The truth about Clayton fixers?

[jim_appleyard]

Were the tests in question done with fixer mixed with distilled water? Could all the stuff in tap water make a difference in the amount of time needed to clear film? Just curious.

[lowell_huff1]

Hello Bill:

I apologize if I got a little defensive. I did not do my clearing tests with TMax 400. If memory serves, I used both Agfa and Ilford Films. Speaking of TF-4 Fixer, obviously, you are a "Lab Rat" with some knowledge of chemistries, my question is "how can you accept a product formula that is so clearly out of balance that you have to shake it vigorusly before use?"

[rowland_mowrey]

Lowell;

 

The 'shake before use' and 'stir vigorously' are both precautions on some EK developers which separate into two phases. Notable for this was the EP3 developer of a decade ago.

 

Having phase separation or crystallization in the concentrate as shipped from the factory is no detriment whatsoever to the customer and often saves on shipping costs for water. As long as everything dissolves when mixed to working strength, which TF4 does, there is no problem. The EK product was very hard to mix.

 

So, your comment is a non-problem in my many years of manufacturing experience.

 

Ron Mowrey

[ryuji_suzuki]

Is this going to a mud fight, not discussion of facts?

 

Here is one fact. I have a well tested rapid fixer formula (unpublished) that operates at the same pH as TF-4, but buffered with a superior buffering agent which will never form sediment, and allows considerable amount of stop bath carryover before the pH becomes too acidic. And it has enough agent that accelerates washing in plain water, even if the pH drops acidic. It also has some antioxidants to protect the sulfite in the fix so that the superior dye-washing power lasts longer. It clears chlorobromide emulsions in about 5 to 10 seconds and iodobromide camera negatives in 0.5 to 3 minutes. Does that help?

[ryuji_suzuki]

Many liquid concentrate products form sediment when stored in very cold storage room but they become redissolved upon return to typical room temperature of 20C or so. This causes inconvenience, but it's less problematic than sediments that don't dissolve until dilution. With the latter, it is difficult to use a portion of the concentrate and keep the rest undiluted for later use. But sometimes people need to put more chemicals in the concentrate and there may be no better way unless the formulation is completely revised.

[lowell_huff1]

Hello Ron:

Have you seen a bottle of TF-4 ? It comes with an inch of "mud" in the bottom of the bottle. B & W formulas, without exception, should always be clean and clear.

[lowell_huff1]

Hello Ron:

Have you seen a bottle of TF-4 ? It comes with an inch of "mud" in the bottom of the bottle. B & W formulas, without exception, should always be clean and clear.

[rowland_mowrey]

Lowell;

 

I use TF-4. The 'mud' is a clear white suspension of what I suspect to be borate salts. They dissolve completely when the working solution is prepared and present no problem to me.

 

I'm only pointing out that separation and crystallization need not be a problem and is not a problem.

 

Ron Mowrey

[conrad_hoffman]

FWIW, I use TF-4 and never mix the whole thing. I just shake it up and immediately pour out the required amount for dilution. Never had a problem, and I think it's a really great product. Now, just to play devil's advocate, I also use Kodak powdered fixer with no problems either. Question- is there a bad fixer? One that's to be avoided because it doesn't perform as advertised? IMO, not, and the whole question here comes down to reproducibility of results- what's the clearing time under certain defined conditions? With enough info on the process, any of us should be able to get the same results, and thus prove or disprove marketing claims. BTW, I was reading C.B. Neblette's Photography, Its Materials & Processes (5th ed) last night, and modern wisdom on fixing doesn't seem one iota different than what was known in 1952, a couple years before I was born.

[ryuji_suzuki]

Conrad, for thiosulfate-based fixers, the result is pretty much the same as long as the material is fully fixed and washed. If the material needs additional hardening, the degree of hardening can vary among formulae/products. It's hard to make a good, well hardening rapid fixer that has long shelf life, especially if the fixer is used in machines with low replenishing rates (for example, see US Patent 6653060).

