The truth about Clayton fixers?

[bill_troop1]

I noticed in a recent thread called 'fixer of choice?' that Lowell

Huff claimed Clayton's CP fixer will clear film in 15 seconds or less.

 

I thought this was impossible, and decided to put it to the test.

 

I took some 2" strips of T-Max 400 (a little old, circa 1997) and

processed it in fresh CP Fixer, mixed according to directions, and in

my own TF-4 fixer, mixed according to directions.

 

TF-4 cleared the film in 30 seconds.

 

Clayton CP Fixer cleared the film in 2 minutes, 45 seconds, or 165

seconds.

 

In other words, Clayton CP, according to my test, is about 5 times

slower than TF-4, and about 10 times slower than it claims to be.

 

This is what I would expect for a relatively primitive powder formula.

 

Has anyone got any other results/comparisons tabulated?

 

A side note: TF-4 really does remove a considerable amount of the

magenta dye.

 

N.B. I processed with dry film. Results with wet film, or processed

film, should differ, but not substantially.

 

I intend to do some more extensive testing as time allows, with

different films and different pre-treatments.

 

But I don't see anything that could possibly support Lowell Huff's

extravagant claims about this product.

 

Lowell - have you actually tested this stuff? Would you care to

publish some results? It would especially be interesting to see the

results of your tests when compared to TF-4.

 

I would be interested in hearing from anyone who has actually tested

film (and also paper) clearing times with Clayton fixers.

[jay_de_fehr]

Bill,

 

if TF-4 clears TMY, a notoriously difficult film to fix, in 30 sec., what is the recommended fix time for TMY in TF-4? If we use the old rule of 2X clearing time, that would suggest a 1min fix time. Is this correct?

 

Jay

[john_finch]

Jay,

A fresh fix bath can often clear a film in 30 seconds and I have used the 2X rule myself with no apparent detrimental effects for 30 years. What's wrong with 1 minute fix if the film was clear after 30 seconds? Do you think it too quick and if so why?

[al_divenuti]

Bill-

 

The claim is absurd, but I don't know if it's intended to be misleading. There's a lot of data that's published by Clayton that seems absolutely ridiculous on inspection.

 

I recently got my hands on some Clayton F60 (it's actually a very nice developer - but that isn't really the point). Clayton publishes a time of 6.0 minutes for an ASA/ISO of 400 with processing at 20 C. Believe me, that gives intolerably flat negatives even with a condenser enlarger. Even stranger it suggests a time of 5.5 minutes at 24C. That difference is awfully small for a PQ-based developer and indeed, when I tested it on a 2nd roll of Tri-X I found that the negatives were almost normal contrast. A 3rd roll processed at 20 C for 9.5 minutes was almost perfect.

 

I don't know if Lowell is the source of this data so it's probably unfair to blame him - but it's got to be in Clayton's best interests to conduct more accurate and thorough testing. Unless they have been conducting these tests while traveling at relativistic speeds, their claimed times are just plain wrong.

[jay_de_fehr]

John,

 

I have no problem with a 1 min fix time, in fact I prefer it to a longer time. I have been using Ron Mowery's Superfix, which fixes HP5+ in about 40-50 seconds, and I thought that it was substantially faster than TF-4. It's good to know there's another option for rapid fixing. At what PH does TF-4 work?

 

Jay

[bill_troop1]

>if TF-4 clears TMY, a notoriously difficult film to fix, in 30 sec., what is the recommended fix time for TMY in TF-4? If we use the old rule of 2X clearing time, that would suggest a 1min fix time. Is this correct?

 

Jay, the time I gave was for dry film. Clearing time for wet film

would be a few seconds longer. With Tmax films, you generally leave

it in the fixer a little longer to remove more of the dye. I recommend

twice the clearing time for ammonium thiosulfate fixers. For

sodium thiosulfate fixers, used with modern films, I recommend

3 times the clearing time. That means the recommended fixing time

for TMAX 400 in Clayton CF would be 9 minutes. And that's only when

the fixer is fresh. Fixing time increases as the fixer is used up.

