, whatever. The sheer delight of solid and synthetized information is a constant joy. I wish I'll have enough spare money some day to buy the updated version of Mr Haist's book, but for now I make do with a library copy.
 
Michel;

The updated version was never published. Work was interrupted as noted above. C'est dommage.

PE
 
"I found misspelling in your post; both Ron Mowrey and Bill Troop are in my ignore list and I don't read their posts."

"You don't seem to know how rude you are." (Goethe) (who also used variant spellings!)

Re the Ilford system, Roger, I don't have the Kodak table handy but it's buried in Haist and runs something like this. In a continuous stream of water wash, for film processed in an alkaline fixer, archival levels of hypo may be reached in something like five seconds, but residual hydroquinone will take 45 seconds to remove. (The reference may be in my book. If not, it should be.)

This astonishing finding suggests that for an alkaline or near-neutral fixer, the important thing to test for, as regards film, may not be residual hypo but residual HQ/other. Haist could not be explicit about any of this because too much of it fell into the trade secret area. We all have to remember that Kodak aggressively supervised his book. Except for the utmost generality, he was not permitted to make any statement that had not previously been published in the literature. He also wasn't permitted to connect dots which would have made life much easier for future generations of readers

So, again, I'm not entirely surprised if, under some circumstances, an acid fixer (perhaps closer to neutral than not) will give an acceptable wash under some circumstances, with 5-6 quick changes of water.

Those circumstances would have to include excellent condition of the fixer, perfect technique and timing, and a given film emulsion, for whereas it may work with some films, it can't be expected to work with all.

But that still doesn't take into account other residua from the development process which could be damaging.

So now you have to look at what is happening before the fixer step and after developing.

Will there be a stop bath? Will there be a continuous or stationary water rinse? Or will the film be plunged direct into the fixer?

There are all kinds of possibilities for nastiness if there is enough residual developer in the film to be active in the fixer. Dichroic or other fog could result.

So I would be uncomfortable recommending any processing sequence that did not include either (a) at least sixty seconds in a fresh stop bath with continuous agitation, or (b) a continuous water rinse of two minutes or (c) a highly buffered, exceptionally well-preserved acid fixer. Two minutes sounds a lot but it includes a safety factor that is particularly applicable to alkaline fixing because we need to avoid developer activity in the fixer.

I particularly warn against the error, perpetuated by the marvellously bright if obstreperously self-destructive graduate student (to use a style of soubriquet from the Meian era which he will appreciate), of confirming the Ilford method without replicating the chemistry, and that under a wide variety of processing conditions.

It is always possible in photography to make an experimental conclusion that applies in a particular set of circumstances. So if you are an expert as you obviously are, and you find that a particular technique works, I accept that. But I can't accept that as a general recommendation, because when I make a recommendation, it has to be proof against an enormous number of circumstances I can't foresee.

I am grateful to you for forcing me to think this out more rigorously, even if my opinion hasn't yet changed!

My final caution: virtually all after-market rapid fixers are sold with an optional hardener, or were originally sold with such an optional hardener. This means their pH must be relatively acid. Ilford's non-hardening fixers don't suffer from this requirement; therefore the pH could be higher (not neutral or alkaline, but moving up on the scale) and therefore would wash out of film perceptibly quicker. For this reason, in any rapid wash sequence, you have to know the pH of the fixer as prepared and as used. What works with Ilford fixer A won't necessarily work with Kodak fixer B.

With all of this, I think we are beginning to approach conditions where very rapid washing of film is sometimes possible with small amounts of water. But I can't let go of the idea that this can only be true under certain carefully defined conditions, and should not be disseminated as general rules of everyday technique.
 
Dear Bill,

I should like to thank you too, as I shall in future add the further caveat that while I recommend the Ilford wash sequence unreservedly, on the base of my own tests and those of others, I have not tested it with many fixers and that I can only verify it from personal experience with Ilford and Tetenal fixers. I may or may not add that others have found that it works with other fixers: this addition will depend (as we are both very aware) on the space available. I shall of course continue to state that this wash sequence applies only to non-hardening fixers.