 

One concern with agents other than thiosulfate is that we don't know if the fixed image is archival unless it is tested with variety of materials and conditions. Some silver halide solvents can change the shape of silver grain and filaments when they come in contact with the material in or after the stop bath. For example, thiocyanate or high concentration of chloride is known to do this. This may affect the susceptibility of the image to environmental oxidizing agents. So nonconventional fixers are best avoided for works where permanence is important, or the fixer must be tested before using. But these fixers (or stabilizer, rather) containing thiocyanates are generally used for stabilization processes where archival property is not very important.

[rowland_mowrey]

Ryuji;

 

I would like to remind you that Sistan, a noted post fix bath, is used to improve the permanence of silver images.

 

It is mainly thiocyanate.

 

Both thiocyanate and thiourea have been cited in the literature for enhancing the stability of silver images by decomposition to form silver sulfides which are quite oxidation stable. This is similar to the method by which a small amount of thiosulfate stabilzes silver images. (By stabilization, I am not referring to stabilization processes but rather true fixation followed by wash and dry with the use of a Sistan rinse which enhances the keeping properties of the final image.)

 

I refer you to the excellent article on this subject by Ctein.

 

Ron Mowrey

[conrad_hoffman]

Everything I printed back in the '70s was fixed in Kodak powdered fixer for 5-10 min, and washed for 30-60 min. Most of my fiber prints are in good but not excellent shape. The ones that weren't mounted show almost no deterioration. The ones that were dry mounted on that cheap white/beige pebble mat board, and stored in a 8x10 paper box, are generally a bit yellowed. Some show a bit of cracking of the emulsion. My RC prints from the same time period are essentially perfect. They've held up much better than my fiber prints. Something I've always wondered about- the fiber prints that haven't held up well were generally printed on inexpensive off-brand papers from the NYC vendors at the time. They were usually double weight with a pebble surface. The prints on Kodak paper, on average, seem to have fared better. Regarding negatives, I've never seen any deterioration of my negatives, my dad's negatives, or my wife's grandfathers negatives. IMO, if you even come close to following the instructions, it's hard to have a permanance problem with negs. Most so-called processing problems are likely storage condition problems.

[bill_troop1]

>Hello Ron: Have you seen a bottle of TF-4 ? It comes with an inch of "mud" in the bottom of the bottle. B & W formulas, without exception, should always be clean and clear.<

 

Lowell, it would be very easy to remove the mud from TF-4. But then you'd remove the active accelerant chemicals. Do you think it's possible that there's a reason TF-4 is five times faster than CP Fixer? Like, maybe, more, and better, chemicals?

 

In the meantime, we're waiting for your test results.

 

You have told us that CP clears film in 15 seconds. My tests on TMAX 400 show that in fact it clears 11 times slower: 165 seconds. Have you got any data to contradict this?

 

It only takes a few minutes to conduct a clearing time test, so what's the problem?

 

Does Clayton have a darkroom? Does Clayton have a test facility? Does Clayton actually test its products? Could you identify the chemist who designed your formulas? Where did you actually get these formulas?

 

Could Clayton state on the record just how long it takes your CP Fixer, fresh, at 68 degrees Fahrenheit, to clear TMAX 400 film?

[bill_troop1]

Ron & Ryuji, I am so annoyed you are starting a discussion on thiosulfate/thiocyanate, and wish you would start a separate thread, but since we are on the subject, I would like to say a few things.

 

My thinking has evolved considerably in this area since I last made some -- shall we call them rash? -- remarks on this subject during a thread with Ron which I hope we have all forgotten. A superficial reading of the literature easily provides the impression that thiocynate/thiourea solutions are not archivally suitable. For example, Haist, p. 597, "Today, the combination of thiocyanate and thiosulfate is often used for the rapid fixation of photographic materials, particularly for those applications where rapid access is more important than the long-time keeping characteristics of the image."

 

At first glance, this gives the impression that thiocyanate is something to avoid. But that is not the case. There is a simple reason for this. The historical fact is that the published formulas for thiocyanate/thiourea (TT) fixers were used for rapid stabilization processing, where there was no time to wash and no need for archival stability. Therefore, historically, there has been a tendency not to examine the potential of TT fixers in archival processing.

