Super Fix

Cordiality may come with time, but at least we're unearthing some interesting information. This exchange encouraged me to figure out something I've been wondering about. I use Kodak Indicator Stop Bath because it's an off the shelf item locally. It appears to contain acetic acid, bromocresol purple indicator, and water. I've always wondered what percentage acetic acid it contains. They list two dilutions, one for normal use, and one for graphic arts. That might be compared to traditional formulas SB-1 and SB-1a, unless some recent discovery suggests those concentrations are wrong. I doubt it, based on how long the solutions keep working. If they're right, and if my math is right (check it!), Indicator Stop Bath is about 84-87.5% acetic acid, a far cry from 28%. I don't think anyone could reasonably argue that Indicator Stop Bath isn't a common darkroom item, or that it presents an unacceptable hazard, having been sold and used since I was a teenager. Yes, it's slightly more dilute than glacial, but not a lot, and it shows that there's no one answer to the question of what can and can't be considered safe. (SB-1 is 48 ml of 28% to a liter of water. KISB is 16 ml to a liter of water. The graphics arts versions are SB-1a, 125 ml of 28%, and KISB, 40 ml, to a liter of water.)

 

Changing topics, I question how much of the "old" research on fixing and washing is valid on "new" materials, and how much difference there is between manufacturers. For film, my practical experience suggests that any fixing process used at 2-3X the clearing time, followed by at least 15 minutes of wash, is adequate. In 35 years of processing film, I've never had a single negative deteriorate in any way. It's just a non-issue. For the most part, I've used Kodak Powdered Fixer, but for the last few years I've used TF-4. (Except for Plus-X with its excess purple dye. Kodak Powdered Fixer solves that completely.) Prints are another matter, but longevity is so storage dependent, I can't say much of anything with confidence. Some of my 35 year old prints were poorly fixed, some were nicely double bath fixed, some used HCA, and some even used the dreaded HE-1 hypo eliminator treatment. They all show similar deterioration, a bit of yellowing, and physical damage they've picked up. The process didn't seem to make much difference. IMO, they'll be viewable in ok shape for another 50 years or so. Interestingly, my early RC prints on Kodak paper have held up better than my fiber prints of similar age. All my prints, both fiber and RC, were fixed in Kodak Powdered Fixer. Few were toned. The hardener in the fixer has never caused me any problem with selenium toning. Will "new" materials fare as well, using my antiquated methods? I can't say one way or another, but I'm not terribly worried about it.

>But since W.E. Lee's disturbing papers showing that a very small >residual amount of thiosulfate can have a stabilizing effect on b/w >materials, there has been more reluctance to work with thiosulfate >substitutes.

 

Has anybody done any verification of this work? Has this been update

to relate to films and papers used by the average photographer?

 

I've heard that alkaline solutions premote "grain clumping". How does this effect apply to the "all alkaline processing" philosphy of todays developing trend?

> ... if my math is right (check it!), Indicator Stop Bath is about 84-87.5% acetic acid, a far cry from 28%.

 

Your math is correct. According to a recent MSDS, the product s 85-90% acetic acid, 10-15% water, <0.1% Bromocresol Purple. That is a surprise to me; I had always assumed it was 28%. The MSDS further states that the vapors are flammable above merely 108 degrees F, not an unheard of temperature in summer darkrooms. Goggles and a face shield are recommended, also a NIOSH Acid-gas respirator; just the VAPORS my cause burns; repeated exposure "may cause pharyngeal edema, Chronic Bronchitis, etc."

 

>Changing topics, I question how much of the "old" research on fixing and washing is valid on "new" materials, and how much difference there is between manufacturers.... [All prints] show similar deterioration, a bit of yellowing, and physical damage they've picked up. The process didn't seem to make much difference.

 

Taken on its face, that might seem to indicate that environmental factors could have more weight than processing factors. If so, it would be scary. In any case, I don't think the question is really, "how valid is the old research on new materials", but rather, "how valid is the old research period?" although I may be missing the point on that one.

 

The answer is, nobody knows much. Take the question of the film base. It was bedrock science for decades that cellulose nitrate degraded vastly more quickly than cellulose acetate. But research in the 1990s showed that science was wrong, and the acetate base can actually degrade faster in some collections. (P. Z. Adelstein, J. M. Reilly, D. W. Nishimura, and C. J. Erbland, "Stability of Cellulose Ester Base Photographic Film: Part I Laboratory Testing Procedures," Journal of Society of Motion Picture and Television Engineers, 101, 5:336-346, May 1992.) (There was similar surprise when some acetate-based 78 rpm sound records turned out to have a greater than 30 year life. The late Institute of Sound in New York was founded in the 1960s by Richard Stryker primarily to address that problem.)

 

>my early RC prints on Kodak paper have held up better than my fiber prints of similar age.

 

Could that be due to better washing, or to some other factor?

 

>Has anybody done any verification of [W.E. Lee's] work? Has this been update to relate to films and papers used by the average photographer?

 

No. There was inadequate funding to pursue it further. I spoke to Lee years ago about this and he wouldn't and probably couldn't say much beyond what he had published. If anyone else has done any substantial research, I am not aware of it. The unexpected death of Klaus Hendriks, perhaps the primary instigator of concern in this area, was an enormous blow. He was an effective noisemaker.