[edward_zimmermann]

"<cite>What's wrong with 1 minute fix if the film was clear after 30 seconds? </cite>"

<P>

Nothing. In fact clearing time is nearly sufficient fixing time. The reason for the 2x is to project enough headroom for fixer capacity and to allow for lower replenishment rates. Since in our amateur darkrooms we tend to use our fixers only to a fraction of their capacity--- many even one-shot--- one could through some tests arrive at much shorter fixing times than the popular 2xclearing times. This is significant as it reduces the washing times and ultimately increases image permanance. Weighing in on the other side, however, is the observation that slight over-fixing is harmless (with appropriate washing) but under-fixing long-term catastrophic. The goal then is to fix as short as possible but to err on the side of long and <strong>never</strong> too short.

[bill_troop1]

>I don't know if Lowell is the source of this data so it's probably unfair to blame him - but it's got to be in Clayton's best interests to conduct more accurate and thorough testing. Unless they have been conducting these tests while traveling at relativistic speeds, their claimed times are just plain wrong.

 

Al, you're absolutely right that Lowell isn't the source of

the data. But he is the source of the claim. May 10, 2005,

this forum,

 

"The interesting thing about our powder fix (CP FIXER) is that it will clear film in 15 seconds or less."

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00C8Xl&unified_p=1

 

I'd sure like to hear from Lowell with some test results.

[jay_de_fehr]

I've never seen Lowell ignore a thread with "Clayton" in the title. I"ll watch with interest.

 

Jay

[edward_zimmermann]

"<cite>Al, you're absolutely right that Lowell isn't the source of the data. But he is the source of the claim. May 10, 2005, </cite>"

<P>

I would not take anything Lowell says seriously. Many of his claims have violated natural laws... Believing almost anything he says seems to violate the rules of common sense. You did not have to test anything to know well that NO stable powdered fixer (Ammonium thiosulfate crystals are ill-suited to commercial developers) can clear TMax-400 in 15 seconds. Given the problems of Ammonium chloride and the popularity of stainless steel tanks I'd guess they are selling a Ammonium Sulfate/Sodium Thiosulfate based fixer--- and hearing about their other products probably an ordinary one based around Kodak's F-9.

[john_finch]

Edward,

Thanks, I agree that 1 minute is not too short if it is X2 the clearing time also have always been happy to err on the side of safety, at least by a small margin.

 

Jay,

TF-4 is an excellent fixer which I use exclusively for films. Fast, efficient and safe for tanned/stained negs. I don't see any point in having different batches of fix for different films as I'm sure you would agree. Everyone to their own but I am very happy with this fix indeed.

 

As far as TMax films. Never liked them. Thank goodness for Delta.

 

One thing that Bill might be able to answer. Why do acid rapid fixers bleach negs with very extended fix times where alkaline fixers do not? If it is the Ammonium Thiosulphate then would they not both do the same damage? Is it another chemical that is doing the bleaching? Or is there no evidence of this effect - perceived wisdom?

[kirk_keyes]

HI Bill,

 

Perhaps you are not testing the same film as Clayton did to come up with that claim? As you know, different films have different fixing times.

[User_502260]

I use many different fixers and they all work well for what they do. I have never used the CP fixer in question. I agree that the T-MAX type films are much harder to fix and wear out the fixer faster. If you want to see fixer clear a film in only seconds try fixing Kodak Technical Pan or Kodak Imageline HQ microfilm. Almost any fixer will clear these films right away. Fresh fixer will also clear Ilford Pan-F Plus very quickly.

 

My favorite fixer for printing is Clayton Odorless Fixer. For film I like Heico NH-5 with hardener. I also have Kodafix, Ilford Rapid Fixer and some Agfa fixer on hand and they all work. All of the rapid fixers seem to work equally well with film. Using standard fixer with T-MAX type films will require more patience and is not a good idea if you mostly use this film type.