I would also point out that I have almost always said that (like others) I find it almost impossible to believe that the Ilford sequence works, and that (like others) I normally repeat one step, or let it sit for a little while in the distilled water after the triple set of inversions -- except, of course, when I am planning on running a test afterwards...

Cheers,

R.
 


I also do this whilst not quite believing that such a simple sequence will work.

In reality, Ilford will have put in a safety margin so in ideal conditions, 75% or perhaps even 50% of their reccomended wash sequence would probably be o.k.

Steve.
 
As an added thought on hydroquinone retention, it is known that hydroquinone itself does not diffuse rapidly and is rather insoluable at an acid pH. It forms a sodium salt or ammonium salt at alkaline pH values. Grant and I know this and so the conditions for wash on the alkaline side are best for removing excess HQ. Bill knew this as well I think, as we see.

OTOH, color developers and some B&W developers are amines or contain amino groups which are more soluable on the acid side, and therefore Metol and the p-phenylene diamines are more soluable on the acid side.

This interesting dilemma was solved at EK when we decided to use the near neutral fix and blix which gave us the best of both worlds. In addition, adding swelling agents and taking advantage of synergy in fixing can speed both fixing and washing at whatever pH. I have done extensive experiments on this with Keith Stephen, and he had developed a whole family of organics and inorganics that accelerated fixing. This latter is never discussed on the internet to any extent, and is rarely used in products sold.

One of these low toxicity ingredients is now sold by several chemical companies, but is so expensive (IDK why though, it is easy to make), so if I can get some I can whip up a super fix that would knock your socks off! No, I won't give you the name. I'm trying to get some myself. Right now, I cannot afford the minimum order.

I may discuss this phenomenon at a later date. Our erstwhile graduate student seems to be totally oblivious to this type of fix in spite of all of his studies. And yet, it is patented by a number of individuals and is written up in Haist and Mees (although disguised ) somewhat to protect outright disclosure.

Just as a caution, one popular fixer out there is so poor that, it spoiled on my shelf before I could get to test it, so beware... Not all fixers are made up to Kodak or Ilford standards. My bottle of test fixes are on a shelf here, and this one spoiled while the Kodak fixer, TF-4 and my Super Fix are still just fine.

PE
 
I just noticed in reviewing this thread that my name was taken in vain. I mean that literally. Very little of my practical work has been done with expectations of long life. Strangely, a lot of it has survived at least 30 years with no sign of degradation. I took many photos between 1960 and 1980 of visiting musical artists while I was principle oboist with the Peninsula Symphony of Newport News and the Norfolk Symphony of Virginia and they are still in excellent condition. This was done while the bathroom was "bath by appointment only." I was in a hurry to get the photos processed between dress rehearsal when I took them and the concert the next day, with a full day's work at NASA between. I wanted to present copies to the guest artist and get one autographed for myself. Alicia De Larrocha, Claudio Arrau, Jorje Bolet (also an avid photographer), Vladimir Ashkenazy and many others are among them.

I have a collection of glass plate negatives that my grandfather took before 1905 that were stored (not preserved) in brown paper envelopes in an attic in West Virginia. The ones that are not in good condition are so because of humidity. The envelopes are what librarians refer to as "cornflakes" of which some are embedded in the gelatine. I have no idea what procedure he used in washing.

I am not about to preach to anyone my technique, which was about 1% good planning and 99% good luck. I am an engineer by nature, which only means that when I have an engineering problem before me, I read books and write equations and do whatever else is necessary to find a solution. I had occasion while employed by NASA to solve problems in aerodynamics, electronics, photography, human factors and some I don't remember. I took one of my instructors at WVU literally when he said "Engineers can do anything." That was about 60 years ago.
 
Since it was an unexpectedly rainy day in Rochster (HAH), I spent part of the morning and early afternoon re-reading Haist and Mees & James on fixing and washing.

It pretty much follows what I have said in my posts here. Well, that is not surprising, as I learned much of it from discussions with the originators of the data. In fact, I spent a lot of time talking about many subjects such as this with others not cited here.

I'm sorry that our 'learned associate' here has chosen to block both my posts and those of Bill Troop, or he would have seen all of the comments on diffusion and etc posted. He might have learned something. He might have learned that there is a lot to be said from years of practical experience and being able to talk to experts in the field daily.