 

TT fixers have tended not to be used for materials where archival processing is desired because they are more expensive than thiosulfate solutions, and because extreme speed was not generally considered an important design consideration where archival processing was desired. There is also the fact to consider that even though TT fixers may shave off a minute of processing time here and there, washing times will still be as long as other processes unless there is very careful design of pH and other parameters.

 

In other words, TT solutions are luxury processes. There has also been the tendency to confine TT solutions to machine processing where every parameter can be controlled. One reason for this is that TT fixers must be very carefully designed to avoid reticulation or excessive softening of film and paper emulsions. Another is that thiourea-containing solutions must be handled more carefully than pure thiosulfate solutions.

 

A TT fixer for general use therefore requires considerably more testing and product development time than a conventional thiosulfate fixer.

 

All of that said, there is reason to suppose that TT fixers may confer archival stability significantly superior to pure thiosulfate fixers. Relatively recent research by Agfa and Ilford indicates that materials fixed in thiourea or thiocyanate may be substantially more archivally stable than materials processed in thiosulfate even under the best circumstances. It now even seems probable that a material fixed, for example, in a mercaptan fixer, may decisively benefit from a post-processing treatment involving thiocyanate or thiourea.

 

My conclusion is that TT processed materials, _when adequately washed_, may represent the cutting edge of what is currently achievable in archival fixing. I don't think Agfa Sistan represents the best way to use TT to confer additional archival stability for several reasons, including the application method. I think a carefully designed TT fixer, and carefully controlled washing process, may turn out to be superior.

 

As Conrad has pointed out, it is relatively easy to process films archivally. Some recent research postulates that the film base may be the limiting factor in the life of most negatives. But with prints it is a completely different matter. We need superior print stability, and TT fixers may turn out to be the best way to provide it.

 

Conrad, the fact that your RC prints are faring better than your fibre-based prints suggests to me that the fibre-based prints were not adequately washed. Washing with the acid fixers generally used at that time should have extended to several hours, and providing adequate agitation for several prints is not easy.

[jay_de_fehr]

I've been using Ron's Superfix, which contains thiocyanate and thiourea, since shortly after he published the formula here, and have nothing but praise for it. I will not even consider another fixer until he publishes his new and improved formula. Thanks Ron.

 

Jay

[ryuji_suzuki]

Ron, first of all, the concentration of thiocyanate and other active sulfur compounds in fixing solutions is a lot higher than the working solution of Sistan. Secondly, fixation by a bath containing thiocyanate and post-fixation treatment with dilute thiocyanate have very different conditions of operation. The effect thiocyanate can have on grain morphology is very different between these cases. There are published reports on the morphology change by pre-fixation treatments of some silver halide solvents. One common way to measure it is to radioactively labele grain surface by adsorbing thiosulfate with radioactive outer sulfur, which makes monolayer coverage on silver, and then measure the radiation. This gives you a measure proportional to surface area of the total grain. Total grain volume is also measured by any of the standard methods. Treatment in thiosulfate solution greatly reduced the surface-to-volume ratio of the grain. People were also studying these with SEM. You can find these papers in J. Photo. Sci. and other journals from 1960s.

There are also agents that are known to stabilize grain morphology (such as iodide, PMT). Anyway, I simply don't buy an argument that Sistan enhances permanence therefore thiocyanate fix is an archivally sound choice. Such a claim must be carefully tested. I built my accelerated peroxide fuming setup some time ago and tested various test strips processed in different ways. It is really shocking to see a small difference in processing can sometimes visibly change the samples' resistance to fading. Ron, if you are formulating a revolutionary fixer, I highly encourage you to build your own peroxide fuming test setup to confirm its archivalness. There are a couple of papers in J. Imaging Technology from 1990s describing peroxidide fuming test systems. One of them was written by IPI people, one by a Japanese author. IPI system used a separate relative humidity "buffer" while the Japanese system relied on precise dilution of peroxide to aim the levels of peroxide as well as humidity in a closed chamber.