 

The issue of permanence is something I have been thinking about. If you are at least 50 years old and one method of fixing and rinsing will get the negatives to last 40 years while another will only get it to last 30 years, will this matter? I use Perma Wash in the rinsing process and I hope my negatives last a long time but I have to wonder how many young people are actually developing black & white film themselves. It is possible that in the future my son will take in ineterest in my negatives and will want to view them or make prints from some of them if this is still possible. For many people who are 50 or older (to pick an age) the enjoyment they get will come from looking at the prints they make now and not from the knowledge that their negatives may last longer than anyone will be interested in them.

[lowell_huff1]

Hello Mr. Troop:

Thank you for questioning and testing my claim of clearing time for our CP Fixer. This gives us an opportunity to agree on some definitions.

? CLEAR: The complete removal of exposed silver from the emulsion. Lets not confuse ?clear? with ?dye removal.?

? FILM CLEARING TEST: 1) Daylight a piece of film. 2) Wet the film with water and squeegee it. 3) Swirl the film in working strength fixer until you can see through the base, noting the length of time to accomplish a clear base. The obvious reason that this test is done only with film is that paper does not show clear.

? HYPO: A common name for a SODIUM THOSULFATE fixer.

? RAPID FIXER: Almost exclusively an AMMONIUM THIOSULFATE agent with a reduced pH which accelerates the fixing process.

? DIFFICULT TO FIX: I don?t know what that means or how it is scientifically measured? If this is the dye removal issue then there are films that take longer to remove the sensitizing dye. It is the sodium sulfite in the fixer that removes the dye. As it is depleated, it does take longer to remove the dye.

? USED UP FIXER: Fixer is not used-up but becomes saturated with silver. As the thiosulfate becomes saturated, it takes longer to complete the fixing process. Film and paper will fix in a supersaturated solution, it just takes a longer time. There is nothing wrong with fixing for longer times if that makes you more comfortable with the process. Keep in mind that when all the exposed silver is removed the image is fixed, by definition.

? FIXER pH: The pH of fixer can be acid, neutral or alkaline.

If we can agree on these points, let me address the results of your test. I have successfully done the ?Clearing Test? myself several times, in the lab, in front of potential customers, and sales people. We designed this formula, originally, as a fixer/ replenisher for machine processing. Typically, film is in the fix tank for 30 seconds and some paper processes are even faster, 20-25 seconds.

As you know, Hypo should fix from 5 to 10 minutes to be complete.

Through technology, we have been able to make this Sodium Thiosulfate formula work rapidly. Kodak also does it with 641 AERIAL FIXER/REPLENISHER

Hello Mr. Zimmerman:

I?m sure that you are aware that natural laws and the laws of chemistry and physics are not the same. We found, as you state, Ammonium thiosulfate crystals to be good for fertilizer, not powder fixer. We use Sodium thiosulfate as the fixative agent. I don?t know how Ammonium Chloride got into this discussion, but we do not use it.

[rowland_mowrey]

Guys;

 

The claim by Lowell was difficult for me to believe. I know how hard it is to develop a good fixer for films that clears in 30" or less.

 

TF-4 is an excellent fixer. It will work as advertised unless the mfgrs drastically change the makeup of their products. As said above, fix time as well as development time varies with product. When I start using a new product with a fixer, I always check it out for fix time, as the halide content or ratio may have changed the fix rate. For example, new Polycontrast IV fixes slightly slower than the previous version in my tests, but the new Ilford Multigrade IV fixes at the same rate. This is based on the standard Sodium Sulfide test for retained silver halide.

 

I know it is possible to fix or just clear a film in 30" or less, but the fixer that does this is not simple. TF-4 is not simple. And, contrary to what has been said above, clear time is not equal to fix time in any way. You see, clear time reflects the approximate time to dissolve the silver halide, but not the time for it to diffuse outward. If you place the film into water at the end of the clear time, with some fix formulas, the silver halide can reprecipitate out as a haze in the film. It can even appear clear, but have retained colorless silver complexes that brown with keeping.

 

Bill Troop is right in his estimates for fix time determined by clear time.

 

Ron Mowrey

[lowell_huff1]

Hello Mr. Mowrey:

If you tell me where, I would be pleased to send you samlpes of all our fixers. Good fixer is easy to design, good developer is difficult.