 

>I've heard that alkaline solutions premote "grain clumping". How does this effect apply to the "all alkaline processing" philosphy of todays developing trend?

 

The traditional wisdom that alkaline solutions promote grain clumping means only this: that relatively more alkaline developers will tend to produce more grain clumping than relatively less alkaline developers. In other words, development in D-76 will produce less clumping than development in DK-50. Haist suggests that the problem may not be so much the actual pH, but the time of development and degree of contrast. To minimize grain clumping, exposure and development must be at the possible minimum. However, "some alkalis, such as sodium hydroxide, appear to have a disintegrating effect on the gelatin of the emulsion layer. This action gives the silver particles a greater chance to come together to form clumps, thereby increasing graininess. Developing agents requiring the stronger alkalis may become associated with the production of grain, even though some of this may be due to the action of the alkali." (Haist, v. 1, p. 395.)

 

All practical film developers have a pH of at least 8. It would seem that fine grain development is usually achieved within the range of pH 8 to 9. For reasons which have never been satisfactorily explained, a borate buffer system seems to much more photographically effective in securing a high quality fine grain image than a carbonate/bicarbonate system of equivalent pH. Alternate buffer systems, although attractive, are, according to Zawadzki and others, much too expensive to be practical.

 

In any case, grain clumping, so far as we know, is only affected by the alkalinity of the _developer_ solution, not by any other part of the processing cycle. However, there are some assumptions here. (1) Alkaline post-development processing will occur at around pH 10 if any of the solutions require glutaraldehyde hardening; alkaline post-development processing will occur at pH 8-10 when hardening is not required. If, for some reason, alkaline post processing were to occur at a very high pH, i.e. that of sodium hydroxide, then there might be some potential for damage.

While we're at it- why do we need a fixer that works in less than 5 minutes? I've got enough of this rat race world. I HAVE got 5 to 10

minutes to calmly do a good job. An That's what I want the fixer to

do- a good job. I want it to remove all un-needed silver and prepare my film/paper to be washed. I then want NOT to have to babysit the film through the wash cycle because it is so short and labor intensive. I would rather go slow and make sure I did it right, than hurry up and get @#%$^- up negatives. There- I feel better now!

>While we're at it- why do we need a fixer that works in less than 5 minutes? .... I would rather go slow and make sure I did it right, than hurry up and get @#%$^- up negatives.

 

That's a good point: that accelerated processing as we know it today does demand more attention and intervention than conventional processing.

 

But our rapid processing procedures are unnecessarily messy. There are ways to accomplish rapid processing more easily from the user's point of view. My favourite paper patent is one of Haist's. The paper has a mercaptan-based monobath incoroporated into the paper. After exposure, you merely process it in plain sodium carbonate for a minute, and wash for a few minutes more. It is now developed and archivally fixed. That's all there is to it. You are never in contact with any chemical other than the carbonate. This patent has now expired and, according to Haist, the paper can be (and has been) made in a lightproof garage with ordinary wallpapering tools. The patent is referenced in vol. 2 of his book. I do wish someone would make the stuff!

Bill;

 

You said:

 

"But Kodak's toxicologists believe (as they told me today) that if you swallow glacial acetic acid, you will likely die, because your oesophagal tract will have been burnt out."

 

and:

 

"Ammonium thiocyanate has been shown to cause thyroid damage in humans."

 

FYI, drinking Dektol, D-11, D-19 and quite a few others will do the same to your esophagus due to the alkali and high pH, and you will also suffer probable kidney damage from the HQ and Metol. In addition, the sulfite can cause rapid death if you are one of the people who are allergic to it. Sulfite is also probably a mutagen.

 

You will find sulfites in almost all wines as a preservative.

 

You also find it in all fixes and developers.

 

So why have you not pointed that out to all and sundry Bill? Is it because you just want to target what I say specifically? You ignore other potentially harmful chemistry and only jump on those I mention. How do you rebut the concentration of Kodak Stop bath?

 

The Formulary sells Glacial Acectic acid Bill, and you ignore that. It is not sold by them for professional labs. EK sells the gallon sizes of the acid through local photo stores as well as through the large internet photo companies. EK sells processing solutions containing thiocyanate, and the Formulary sold me thiocyanate.

 

As for the stability of silver images, there is some evidence that the silver image is preserved by the formation of a deposit of sulfides on the surface of the silver. This is anecdotal and not hard evidence, and results from the observations that a little hypo must be left in the coating, hypo decomposes by being oxidized, liberating sulfur compounds, and oxidation is involved in destruction of silver images. Taken together along with finding silver sulfides in the processed films and papers give some anecdotal evidence that silver sulfide stabilizes the surface of a silver image.

 

Along with the fact that toning helps stabilize images, and toning puts sulfur or selenium (as two examples) onto the surface of the silver, then this adds weight to the theory mentioned above.

 

It is for this reason that I don't suggest eliminating hypo completely from a B&W fix, but omitting it from a color fix is more a matter of relative cost and toxicity.

 

As for washing, todays films and papers are considerably different than some of those investigated by Bill Lee. Indeed there have been several generations of gelatin types, hardeners, thicknesses, and emulsion types in the last 40 years or so. There were 3 or more generations of hardeners alone, much less the level changes. There were 2 generations of emulsion types, and at least 2 or 3 generations of addenda in films and papers since the 60s. All of this contributes to the overall swell, porosity, and fixability of a coating.