 

Conrad, I agree that storage condition is an important factor in ensuring good condition of prints and negatives. However, the susceptibility of the material depends on the emulsion, processing chemicals, processing techniques, and so on. If you can store prints in ideal condition (low humidity, low temperature, sealed in an inert, gas-tight container, dark storage) then prints will enjoy a lot longer life. But in real life we make images to enjoy viewing and such prints are kept in more accessible way, often far from ideal storage condition. The goal of processing end for permanence is merely to maximize, or, at least raise to an acceptable level the resistance of the image to such factors as environmental pollutants. Well toned and washed prints can enjoy very long life at room temperature and with occasional display, though untoned prints are more likely to suffer unless they are stored in closed, low humidity environment. Careful processing and perhaps extra toning step may be a lot cheaper, convenient and effective solution when cost and benefit are considered with the material, processing, and storage as one system. (I am not suggesting that toning would remove the need to pay attention to storage. I'm merely saying that proper processing and toning would make the prints more durable when ideal storage condition is impractical or too expensive.)

 

That camera negative films are much less likely to degrade during storage (compared to document films, motion picture negatives, and prints) is well documented. This is related to presence of sufficient amount of iodide in the pictorial negative emulsion, which helps to stabilize the grain/filament morphology. Similarly, motion picture positive films contained iodide and they were more stable. The practice to add some KI to fixing bath for document films is consistent with this knowledge. More recently, certain antifoggant (PMT) was found to increase image stability with medical X-ray films. While processing chemicals are closer to the end user's attention range, manufacturers improve products from many aspects like this.

 

Chemistry of image degradation and methods of studying or improving permanence is one whole area and it's getting removed from the focus of current thread. I have posted a list of key papers in pure-silver list some time ago, so interested readers are encouraged to find the original research papers and read them.

[ryuji_suzuki]

Bill, I'm not talking about superficial reading and pattern matching of the chemical names. I'm talking about crystalline structure of grain surface and gross morphology of grains. These are affected by the choice of agents as well as concentration, and all other usual factors. If you make a major change in a processing system like this, and if you argue it is archivally sound, you better have some solid evidence to back up your claim. Anyone can dispute hypes on clearing time until we get bored but the issue of permanence takes a serious effort in theoretical considerations, accelerated tests, real-time tests, etc. and are often expensive to pursue. Look at how much effort people are making to test longevity of inkjet dyes/pigments/paper. Same thing was done for silver-halide materials in various standard processing techniques from 1950s to present. When I change something such as toning technique, I run my own test to confirm that the result is good enough for me. This is the only way to know some treatment is effective or not.

 

My upshot is that calling something "archival" legitimately is not an easy thing.

[larrydressler]

I think that Manufactures have not kept up with the Film Manufactures ... Send all our Jobs to Mexico and China and things change .. 3rd party is even worse. Best thing I found with a new adventure is see it feel it test it test it test it test it .......

[kirk_keyes]

I have to say that I fully agree with Ryuji on the issue of premanence vs. fixing speed. I'm much more interested in the print lasting 100 years, than my having fixed it in less time.

 

Bill wrote: "Needless to say, when speaking of clearing time tests here, we are presumably referring to best possible results with fresh fixer."

 

And don't you think that someone trying to show the fastest results will also pick a film that clears the fastest, and not go looking for the one film that takes the longest?

 

Ultimately, I really don't care which is faster. Especially when we are talking seconds....

 

I use a two bath fixing procedure that is sufficiently long to fix the film with a nearly used first bath and then fix with a second bath for an equal amount of time. Takes me twice as long to fix, but I have great confidence that my procedure will produce lasting results.

 

Bill - I hope you'll get your formulation tested for permanance, perhaps you could talk Wilhelm into helping here?