[jay_de_fehr]

Hi Ron,

 

I'm glad you posted here, as I have a question regarding the aptly named, Superfix. I need to make up a new batch but am out of acetic acid to adjust the PH. Can I substitute sodium metabisulfite, and if so, at what rate? I can not praise Superfix enough; very rapid fix times, excellent capacity, no odor or emulsion swelling. I just can't see using anything else. Thanks again for the formula.

 

Jay

[rowland_mowrey]

Lowell;

 

A good fixer is hard to design from scratch - if you do the job right and know what you are doing. It is easy if you take the easy route. Although I do agree that developers are hard to formulate as well.

 

Both types of formulas require extensive testing. For fixers it includes retained silver, capacity, retained complexing agent, wash rate and image stability, for developers it includes macro and micro contrast, edge effects, speed, granularity, image tone, and capacity. This is not an exhaustive list by any means for either solution.

 

I trust Bill's results are representative of your fix, but I will post results of my own tests should I have the opportunity to try it out.

 

Jay;

 

You can use practically any acid to adjust the pH of the Super Fix formula that I posted here. The problem is that stronger acids such as sulfuric acid, even if dilute, will cause degradation of the fix (sulfurization) locally due to the strong sudden pH shift. Diluting the strong acids enough to prevent sulfurization will end up diluting the fix too much. That is why I prefer acetic acid.

 

Citric acid would be my second choice.

 

The pH range can vary quite a bit Jay. I have actually used it from 4.5 up to about 8 with acceptable results. The optimum is from 6.3 - 6.8 though.

 

Thanks for your nice comment about that fix. I know it is a winner, but I'm working on one that is substantially better!

 

Ron Mowrey

[jay_de_fehr]

Thanks, Ron. I look forward to your latest fix formula.

 

Jay

[bill_troop1]

Lowell, thank you for the 449 words.

The part you left out is:

 

How long do you think it takes TMAX 400 film

to clear in your CF fixer?

 

It would only take two more words to answer that.

 

68 degrees F of course.

[rowland_mowrey]

Lowell's answer above puzzled me for a while. Then I realized that there is a fundamental misunderstanding here excepting Bill Troop's post.

 

The Clayton rapid fix is advertized as being non-hypo, and some people speculate that it therefore uses ammonium chloride mixed with other ingredients.

 

I'm just guessing here, but some of the comments seem to be at cross purposes based on this.

 

In any event, the time to fix and the time to clear are not and rarely ever are equivalent. One relates to the reaction of the fixing agent with the silver halide, and the other relates to the rate of diffusion outward of these complexes. If the outward diffusion did not take place, then silver complexes would not build up in the fix. Logical, right?

 

Anyhow, another thing that must be tested for with strong fixers is their penchant to bleach silver images. The more acidic fixers are more likely to bleach fine silver metal, while near neutral or alkaline fixes are less likely to bleach silver.

 

This relates to very finely dispersed silver metal. This reaction is another reason why designing fixers is complex. Another is the fact that a fixer can destroy the image via collapse. Rapid removal of silver halide can produce voids in the gelatin matrix and lead to a kind of relief image similar to reticulation.

 

Don't skimp on the quality of your fix. It is as important as your developer!

 

Ron Mowrey

[bill_troop1]

I would like to clarify one fantastic piece of spin here.

 

Lowell writes,

 

"Through technology, we have been able to make this Sodium Thiosulfate formula work rapidly. Kodak also does it with 641 AERIAL FIXER/REPLENISHER"

 

Sounds like something pretty unique? "Through technology"?

 

Let's have a look at Kodak 641.

 

It's essentially a commercial version of F-9.

 

Lowell says "I don't know how Ammonium Chloride got into this discussion, but we do not use it."

 

Well, it belongs here.

 

Ammonium chloride was used as the agent for rapidity in Kodak's F-7 of 1942 (Russell, et al.). However, this agent attacks certain types of stainless steel (302 and 304, not 316). Hence, in 1947, Crabtree et al.'s F-9 formula, which uses ammonium sulfate at 6%, more or less the same amount as in Kodak 641.