 

At high pH a coating is far more swollen than it is at lower pH, and the silver-hypo complex is a large molecule. The ammonium salt of the silver-hypo complex is more solubable than the sodium salt which is more soluable than the potassium salt. You cannot fix well at all in a potassium hypo solution.

 

I have no objection to the use of alkaline fixes except for the fact that you substitute the odor and pulmonary problems of acetic acid for the problems of ammonia, neither of which are not friendly to lungs. My fix is formulated to eliminate both odors, acetic acid and ammonia.

 

Historically, ammonia fumes have been found to be much more toxic than acetic acid fumes all things being equal, due to the fact that acetic acid is well tolerated by the human body, and ammonia is less so being a base which reacts more strongly with proteins. Deaths due to ammonia fumes have been reported, but I know of no deaths from acetic acid fumes. In any event, the point is moot with my fix as there are no fumes at all.

 

If you don't like using thiourea or thiocyanate, then just use plain ammonium hypo (60%) at 200 ml / liter and ammonium sulfite at 10 g/l adjusted to pH 6.5 with 28% acetic acid. Use a slightly longer wash time than with TF4 or use a hypo eliminator.

 

Now, please take note of this. It is finally time for me to bring this to the attention of everyone! I recommended 28% acetic acid, and throughout this entire thread Bill Troop has discussed Glacial Acetic Acid and taken exception to the fact that I have recommended its use. You know what? I cannot find a single statement I made here in this thread where I suggested that it be used! In all cases, I used 28%. I have merely stated that it is still SOLD and I made that statement only to answer Bill Troops comment, but I never suggested that anyone use it here for adjusting pH. In fact, as far as I can find in my perusal of this thread, Mr Troop was the first person to bring up the subject of Glacial Acetic Acid.

 

Therefore, it appears that this entire discussion has been meaningless, as I never suggested the use here of glacial acetic acid. Sorry Mr Troop. Better read what I write next time.

 

Ron Mowrey

Ron, thank you for your informative post. I just want to clarify a few points:

 

>How do you rebut the concentration of Kodak Stop bath?

 

I don't rebut it, I point out what ideal practice is.

 

>The Formulary sells Glacial Acectic acid Bill, and you ignore that.

 

Ron, I have no connection with Formulary other than that they sell some products I formulated. I can't control what they sell. In fact, I don't even know what they sell, outside of my products.

 

>As for the stability of silver images, there is some evidence that the silver image is preserved by the formation of a deposit of sulfides on the surface of the silver. This is anecdotal and not hard evidence, and results from the observations that a little hypo must be left in the coating, hypo decomposes by being oxidized, liberating sulfur compounds, and oxidation is involved in destruction of silver images. Taken together along with finding silver sulfides in the processed films and papers give some anecdotal evidence that silver sulfide stabilizes the surface of a silver image.

 

Ron, you use the word 'anecdotal' twice in this paragraph. That evidence isn't anecdotal, it is published. Let me refer you to the SPSE International Symposium on the Stability and Preservation of Photographic Images which took place August 29-September 1, 1982, at the Public Archives of Canada. Klaus Hendriks was the General Chairman of the Committee. Session 5 was Stability of Photographic Silver Images.

 

Drago and Lee read two papers; there were also papers by Beveridge and Cole at Ilford, Minigawa and Torigoe at Fuji, Tullis at Polaroid, Kopperl and Larson at Kodak, and finally Owebach at Kodak. As far as I know, most or all of these papers were subsequently published in journals. The evidence presented was not anecdotal. It was as factual as the science of the day could make it.

 

I would further point out that Lee described the use of Kodak Rapid Selenium Toner as desirable. Let us not forget that KRST is not just a toner, but is also an alkaline ammonium thiosulfate fixer. Lee also noted that 'the use of Kodak hypo clearing agent to reduce washing time is less desirable than using the full wash period', which goes to Garry's point.

 

The gist of several of these papers is that some thiosulfate residual is desirable.

 

What will particularly interest you, Ron, and is very on target for the discussion of your fixer, is the following remark of Ilford's Berveridge and Coles:

 

"Analytical examination has shown that processing in a thiosulfate fixing bath provides a silver sulphide surface considerably improving the image stability. Compounds such as thiourea reinforce the sulphide layer and give further improvement to image stability, however, formation of sulphide from this source does not occur during processing but subsequently by decomposition of the adsorbed compound."

 

My points are two: thiourea, at least according to the Ilford scientists, appears to assist in stability in a manner that you may not have been aware of and I must certainly admit that I had completely forgotten this; and the evidence is not anecdotal. These papers were read at an SPSE conference and whether they were subsequently published or not, their findings are not anecdotal.

 

>As for washing, todays films and papers are considerably different than some of those investigated by Bill Lee.

 

Especially given that he was primarily working with spectroscopic plates. However, he believed that his results were extrapolable to most b/w photographic materials and most subsequent readers of his papers have accepted this. That does not address, however, the question you raise, which is, have materials changed so much in the 20 years since then that previous findings have been invalidated? I would guess no, but the fact is, we simply don't know, unless someone has got an awful lot of great information up his sleeve that he isn't publishing. Considering how expensive it would for any company to research this matter adequately, I am inclined to believe that the research has not been done. But I don't know that for a fact.