 

And also, I hope you'll make safety and handling instructions for the TT class of fixers clear on the packaging. While most people may think that thiocyanate is the big safety concern, as you originally did in the thread of yore, I would say that the thiourea is a much bigger hazard here. I know many people use it for sepia toning, but I'm not sure that most people know that it has a pretty high hazard risk.

 

Many MSDSs list thiourea with a "Health Rating: 3 - Severe (Cancer Causing)" and state "Lab Protective Equip: GOGGLES; LAB COAT; PROPER GLOVES". But they also include the info "WARNING! [...] POSSIBLE CANCER HAZARD. MAY CAUSE CANCER BASED ON ANIMAL DATA. Risk of cancer depends on duration and level of exposure." (Taken from the JT Baker web site: http://www.jtbaker.com/msds/englishhtml/t3107.htm )

 

Just let people know they need to use more personal protective equipment and take extra care than they would for standard fixers.

 

Kirk

[keith_tapscott]

I`ve read about alkali fixers in the past, how come Kodak, Ilford etc, don`t make them? Also, I read some where that Tetenal Superfix Odourless is supposed to be pH neutral.

Can TF-4 be bought in the UK?

[keith_tapscott]

Kirk Keyes makes an interesting point about safe handling of chemicals, I`m no chemist but I`m sure that provided photographic chemicals are treated with respect, that they`re no more dangerous than any other house hold items such as cleaners, bleaches, disinfectants etc.

From what I can see, water seems to kill more people each year than any other substance, the recent Tsunami incident in late December makes this point.

[rowland_mowrey]

Kirk;

 

I agree completely. I would like to point out that thiourea and derivatives of thiourea are found naturally in a variety of plants. Are we to avoid them as well? Should the EPA list those so we should avoid them? Do florists have to publish an MSDS for bouquets? Well, I think you see my point, everything has a hazard associated with it.

 

We use a lot of toxic chemicals in photography. I will try to avoid all really toxic chemistry. You will never see the ultimate fix from me. Ammonium cyanide would probably be a good example of the ultimate NO NO, but the ultimate fixer. Enough said.

 

Ryuji;

 

I think that Bill has pretty much stated my position as well. I need not make any more comment about TT fixers.

 

As far as keeping tests, I began running keeping tests in 1965 and continued steadily until about 1980. That would be about 15 years intensive experience with light, heat, humidity and on both images and raw stock as well. So, I think I can say I fully understand the problems.

 

I can say this; the peroxide fuming test must be fully verified with real-time keeping experiments before being fully acceptable. Sometimes, it requires years for adequate verification.

 

The peroxide fuming technique was described in the 90s, and some of the real-time tests for verification are probably only now becoming available.

 

I'm sure that you are aware that diffusion of high concentration of peroxides is not always indicative of the real time effects of oxygen diffusion. This is due to other factors such as adsorption of oxygen on or in baryta, resin, and titanox. It also involves reaction rates of the free radical chain stoppers incorporated into the papers to prevent degradation by oxygen. Peroxide infusion can swamp this otherwise effective method of preventing image degradation.

 

I have seen images destroyed in accelerated keeping tests which survived for years and years under a variety of natural keeping conditions, and I have seen images survive extended accelerated keeping which were destroyed by 1 - 2 DAYS keeping under normal conditions.

 

Ron Mowrey

[ryuji_suzuki]

Ron, I think you need to get more recent inputs from 1990s before you say you are confident. In the current understanding of image deterioration of black-and-white materials, the biggest problem was realized mid to late 1980s, for which variety of test methods were devised and preventive measures established in 1990s. Plus, the major chemical mechanisms for image fading of color materials and b&w materials are very different. You shouldn't assume knowledge on one area applies to the other.

 

The biggest problem with today's b&w image permanence problem is resistance to environmental pollutants. Some form of silver image is more susceptible to this than others, and we need a way to see this in a reliable, controlled condition, because fluctuation of pollutants in real world is fluctuating and unpredictable. Modern peroxide fuming test standard is actually a harsher testing condition than today's average office environment, so that images that stand well in the test are most likely adequate in holding up in the real world. Some people use compressed oxygen test when they need test condition more comparable to real world, mostly to get realistic estimate of image longevity for non-archival commercial and medical photography.