 

So at first glance, this 'through technology we have been able to make' dates from 60 years ago. However, this technology had already been known long before. Precisely this indirect method was used in the Agfa Rapid Fixing Salt of 1906 (British Patent 25,869). And as a matter of fact, Haist writes, "The presence of ammonium ion in thiosulfate fixing baths as a means to secure rapid fixation was recognized as early as 1866 ..."

 

Lowell, would you care to comment on my suspicion that CF Fixer is essentially F-9/641 and that the accelerant is ammonium sulfate?

 

For the record, the speed increase of these sodium thiosulfate+ammonium accelerant fixing baths is not great, perhaps about 40%, although capacity increases of 50% were reported. You don't get the 400% over sodium hypo speed increases we expect today until you use ammonium thiosulfate or some considerably more complex technology.

 

F-9 was published with this caution: "With rapid fixing baths, do prolong the fixing time for fine-grained film or plate emulsions or for any paper prints; otherwise, the image may have a tendency to bleach, especially at temperatures higher than 68F. This caution is especially important in the case of warm tone papers."

 

Going back to an earlier question, neither sodium nor ammonium alkaline fixing baths do not bleach under any normal circumstances. There is no secret ingredient. It's a function of pH.

[ryuji_suzuki]

Is this the first time darkroom chemicals are associated with marketing hypes? I haven't tried any of the Clayton products and I stopped buying darkroom chemicals many years ago, but if what Bill said was really from the manufacturer/vendor, any reasonable photographic chemists would know that's very skeptical. I frequently review photographic chemistry literature and also keep up with latest issues of scientific journals and newly granted patents, but to my knowledge, there's no new technology that gives that kind of performance (of course, trade secret is a possibility, but in the hands of any competent analytical chemist, such an approach will find miserable failure very quickly).

 

Clearing film in xyz seconds? Big deal. If I use a film based on chlorobromide or bromide emulsion containing quaternary ammonium salts and polyethylene oxides as accelerating additives (very common additives to find in emulsions after 1960s), the clearing time can be as short as 5 seconds even in a dilute hypo solution at room temperature. Many slow "negative" type emulsions used for motion picture and duplicating films are pure bromide type that fixes rather rapidly. Many old fashioned document films, graphic art films, etc. are chlorobromide emulsions, which fix even faster. (Exact halide composition depends on the available technology and these should be taken as a very rough classification.) The problem is that many of those lousy fix solutions that can fix AgClBr in dozen seconds need many minutes to fix AgBrI emulsions, particularly when the fixing solution is partially exhausted. (Likewise, even TF-4 would require 1-3 minutes to clear when the solution gets partially exhausted.)

 

So what do I think of Clayton fixer? I don't know. I haven't used it, and I probably won't.

[bill_troop1]

>(Likewise, even TF-4 would require 1-3 minutes to clear when the solution gets partially exhausted.)

 

That's an important point, and why I emphasize testing clearing time throughout the use of a batch of fixer. Needless to say, when speaking of clearing time tests here, we are presumably referring to best possible results with fresh fixer.

[User_502260]

I have seen many disagreements in this forum over the last few years but this one seems more unnecessary than most. Let me first say that I enjoyed reading both the Film Developing Cookbook and the Darkroon Cookbook and I refer to them from time to time. The exact number of seconds it may take for a particular fixer to clear or fully fix a particular film is something we can test fairly easily. Whether it is 30 seconds or 45 seconds or even several minutes is not terribly important. We can all test the available chemistry or make our own and use it as we find appropriate. The exact composition of Agfa fixer from 1906 is not really in question and has little bearing on how most photographers would proceed today.

 

I have contacted Lowell Huff many times over the last few years and he has always been helpful. The Clayton products I have used include F60 film developer, P90 paper developer, Odorless Fixer, Odorless Stop Bath and CP Film Developer. All of these products have given excellent results. Both Mr. Troop and Mr. Huff have much practical experience in film processing and the chemistry for it and we are lucky that they choose to contribute to this forum. The same goes for Mr. Mowery, Patrick Gainer and others.