 

>... All of this contributes to the overall swell, porosity, and fixability of a coating.

 

Has anyone studied how this might affect image permanence? Note that Zawadzki and Dickerson tested the new emulsions from Kodak and found that functionally they were similar to the old ones, in that development times did not change significantly.

 

>You cannot fix well at all in a potassium hypo solution.

 

You will recall how that discovery in the 1930s led Edith Weyde to her discoveries in diffusion transfer photography, a topic I very briefly note in my book.

 

>I have no objection to the use of alkaline fixes except for the fact that you substitute the odor and pulmonary problems of acetic acid for the problems of ammonia, neither of which are not friendly to lungs.

 

That is an excellent point. The pH has to be controlled very carefully to make the product usable. Please note that because of the evolution of ammonia fumes, the simple alkaline fixer I published in FDC is recommended only for films in closed tanks.

 

>My fix is formulated to eliminate both odors, acetic acid and ammonia.

 

That is truly desirable. Personally, I would prefer some ammonia odor in exchange for the drastically reduced washing times. Others will, as you say, prefer a truly odorless fixer and it is unquestionable that the pH neutral odorless fixer which does not evolve fumes is safer in open trays in the typical darkroom.

 

>Historically, ammonia fumes have been found to be much more toxic than acetic acid fumes all things being equal

 

I don't think that can be argued.

 

>If you don't like using thiourea or thiocyanate, then just use plain ammonium hypo (60%) at 200 ml / liter and ammonium sulfite at 10 g/l adjusted to pH 6.5 with 28% acetic acid. Use a slightly longer wash time than with TF4 or use a hypo eliminator.

 

I object to this only on the grounds that I believe it is well established that the wash time, sub-alkaline, is not just slightly longer, but dramatically longer, and I encourage you to test this; I would also point out if it really is true that thiourea improves image stability, then why shouldn't we use it? Now I realize that much of what Ilford has had to say about fixers has not been accepted by the Kodak community by and large. Part of that is due to the Not Invented Here syndrome, but part of it is simply that Kodak had about a million more and largely better scientists. I would like to know if you or anyone else at Kodak investigated thiourea in this respect, and what your conclusions were. That is to say, not in its capacity as a fixer accelerator, but in its capacity as an archival stabilizer when used as a constituent of fixers.

 

>Now, please take note of this. It is finally time for me to bring this to the attention of everyone! I recommended 28% acetic acid,

 

I did see that clearly, Ron, and I really appreciate it. I should have said so explicitly, and I apologize for that. My comments were really in reaction to the previous thread, and though that is blessedly closed, there does seem to have been some 'carryover', if you will permit the use of the term in this context.

 

Minor stuff- I think people are bothered by different smells. Working strength stop bath doesn't bother me at all. Fresh powdered fixer (mixed) catches in my throat and is really annoying until it gets used a bit. The slight ammonia odor of TF4 is just enough to let me know it's not the developer :-) but I find it in no way bothersome. I tried isoproponal in one of my paper developers, and can't recommend that at all. Tank use only. Yecch. Like Garry, I don't worry much about processing time, especially with film. The big time sink in my darkroom is printing. Though I don't believe in super long paper development times, I want a good 1 1/2 minutes. It seems that the cycle time for test strips, work prints, and fine prints (if anything I've ever printed even deserves the name), is too long. Maybe I'm spoiled by computers, but if I can do a few decent wet prints per hour, I'm really on a roll. A process that only speeds up fixing and washing doesn't match up with the rest of my workflow. TF-4 is plenty fast enough, as are the resulting wash times. As I mentioned above, my only complaint is the purple dye found in some Kodak films. This seems to be more efficiently destroyed or washed out in conventional fixer, along with certain developers like Rodinal. The worst possible choice for Plus-X is my preferred combination of FX2 and TF-4!

Bill;

 

Any 'carryover' was entirely yours. Thank you for clarifying that for the readers.

 

It seems we do agree on some things. You see, we each can learn from each other. I'm happy to admit that. However, I'm surprised to see you think that I was unaware of the facts you have posted. I knew Bill Lee and Pete Drago both. Bill Lee once offered me a job in his project, as a matter of fact, but I preferred color work.

 

I know many of the people you cite and have gotten much information from them directly which I am sure that they could not share with you due to its proprietary nature.

 

The patent by Mowrey, Stephen, and Wolfarth is based on much information we learned on fixing and bleaching. The followup by Stephens and Surash is the culmination of my work, reducing it to a liquid kit which sold for nearly 20 years as the Ektaprint 2 bleach fix. Their methodology was unique, and I had the honor of showing their first liquid kit to Dr. Paul Vittum, head of the Color Photography Division.

 

My original formula was completed in 10/1966, and the first color paper blix was known as the 1066 blix at EK. It went on sale in 1970 and the patent we worked on during development of the bleaches and fixes issued in 1972. If I had gotten 1 penny from every gallon of blix sold, I would be quite wealthy by now.