The only thing I might add is that Mees and James describes the washing of fixer and silver complexes out of coatings as an exponential function and show that it levels off after a rapid rate of change. I didn't want to interject math into this, but there is an equation to explain the overall fix and wash and very repeatable curves that are used to illustrate this. In addition, they describe wash aids and hypo eliminators, and describe the pitfalls present in their use as well as advantages.

My overall impression is that they were not in favor of using either of these 'assists' themselves after their survey of all of the literature.

Work since then, as far as I can determine, does not refute any of this information on fixing, washing or wash aids. Mees and James specifically note that slow running water or long soaks in water with agitation are useful for washes. And, furthermore, they stress that any use of a wash aid must be followed by a good wash itself to prevent problems. They note that retained wash aids can lead to as many problems as a poor wash can itself.

I would add that Roger and Bill have made some quite valid points on both sides of the equation though that will have to be considered by us all. I hope Roger has time to go over some of the points I've made about synergy (something rather new here in fixing?) and other items such as the effects of diffusion and agitation. I also hope that our 'graduate student' is humble enough that he realizes that all of us old timers have things to add, even if they go against his established world view of photography and indeed apparently of himself.

PE
 
Continuing to be a dismal day in Rochester and me being unable to take a bike ride as I expected, I continued my research into the maths of fixing. Here is more from L.F.A. Mason, Photographic Processing Chemistry.

Washing, as explained in my last post, is given by a simple exponential function which is as follows:

dx/dt = k(a - x) where this means the change in concentration of the bad stuff (x) in your film or paper changes with time as a function of a constant, and the initial concentration (a). This assumes everything is at maximum, ie exchange rate and agitation for example.

It chages as follows for the real world:

dx/dt = k[(a - x) - w] where "w" = the concentration outside of the coatng, in the wash solution, of the products you want to remove. This means they slow it down as described in one of my previous posts.

So, it becomes obvious that the volume of wash water, or rate of change of water or agitation or concentration or all of these factors govern "w".

It also means that if t = 0, or the wash is short, then the dx becomes infinitely small, or - IT DOES NOT WASH OUT!

This is for the math geeks and engineers out there, but also is proof that you can calculate the effects of all of these factors on the effectiveness of a wash on print or film quality.

I hope it helps spread further light onto this rather difficult matter.

PE
 
Oh, I hear someone saying "how is this exponential".

Well, that is infinitesimal rechnung or calculus my friends.

On integration it becomes the exponential function that Mees and James and Mason both show. I'll let someone else post that if they wish. I already know the answer.

Oh, and BTW, Mason who advocates a long wash with agitation was a member of the Ilford research staff.

PE
 
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[QUOTES=Photo Engineer;460503]
"As an added thought on hydroquinone retention,
it is known that hydroquinone itself does not diffuse rapidly..."

Hydroquinone Clearing Agent. How about THCA? Bill
mentioned the subject years ago on rec.photo.darkroom
and still no THCA.

"Just as a caution, one popular fixer out there is so poor that,
it spoiled on my shelf before I could get to test it, so beware..."

Likely one of those "rapid" ammonium fixers. I've got some of
that to dump as well. What remains of my bottle of anhydrous
sodium is in fine condition several years after being brought into
stock. If one is an off, off, and on such as myself at work in the
darkroom, a dry easy to mix concentrate is the ticket. Spoon
up fresh fix each turn in the lab. Dan
 
I have decided to have a cup of coffee while washing film and to cut the lawn or blow snow while washing prints. Oops- the new lawn tractor I am forced to buy this weekend may cut the lawn too fast. Need to rethink. In any case Canada has decided to curtail all this activity by banning lightbulbs.
Mark
 
The driving force for removal of substance x from the emulsion is proportional to the difference between the concentration in the emulsion and the concentration in the wash water, I would expect. It is easiest to analyze when the washing is done in steps such that the concentration at the end of any step is negligibly different from that in the wash water. If there were no strange phenomena such as osmosis involved, the limiting concentration as time in any one cycle approaches infinity should be the amount of x that entered the wash in the emulsion divided by the combined volume of emulsion and wash water. At that point the driving force is negligible and it is time to change the water. The time constant will be shortened by agitation, but not the end concentration. Thus, if the volume of the wash water is 1000 times the volume of the emulsion, the volume of fixer remaining in the emulsion at the end of a cycle should be not much more than 0.001 times the initial volume. At the end of two cycles, the fraction is 10^-6 times the initial value. At the end of the third cycle it is down to about 1 millionth.