 

Once the image is stabilized with toning treatment, for example, to increase the resistance to environmental oxidants, in the b&w world, we can apply the old wisdom of archival storage to take care of other problems.

 

Effective protection of the image is done by identifying the specific weakness of the image (attacks from environmental pollutants, humidity, residual chemicals, etc.) and designing test standards and treatment strategy to remove the very weakness we are dealing with. Blanket statements of nonspecific knowledge on image stability is hardly useful or reliable to say the least.

[rowland_mowrey]

Ryuji;

 

I know that color and B&W image deterioration proceeds by different means. This is one reason why peroxide fuming is more revealing (but not perfect) for some keeping conditions for color than for B&W materials. Sulfur compounds in the atmosphere affect B&W materials for example, but have little effect on color images. Heat, humidity, light, oxygen and sulfur are but a few and each has an effect on color and B&W images to some extent. Formalin, insecticides, paint solvents, cooking odors, fungi and bacteria are other items that contribute to deterioration of images. Have you read any reports on these latter items? Do you know what to use to prevent bacterial attack or fungal attack on images?

 

This is a complex issue that I have studied for years. I saw my first example when I was about 12 years old, viewing negatives and prints I had made when I was 10 or so. I had not fully understood how important washing was, and the negatives and prints were badly stained and faded. I have kept those pictures as well as color pictures from the same era (E1 and C22) to this day!

 

So, you are trying to teach me something that has been in my mind as a major topic for nearly 50 years. And it was a topic I worked on for about 15 years. I jumped into the topic of image stability with both feet, so to speak.

 

I too could refer you to much work done on the subject, but this becomes tedious to the other readers as well as me. Remember, I worked with many if not most of the people who published the work at EK that you have no doubt studied, and I am quite familiar with unpublished work as well as the work of Wilhelm.

 

Ron Mowrey

[ryuji_suzuki]

Ron,

<p>

I'm presenting a bit of details of what is my concern about introducing a new fixing agent to the permanence issue, in response to Conrad's post in this thread. I'm merely saying that no one knows about permanence of th eimage processed in a new system unless it is fully tested, and also presented summary of standard techniques used today. You're repeating very vague general statements that you know it all and no one else has to worry about it, but you presented very little specific aspects of what you know and what you tested in relation to permanence of images fixed in your fixer formulation. All I am saying is that unless you test such in enough number of methods, including current standard test methods, no one can say that the result is archival. You are appealing to empty "authority" of experience predating the major problem whose effective preventive measures became understood only in 1990s. It only takes a good library research, building apparatus and testing the material. Unless you do that, what you say is nothing more than a speculation.

<p>

<b>To everyone:</b>

<p>

I hate nonsense and I would openly share equally critical review of products, work, etc. regardless of whether they are by Ron, Bill, Gainer, or anyone else, regardless of professional affiliation. I also apply my own ciricism and accept valid criticisms from others to my own work.

<p>

Before I abandon this thread, I might say that people on this forum are spending way too much effort in trying to damage the credibility of the others by various non-constructive ways. Marketing hypes in clearing time, sediments, human toxicity, environmental harm, uncertainty in archivality are <b>REAL PROBLEMS</b> that we know exist, and many of which we also know how to fix. There is no use in pettifogging and defending the known shortcommings of these problems. This thread is increasingly driving towards slandering others' problems while putting your own aside. This makes no sense, as long as science and technology are concerned. The only way to make things better is to address known problems and come up with something that eliminate problems whenever possible. It is a matter of whether the product factually delivers what we expect, but not a matter of belief or of personal pride. I see increased nonsense when some people put more emphasis on the latter terms. Those are exactly what paid advertising space is for.

<p>

A competent engineer must have a critical eye toward their own work to identify the weakness before others do, and fixing the problem before the work is offered to others. This is a real pride of an engineer. Pettifogging, nonesense, marketing hype and such are no substitution for hard work. Get some real work done.