 

We eliminated thiourea and thiocyanate from the paper blix due to the fact that a high potentcy blix was not needed for paper, but it was considered by Edens in his work on the C41 bleach and fix. Finally, the RA C41 solutions were based on Edens work supplemented by Stephens work and the follow on work after Keith died (of natural causes not chemicals). Thiols and thio ether accelerators or fixing agents were eliminated also, until recent changes added several proprietary fix and bleach accelerators, as well as using new iron complexes to reduce BOD and COD.

 

I used the word anecdotal, in the sense that it was a private communication to me rather than through the journal articles, and I have more information than is published. I don't feel free to disclose the data, as I am not sure what was published and what was not over time. I have had round table meetings with Lee, Henn, Haist, and King among others to review the progress of our work on the patents that Grant, Jim and I share. In those sessions as well as meetings with Surash, Wolfarth, Stephen and a host of others, we planned a strategy for overall fix and bleach work for color and B&W products. All the while, Lee and his team worked on fixes for B&W.

 

Prior to Stephens work and the work of his group, there was a group under Frame and Wissell. Did you know of them? Frame left EK, and Wissell died tragically setting the stage for future work by Stephen.

 

The reason I bring this all up is to point out that there is a whole body of proprietary information that I am privy to that you have no idea exists, and that was never published. I also have insights into the work and the direction of work over 3 decades of development of B&W and color fix and bleach solutions. Even after I left the area, I would be interviewed by new people joining the bleach - fix group so that they could gain insights into my thinking on this subject.

 

I could list a half dozen people or more that worked in this area that never published and worked on things that never became products, or found specialize niches in the processing of films and papers.

 

I was disturbed by your complete dismissal of the knowledge that I have and the insights that I have gained, and the words you used to dismiss them.

 

The Mowrey, Stephen, Wolfarth patent # is 3,706,561. I don't have the # of the Stephen and Surash patent. In our patent, we list fixing agents and fixing agent combinations that act synergistically, including thio ethers. It may interest you. Some of them are totally harmless to human beings, plants, and animals. Some of these will not biodegrade or oxidize and therefore would build up in the environment. I worked closely with our Health and Safety labs on these chemicals Bill. I was a human test bed, having blood tests every 6 months while I worked with this chemistry and for 20 years afterwards.

 

It was due to my extensive process development experience, particuarly in color, that Grant Haist asked me to help him edit his book. That fact alone should have some significance for you. I suggest that you consider it carefully before you dismiss my work and career so cavalierly.

 

I mentioned the Formulary sale of Glacial Acetic Acid merely to indicate that they sell it to amateur photographers.

 

Ron Mowrey

>It seems we do agree on some things. You see, we each can learn from each other.

 

There will inevitably be clashes between those who focus very widely, for range of knowledge and those who focus very narrowly, for depth of knowledge. Each type has value, but they are polar opposites.

 

>I am sure that they could not share with you due to its proprietary nature.

 

My experience is that if you know the right question, you'll get the right answer, but you do have to know the question and your interlocutor has to be in the right mood.

 

>I was disturbed by your complete dismissal of the knowledge that I have and the insights that I have gained, and the words you used to dismiss them.

 

Oh well, same here.

 

>The Mowrey, Stephen, Wolfarth patent # is 3,706,561. I don't have the # of the Stephen and Surash patent.

 

I wish you could dig up that number somehow. The US PTO website is set up such that you can't search for authors before 1976, and Surash is only listed as the inventor of 3 patents after 1976 - there must be many dozens before that point as his name is always coming up.

 

>It was due to my extensive process development experience, particuarly in color, that Grant Haist asked me to help him edit his book.

 

It IS mightily impressive - in color.

 

>I suggest that you consider it carefully before you dismiss my work and career so cavalierly.

 

Like I said, when you get two guys in the same room, one of whom knows everything about a few things, and the other of whom knows a few things about everything, sparks must fly. Naturally, the admiration of the generalist for the particularist is unbounded, because the generalist knows he can only get the information he needs from the particularist.

 

>I mentioned the Formulary sale of Glacial Acetic Acid merely to indicate that they sell it to amateur photographers.

 

Shocking! I wouldn't do it myself. But I have got to the point where I really don't like to be around chemicals and have adopted something of an extremist safety position. That said, I think we struck a reasonably good balance in FDC between both sides. I had a very hard time convincing my co-author to use neoprene gloves, but he likes them now, and as for publishing Richard Henry's idea that you should dissolve a packet of, for example, developer, by opening a corner, then submerging the corner in water and emptying the packet that way, he said it was impossible to do, until he tried it, and now he likes it. Now, I can't expect you to sympathize with that viewpoint, but I think it is the most responsible viewpoint to take as far as public utterance goes. Yet, on the other hand, in perfect fairness, I have heard more than one long-lived chemist say that he believed he was alive because the horrible chemical exposures he suffered from a lifetime of work must somehow have boosted his immune system. The idea being that a sub-lethal dose of the poison can strengthen you. Now that really is anecdotal persiflage, but I have heard it from several reasonably distinguished chemists. So there one is.