A problem here is that the driving force is also less at the beginning of each cycle than at the beginning of the previous cycle. Nevertheless, we can get a qualitative idea of the process, and if we can measure the concentration of x at in the wash water at the end of a cycle, we can get a pretty good idea of the concentration remaining in the emulsion.

I haven't read this thread as thoroughly as I should have, but I do not recall that a target value for residual x has been set. It can be as small as you wish as long as you don't wish for zero. IIRC, it has been suggested, if not proven, that some residual fixer is desirable. In any case, as long as we have an exponential decay of x with time, whether in steps or with continuous flow, there will be some theoretical residual x. If it is desirable to have no residual x then perhaps a chemical method of removing it is necessary. We just have to be careful not to fall into the trap that caught the emperor when he tried to get rid of a plague of mice.
 

In my previous life I was an engineer as well, and I know what you mean. Now I'm in science world, and the word "engineer" is often used in derogatory way. I usually don't like to hear that. But maybe not today. Some "engineers" and others on APUG seems to do the exact opposite from what you said. They get bored sitting around computer all day, pick a dead issue to tackle with and reverse engineer the existing solutions by reading books, writing equations, and do whatever else is necessary to find something to talk about endlessly.

Also, if all my negatives tested negative of residual thiosulfate every time I tested the Ilford method with 99% of my luck, I think everyone has the 99+ per cent of the luck. I occasionally win grand prize on fine art juried competition, but I never win lottery tickets and I don't even bother to buy one.
 
Hydroquinone Clearing Agent. How about THCA? Bill
mentioned the subject years ago on rec.photo.darkroom
and still no THCA.

Hydroquinone can be washed out at about the same rate as thiosulfate from non-hardening fixer.

This is an excerpt for your own reference. This is cut and paste from OCR of the paper so please pardon some conversion errors.


PHOTOGRAPHIC SCIENCE AND ENGINEERING. Volume 19. Number 2, March/April 1975 ¡"

Some Aspects of Fixation and Washing

A. Green
Research Division. Kodak Limited. Headstone Drive. Harrow. Middlesex, HA 1 4TY. England


ABSTRACT
The course of fixation and washing of silver-halide-gelatin emul·
sions is discussed with special reference to the swelling curves dur-
ing fixation and the emulsion conductivity during washing.

[...]

Monobath Processing-A Special Case
Washing after monobath processing differs from normal
cases because the monobath leaves the emulsion alkaline,
and contains developing agents as well as the usual thiosul-
fates. Hardeners are commonly absent and therefore the
washing out of the thiosulfate is very rapid because very
little is adsorbed to the gelatin. The main problem is the
presence of developing agents, largely hydroquinone, in the
alkaline layer.

We have investigated washing after a particular mono-
bath process in some detail, and a brief look at the results
points to general trends and slightly different requirements for archival permanence.

The "Dentech" process!8 is typical of modern monobath
processes in which a minimum of solution is used to process
each piece of film and is then discarded. In this case a small
water-tight packet containing the film is injected with mo-
no bath solution in the processing machine. The film is pro-
cessed in the machine's agitator, inside the packet, and
then finally is removed from the packet and washed in run-
ning water. It has been shown!9 that in this case, while a
40-sec wash in cold tap water is sufficient to lower the
thiosulfate concentration to the archival requirement, 60
sec is required to dilute the hydroquinone to a level where
it does not give a residual stain (see Fig. 16). These results
would indicate that as processing systems become more
rapid, some consideration should be given to the residual
level of developing agents if, even when the emulsion is fi-
nally at a lower pH, stain is not to be a problem after pro-
longed keeping.