 

One final point, if you look at the arguments here, you'll see that a lot of it is due to three simple facts: (1) my focus is black and white; (2) your focus is color; and (3) black and white films have never been as well-hardened as color films so that experiences in extreme solutions can be quite different. (It is also likely that some of the films available today from non-major sources are still hardened with 1950s level technology.) Haist often bemoaned the fact that black and white films were not hardened adequately; he believed that hardeners in processing solutions should never be necessary. Now we all know that since the 1980s, black and white films _are_ much better hardened than they were. But I would be very surprised to find that they were hardened as well as color films. Do you have anything you can say about that with regard to hardening when comparing the latest generations of black and white films with their color counterparts?

 

Relating also to hardeners, could you say anything about the syndrome where users of pyrogallol and pyrocatechin have had more than their fair share of reticulation-like experiences, especially when not using distilled water? Haist has very generally and preliminarily theorized that this could be due to interaction with the hardeners used in the films. If I remember what he said correctly, it was something very general about the 'broad molecular structure' of those particular developing agents.

Bill;

 

Just for the record, color and B&W are closer than you might imagine. I don't expect you to believe that, but some examples might help. Color and B&W products use the same hardener, at the same level, except for X-Ray. (we discussed that before)

 

The gelatin is the same in both films. Emulsions are similar, but not identical, nor are silver levels or addenda. In fact, color films can be softer than B&W films. Gelatin levels and therefore thickness and swell are very much higher in color materials.

 

This impinges on the difference between swell and hardness which sometimes go together and sometimes do not. Swell is often necessary to improve density in B&W films, but not in color. Many engineers have had a hard time separating out these two things (measurement wise) even though they can understand them from a materials handeling and engineering standpoint.

 

Pyrogallol and pyrocatechin are hardeners themselves that give a relief image and can act to distort (reticulate) the image due to an extra hardening effect. The relief image can stress and crack an image badly under certain circumstances. I have seen cross sectioned pictures of that published somewhere. I'll try to locate it and post it, but I think OTOMH that it was in Ctein's book, "Post Exposure".

 

If you want more information, just let me know.

 

Ron Mowrey

Bill;

 

Sorry, the reference was not Ctein. His comments were directed towards the sharpening effect of the relief image in color materials. I have seen it somewhere, but I have so many photo books (except Haist - sorry) it will take me a while to locate it.

 

I think you have a mistaken impression about me. Just because I disagreed with a few things in your book, I don't denigrate your achievements. What brought this thought home to me was the fact that the Ctein book was on my bookshelf right next to A&T.

 

Ron Mowrey

Bill;

 

The illustration of rupture of emulsion with pyrogallol developer (reticulation) is shown in fig 396C, Page 1040, Mees "The Theory of the Photographic Process" Revised edition.

 

It can be decreased by slowing the drying, as this effect is caused by the rapid drying of the less swollen areas of the emulsion due to the tanning effect.

 

Ron Mowrey

>Just for the record, color and B&W are closer than you might imagine. I don't expect you to believe that, but some examples might help. Color and B&W products use the same hardener, at the same level, except for X-Ray. (we discussed that before)

 

I do believe it, since you put it that way, for Kodak films, and I am glad about it. Have you any idea if that level of hardening also applies to non-Kodak b/w films? I get the very general impression that Agfa and Ilford films are now hardened much better than in previous decades, but what about the Eastern European and other films of that ilk? I realize that such information if it is known might be considered quite confidential, but equally, it would not surprise me if nobody at Kodak actually had it.

 

A separate issue, given the quality of present day hardening of Kodak black and white films: what would you say would be the maximum, not just safe but desirable, processing temperature without additional hardening?

 

>Pyrogallol and pyrocatechin ... relief image can stress and crack an image badly under certain circumstances.

 

Can this exist at a point where it is not necessarily evident by visual examination of the negative but where an enlargement is not usable?

 

>The illustration of rupture of emulsion with pyrogallol developer (reticulation) is shown in fig 396C, Page 1040, Mees "The Theory of the Photographic Process" Revised edition.

 

That is fascinating. I can't look it up as I have just packed up

most of my books preparatory to an unexpected move. Are you referring to the 3rd edition of 1966? (I am guessing that; I think the 4th of 1977 no longer has Mees's name.) I wonder if Gordon Hutchings is aware of that. I think that's one thing he might have missed although he has studied closely nearly everything that has ever been published on tanning development.

 

>It can be decreased by slowing the drying, as this effect is caused by the rapid drying of the less swollen areas of the emulsion due to the tanning effect.

 

Can you suggest a way of accomplishing that in an ordinary darkroom? That is to say: is there a practical way in which we can dry film slower than by just hanging it up at room temperature?

 

I suspect that many of the recticulation or reticulation-like effects I have seen in tanning developers can be avoided by using distilled water; in other words, that too rapid drying is not the cause in many of these cases and instead is due to some unknown reaction between the chemistry and minerals in whatever tap water is causing the problem. But I still occasionally hear of an obstinate case and now wonder if it would not be good practice to advise some method of slower drying when using tanning developers. Needless to say, no manufacturer today could be expected to make a film with tanning development in mind. Perhaps your suggestion is the key to the few remaining obstinate cases where reticulation is still sometimes experienced with tanning developers?

 

Finally, here's a question you might know the answer to, or might be able to pose to W.E. Lee if he is still alive. In 1982, he stated publicly that he was working on a fixer that would promote improved stability of black and white materials, and that the formula for the fixer would in due time be published. As far as I can recollect, that formula was never subsequently published, for whatever reason. It would be interesting to know more about this. Did the work pan out in an unexpected direction? Did it have to be terminated before it could be completed? It's a tantalizing puzzle - unless of course, the formula was published and I simply missed it.

Bill;

 

As far as I know, Fuji uses a hardener that is totally different than the EK hardener(s). Fuji used a heterocyclic chloro compound, the last I knew from reading patent literature.

 

Ilford film and Fuji film are the only ones I know that are similar to EK film in hardness and in relative swell. I have not used EFKE personally but my readings and knowledge suggest that they use some of the previous generation of hardeners and therefore will not stand up to the same temperature or handeling of EK, Fuji, or Ilford films. Some off manufacturers license hardeners from the 3 major companies IIRC.

 

The highest temperature I ever processed at was 120 deg F. There were no scratches or emulsion problems. This was a pure experiment though, so I have no idea how it would work in the real world. It was done with color materials, so I assume that B&W products would work as well. I do want to distinguish between hardness and swell again. B&W materials are designed to swell more than color materials on a wt/wt basis of gelatin. This is due to the morphology change of the silver metal and its internal forces on gelatin. It expands outward in filaments or in tablets, distorting geltain. If restrained in the way it 'moves' the color or tone of the image is off. I cannot go into more details on this, but X-Ray is one good example. I can say this: 100 mg/meter sq of silver metal can appear to have any density from say 0.1 to 3.0 depending on the covering power (that is merely intended to serve as an extreme example, not an exact set of figures and I certainly don't remember my exact data). I have personally measured this in B&W materials using x-ray fluorescence to quantize silver levels after development. Of course, in color, this is not a significant problem at least as long as it does not interfere with developability or diffusion of oxidized color developer.

 

The copy of Mees that I have is dated 1954. Jack Thirtle gave me a copy shortly after I joined the company, and it was one of the older editions, as you see. I could scan in the page, but am not too sure of the right to do this due to the copyright.

 

This property of emulsion cracking or 'reticulation' was long known and was of general concern as hardeners become more and more effective. Any interest in the cracking was abandoned with the decrease in interest in PMK type developers a few years back. Maybe it should be re-visited in light of their 'revival', but I doubt if it ever will be as it is a very small market. It is not really reticulation, but is more like the cracking of mud as the water content evaporates, which leads to cracking and crazing.

 

If the cracking occurs regularly along image lines, it acts as a sharpness enhancer. That is what Ctein discusses and how I got the two references mixed up at first. If it occurs non-imagewise, then the image is effectively ruined above a certain magnification. It can be reduced or eliminated by slow drying. Heat during drying would appear to me to be the worst case with PMK developers. Slow cool drying conditions with mild RH, say 50% would be best IMHO.

 

The use of distilled water or the effect of salts on this drying phenomenon has not been studied AFAIK. I can't help you there.

 

I know of several Bill Lee formulas, as all of us were working with similar chemistries, but none that I would care to discuss due to two reasons. One is that I am not familiar enough with them to do them justice, and the other is that I believe that they are proprietary.

 

The only person I know who might have information on the fix is Dorsey Dickerson. He and Bill worked closely together for some time IIRC. The other person is of course, Grant. I worked with some of the thoethers and other compounds along with Grant, and they are fully disclosed in our patents. However, we focused on heat activation as you may remember, and dry processing.

 

I have not seen Bill Lee in over 10 years. I have no idea if he is still around. I just looked him up in the retirees database and he is not listed. This just may mean that he has not supplied our webmaster with information. Dick Dickerson is listed and he has published his e-mail, so you might consider contacting him.

 

I hope this helps. I will answer your questions as far as I can.

 

Ron Mowrey

Just as a matter of interest:

 

The flash point of propylene glycol is indeed 99 C. At that point it will support combustion. The boiling point is 188 C. Density of the vapor is 2.6 times that of air. The autoignition temperature is 425 C (779 F).

 

I shall test the flammability of hot propylene glycol by attemting to ignite it at a temperature of 250 F with a flame near the surface. If I am still alive tomorrow, I will report the results.

 

As I am sure you all know, the white vinegar sold for canning and other purposes at your grocer's is 5% acetic acid. You could probably distill that down to 28%.

And if you capture the water, you could use that to dilute it back down to stop bath strength!

>And if you capture the water, you could use that to dilute it back

 

>down to stop bath strength!

 

Or to mix the water with with the acid and a little oil for your salad.

Well, I'm still here.

I put 100 ml of propylene glycol in an 8 oz Pyrex measuring cup. Heated it for 1 minute at full

 

power in my microwave, bringing temperature above 220 F. I removed the cup to a place near the

 

water faucet and used a piece of rolled up paper as a wick to ignite the glycol. The flame had to

 

be fairly close to the surface of the glycol. There was no explosion, the flame did not get much

 

higher than the rim of the cup, and it was easily extinguished by smothering it with a loose

 

fitting pot lid.

 

I conclude that an open flame or electrical spark would probably ignite the glycol when it is

 

over 100 C, but no explosion would result. The boiling point is well above the temperature I

 

recommended for dissolving ascorbic acid, and the autoignition temperature is more than double

 

the boiling temperature. I think lower temperatures could be used if I wait long enough or stir

 

hard enough. Viscosity and resulting sluggish molecular motion slows solution.