The Figure 16 (not included) shows that hydroquinone level goes down with about the same time constant as the thiosulfate. Due to the difference in the initial concentration and stain-free level criterion Green used, hydroquinone took a bit longer to wash out in this case, using monobath developer and cold 12C washing water.

In conventional (non-monobath) processing, much of hydroquinone gets washed out in the stop bath, fixer bath and so forth, so hydroquinone gets washed out to the same criterion level much faster than Green showed.


Most acid fixers, rapid or not, suffer from poor shelf life, especially once exposed to air or bottled in air-permeable containers. This problem is well known since 1960. Since I have the database at hand, I'll give you the abstracts of relevant research. Again, these are OCR'ed text and I haven't hand corrected them.

PHOTOGRAPHIC SCIENCE AND ENGINEERING
Volume 4, Number 2, March·April 1960
The Stability of Concentrated Ammonium Thiosulfate Solutions at High Temperature
G. 1. P. LEVENSON, Research Laboratories, Kodak Ltd., Harrow, England
Sodium and ammonium thiosulfate liquors were stored in sealed glass tubes at 60°C. The effect
of pH value, sulflte concentration, dilution, etc., on the time required ro bring about deposition of
sulfur from the solution was observed. The stability was not primarily dependent on whether so.
dium or ammonium salts were used. The stability rapidly decreased as the pH value and sulflte
concentration were lowered. Sulflte reacted with the thiosulfate and when oll the sulfite was
consume~ the thiosulfate decomposed.

The Stability of Concentrated Thiosulphate Solutions at High Temperature. Part II. The Loss of the Sulphite
G. I. P. LEVENSON (Fellow) and M. G. RUMENS
Research Laboratories, Kodak Limited, Wealdstone, Harrow, Middlesex

ABSTRACT. The decomposition of concentrated thiosulphate fixers at elevated temperatures occurs because
the sulphite is converted into sulphate and thiosulphate in a reaction catalyzed by the thiosulphate. When
the sulphate is gone the thiosulphate decomposes giving sulphur and sulphurous acid which latter is also lost
by the above mechanism.
 
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The driving force for removal of substance x from the emulsion is proportional to the difference between the concentration in the emulsion and the concentration in the wash water, I would expect.
This is true only for the diffusion part. The Donan membrane property applies to gelatin coatings, but there is also ADDITIONAL problem of adsorption of thiosulfate to gelatin as well as silver image. The latter is much slower process with greater time constant. It's just that in the case of film and RC washing the relative importance of the desorption process is much smaller than baryta paper.

A problem here is that the driving force is also less at the beginning of each cycle than at the beginning of the previous cycle.
In practical terms, you'll need more agitation and longer time in later cycles.

I haven't read this thread as thoroughly as I should have, but I do not recall that a target value for residual x has been set.
I use current ISO standard for "other fine grain films" although I give a generous safety factor.
 
A very interesting thread, but what are we, as practical photographers, to do with it?

What I take away are a couple of things - one, since I don't use an acid stop bath, perhaps I should extend the time the negative spends in the water between developer and fix to better remove developing agents. I now go 30-seconds with agitation.

Two, I use an alkaline fix (TF-2) with non-T grain films. Keep better track of the number of negatives put through it to be sure the fixer is fresh, and wash using something like the Ilford method but allow the negatives to soak for five minutes between washes.

Is this along the right track?
juan
 

I won two chance prizes in my 80 years. Both were door prizes, one a bottle of wine at a church supper, the other a quilt at a local ballet performance. Make that 3. I won a bicycle by contributing 25 cents to some charity. I already had one, and the fellow who sold me the ticket coveted it, so I said "It's yours." He thought I was out of my mind, but I reminded him it only cost me a quarter and it would cost a lot more to drive the 25 miles over a toll bridge to pick it up. Besides, he was a good friend. How often can you make someone happy for a quarter?
 
A very interesting thread, but what are we, as practical photographers, to do with it?
The best thing to do, probably, is to ignore threads that are trashed by some people you see...

What I take away are a couple of things - one, since I don't use an acid stop bath, perhaps I should extend the time the negative spends in the water between developer and fix to better remove developing agents. I now go 30-seconds with agitation.
Developer retention is not an issue if you follow any of the archival washing sequence. Practically speaking, it is a problem only in monobath system. Don't worry.


The "five minutes between washes" is unnecessary. The only reason to give more washing than what's specified in the Ilford system is to remove sensitizing dye, if you care, but not thiosulfate or anything that matters on archival standard.
 
Dear All;

Ryuji, a brillant person but with no chemistry or photography experience beyond what he tells us (no data, just words), chooses to ignore the published work of many reputable researchers including Mason, from Ilford, who essentially repudiates the Ilford test in his textbook, and Levenson, Haist and Mees and James who were towering figures in this field with more years of experience than Ryuji has lived.

I always say "Do what works for you" but I hesitate to disregard the results obtained by actual analytical results. I have posted the maths, the concerns and the comments by many of these workers. I abide by them myself.

Sometimes things seem to work. The real test will come only after years of keeping. If you don't believe me, read the seminal work by Ctein who sold prints he thought were archival even after tests. After customers began complaining about a batch of prints, he ran additional tests under different conditions and discovered his prints were not archivally prepared. He makes his living by selling photographs and writing about photography. His reputation was at stake here. He fixed the problem, replaced the prints and wrote about his experience. BTW. He over washed. So, there is a sweet spot that the experts have found for us. We should listen to them.

Do what you wish. Remember that even a figure like Ctein was blindsided.

PE
 

Dear PE,

Hold on. Let us not conflate negs and prints.

I hesitate to mention it, but perhaps those who want their negs to last forever are suffering from delusions of grandeur.

Maybe a neg (and even a print) that lasts 'long enough' is better for art and history.

Cheers,

R.

Cheers,

R.
 
It is very obvious to anyone who read and understood the Ctein's articles that the argument of Ron Mowrey (the portion quoted by Roger) is pathetically incoherent. Ctein had problems with RC prints that were processed to archival standard due to self-induced oxidative attacks. The takehome message from Ctein article is that you must tone the print or at least use Sistan if you want to ensure long display life of b&w RC prints, and it is a good and valid advice. It has nothing to do with Ilford washing procedure of film.

A little caution for fellow APUGers. There are some people on this site that routinely attack others, mostly targeting well known figures. They probably try to gain their popularity by trying to damage the credibility of others. This is a very common phenomenon on the internet forums, not just photography-related forums. Those people often sprinkle their postings with technical terms, names of other authoritative people or corporation, equations, cut and paste or summary of what's printed in books, etc. Lots of fabricated stories or "hearsay" liberally sprinkled with big names, but the stories are never confirmed with solid references. They sometimes rely on an illusion that they are with the "majority consensus of the experts," and other times another illusion that they are the experts. One favorite pattern is to pick a dead issue and try to warn people of problems (that do not exist or are long solved) to get attention. Archival processing and image permanence are good topics because everyone has a certain level of fear. Those people spend all their time on the internet and their life work is to become an internet hero by trying to prove they know the problems overlooked by others, and they can solve the problem. Or it may go like you could do better than others. So far it may seem to be harmless (other than wasting your time), but they often distort the fact or gloss over when their errors are pointed out. Remember, the goal of internet forum professionals is to win the debates and become a hero in the small virtual society. Being truthful is of secondary concern. They have endless amount of time to keep posting, re-posting and trashing another thread with same stuff and so forth, forever, on a simple stupid problem that's long solved. Don't get caught on those. Your photography skill won't get better by listening to them.

Controversy on Ilford washing procedure is a dead issue. Ilford is actually smart not to get on this thread and join the endless battle. This gives Ilford more credibility.

Ilford washing sequences (both film and FB prints) are very popular and widely used. If anyone had a hard evidence that the procedure fails, you would hear that news from Ilford. Someone would publish it. The absence of credible publication demonstrating a problem of Ilford washing sequence is a good sign of absence of such problems. I wouldn't use this logic universally, but it is appropriate if you consider the widespread popularity of this procedure. If there were indeed such evidence well known to Kodak, Kodak would certainly exploit that to their business advantage. In reality, Kodak publications, old or new, don't even acknowledge that Ilford washing sequence exists.
 
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