 

I did mention the possibility of danger in my original article in Photo Techniques. I should not

 

have to repeat the complete text of that article each time someone asks for a formula.

 

As to authority, we used to say at NASA that an authority is one who learns more and more about

 

less and less until he knows all there is to know about nothing. He is a relative of the Key

 

Bird, which flies in circles of ever decreasing radius until he sticks his head up his own anus

 

and cries"Key-riminy it's dark in here." Joking aside, I believe that the person who presents

 

verifiable experimental results is an authority with regard to those results, even if those

 

results do not agree with the opinions or extrapolations of other authorities. In any case, I

 

propose that we are not participating in this forum to establish or disestablish authority, but

 

to request or to pass on technical information.

Patrick;

 

I'm glad the experiment turned out the way it did.

 

I have a fear that it might happen differently in the following scenario.

 

100 ml of propylene glycol in an 8 oz container or larger, on a stove, done by someone with no microwave, and as the temperature rises towards 220, the vapor displaces the air in the container, rises over the edge and being heavier than air drifts downward to the flame or hot electric element or plate.

 

At this point, you have about a 4 oz volume or more of vapor in the container mixed with some air and more over the edge moving downward. It can ignite with a flash rather like cooking oil that is over heated. This is my fear, and it can happen with gas or electric stoves. Since fires with cooking oil happen occasionally, then a fire from propylene glycol is a distinct possibility, especially with such a low flash point wrt boiling point.

 

Since the density is near 1.0 then about 74 ml of propylene glycol can generate over 22 liters of vapor at that temperature. Therefore, as you raise the temperature, quite a bit of vapor is possible, and an accident might happen to the untrained or careless.

 

Since I know personally of two severe fires from cooking oil, and several more in the lab, I am rather conservative on this matter, as the individuals concerned were very careful, but accidents do happen.

 

Ron Mowrey

That is another possibility that I covered in my original article. I used a gas fired kitchen oven set at 250 F to heat a quantity of propylene glycol with no untoward events. Even though the flame is below the container of glycol and could conceivably ignite the glycol vapor, at 250 F the vapor partial pressure is very low. The boiling point is about 370 F. If anything boils off, it could be an alcohol which might occur as an impurity in tech or commercial grades or it could be water vapor for which the glycols have an attraction.

 

My main point is that I did point out possible hazards in the original article, which nobody in this thread seems to have read.

Patrick;

 

Yes, you have mentioned it several times here, but people seem to continue to make posts as if they were ignorant of the basic warnings you have made right here on PN. I have been unable to read them myself and have had to rely on your internet posts myself for this information.

 

I was partly prompted to make this post, as a family member had a severe house fire when simply melting paraffin for covering her jelly. She did this every year for decades with total safety. Even though a solid at room temperature, it flashed on her, and she had a kitchen fire (I don't know the flash point of paraffin). And, one of our chemists experienced an unexpected flash fire from ignition of vapors of a high boiling material.

 

In a chemistry lab, heating organic materials in the open is avoided unless there is a good hood which sweeps any vapors upwards away from the heat source. Even so, I have heard of fires in hood ventilation systems.

 

In view of Lex's warning at the head of this thread, about a chemical mixture that is used for the most part commercially, I felt it useful that we have mentioned several safety issues again here.

 

The PMK information above may also be of interest to you. I think that Bill has made a very important point about the overhardening and apparent reticulation possible by using those developers.

 

I am planning on using a TEA EAA developer for my cross process of color paper. I may use one of yours. I'll let you know how it works out.

 

Ron Mowrey

IIRC, my mother used a double boiler to heat the parafin. It might not be a bad idea to use one for the TEA and Glycol as well. At least you are assured of a temperature not much higher than 100 C until the water runs out. It will only build up a little pressure in the lower pan.

Patrick - a double boiler would go a long way towards making this a safer procedure - but it may have some issues with the extra moisture around from all the steam the double boiler would make. I'm sure you'll test for that!

 

My concern with using the microwave for heating solutions is if someone is a smoker, and pops the door open after heating some glycol or TEA in it, and places their face (and cigarette) near the microwave oven door. It could be possible to have a flash from solvent vapors in that situation. It may only result in a lot of singed hair, but certainly it could be worse. And if the microwave made a spark, it could cause more damage.

 

I used do the flashpoint anaylsis test at work - both open and closed cup, and while it is actually kind of fun to get things to flash, it's with pretty small volumes of air, and I was expecting to get a flash. The vapors conatined in the couple of cubic feet of a microwave would be a different issue.

 

I'm not saying this technique should not be used, but just that some issues with it needs to be mentioned and considered.

There's another issue: I've seen arcing in the waveguides of microwave ovens when the e-field strength climbs too high in a spot... In fact, it happens in my own combo convection-microwave oven when the temp gets above about 400 degrees! :(

 

Back on 26 October Kirk Keyes wrote:

 

"My concern with using the microwave for heating solutions is if someone is a smoker, and pops the door open after heating some glycol or TEA in it, and places their face (and cigarette) near the microwave oven door. It could be possible to have a flash from solvent vapors in that situation. It may only result in a lot of singed hair, but certainly it could be worse. And if the microwave made a spark, it could cause more damage."