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Alkali Fixers - The Myths & Legends

Photo Engineer said:
If I said that it relied on swelling agents, Isoelectric point and the relative solubilities of the ingredients related to cations what would be your response?

PE
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If that was all you said, I probably wouldn't respond at all.
But I would be happy that we were at least facing the same direction.
 
Why is "no" such a hard concept? Is it the "n"? Is it the "o"? Is it the two letters together? Perhaps it is the order of the letters.

A reason is given. It is ignored or not enough. Accept the reason whether or not you like it. For reasons that can't be stated or that you cannot understand you cannot let it go. How is this working for you?

PE freely shares a lot of information with us. If he can't or won't share some of it => get over it. Are you just trying to drive him away from APUG??? Would that make you feel better?

Steve
 
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Ray Rogers said:
Frankly, I have been up all night working on a new emulsion formula series.
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Ray - Let's take that thought over to the Emulsion Making forum and talk about that. I've been working on one emulsion formula for the last year and a half, so I'm interesting in hearing about your series of formulae. WHat are your goals, and what have you done to try and achieve them?

I've made 3 iterations in my emulsion goal (to make a t-grain emulsion is my goal), and mostly at this point, all 3 iterations made major improvements in the actual physical techniques/equipment used, and probably much less improvement in the actual emulsion. Still not a lot of t-grains in the emulsion, but I have great hopes for the next iteration!

Anyway, let's talk about this for a bit!

Kirk
 
Plot of fix/swell/wash rate vs pH - Bone Gelatin

I have posted this graph before on APUG and Photo Net illustrating the effects of pH on the fix rate, wash rate and swell of bone gelatin in photomaterials.

This comes from a site in Australia and was passed on to me several years ago by someone. The site is concerned with archival properties of primarily motion picture film and has studied fixers wash rates as a function of pH.

Thus, this is a graph that encompasses all 3 characteristics of any photo product using bone gelatin, on a relative scale based on thickness and hardening. Rate/swell goes up reading left to right.

If you wish to use Porcine gelatin, then flip the chart on the X axis and it will roughly reflect the differences in the two gelatins. In the case of the pig gelatin, the minimum, instead of being at about 4 pH units would be at about 9 pH units.

PE
 

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Photo Engineer said:
I have posted this graph before on APUG and Photo Net
illustrating the effects of pH on the fix rate, wash rate and
swell of bone gelatin in photo materials. PE
Click to expand...

The graph only deals with the swell of the gelatin and that with
regard to it's gain in weight. The graph deviates considerably
from one included by Dr. Robert Chapman in an article for
Photo Techniques. Both do agree though on the ph of the
isoelectric point, give or take some little.

His article dealt with older emulsions and today's hardened
emulsions. Dr. Chapman holds a doctors degree in chemistry
and has worked for DuPont's and Unicolor's product research
departments.

I've the article to locate. Will make an effort to post. Dan
 
Dan;

The graph is good enough considering the huge variation in Bovine gelatin around the world, the huge variation in the type and quantity of hardener used and gelatin coated and etc. This figure represents a good enough approximation for our purposes.

I have run tests regarding weight and swell both, and have done them with and without hardeners at EK and I could draw a generic family of graphs that fit the one posted above. I have run hardness tests vs pH as well, and wash vs pH etc. etc.

The bottom line is that one can track wash rate, fix rate and swell by means of the above graph and it fits well with experimental results.

PE
 
Looking up something else I spotted that Kodak Research showed that increasing the level of other salts, and the buffering can also reduce the swell of the gelatin during fixing. The Research was done by A.Green & G.I.P.Levenson & published in 1968, I've not seen the research paper.

This could indicate that TF-3 might actually be better than TF-4 with it's higher level of buffering.

Ian.
 
Ian;

Specific salts cause swelling and others decrease it. For example, Sodium Sulfate decreases swell, but Sodium Sulfite has little effect. Potassium Sulfate decreases swell but also can virtually stop fixing. Potassium ion in fixers can poison them. This is found in several texts on the subject.

Mees and James show that fixation is a function of a "U" shaped curve with rate the Y axis and concentration the X axis. There is an optimum point for fix rate and at either end, you can slow it down.

So, saying TF4 or TF3 (or TF5? ) differ or one is better than the other would have to be shown experimentally. The borax buffer in TF4 adds stability. That I have proven to myself, but I never compared them for activity.

PE
 
I got interested in non-acid fix a long time ago when I finally admitted to myself I couldn't take the smell of acetic acid any more. Darkroom odours in general were just no longer acceptable; the two biggest candidates for elimination were sulfur dioxide and hydrogen sulfide. Either one could stop me in my tracks with just one whiff.

(As an aside, I've only become worse as I've aged. The fabric they use for tee-shirt labels now sets my skin on fire, so I have to snip them out. Same for the label in underwear shorts. There's a product called Dawn for washing dishes; if it's in the room my eyes and face feel weird and I have to leave. For washing clothing there is Gain, whose smell gases me out ... fussy photog, eh?)

Anyway, to create sulfur dioxide all that's needed is sodium sulfite (maybe from the developer) and a little acid such as found in stop bath. A little dribble action in the sink while prints get moved and there it is. Hydrogen sulfide is less common but equally unacceptable. Please, no potassium polysulfide in closed spaces. Do it in the garden. Beans in confined spaces for lunch, anyone??

Basically, if you'll pardon the pun, to eliminate common odours from a regular darkroom, eliminate acid. I use plain tap water for stop bath (I use four changes of water in the tray; takes only moments.) I never use fix that has acid as a component. (Interestingly, Kodak Fix F6 truly is odourless even though it is acidic. Kodak F5, however, is eye-stingingly of academic interest only, and can be said to have been superseded by the superior new technology of F6.)

Working with a fix that contains no acid means no untoward gases will come out of it, and also that it will be very easy to use selenium toner after the fix.

I don't care if my fix is alkaline as long as it is not acidic. The fix I use is not particularly alkaline; it's probably close to neutral. It comes from the appendix to The Print by Adams; he called it plain fix. It's not quite plain: it consists of sodium thiosulfate and sodium sulfite. I never use hardener - hardener requires acid. Commonly available black and white films today don't really need hardener. Instead of sequestering agents and the like, I just make up my fix with distilled water. No tap-water roulette. Lake Ontario was long ago declared to contain dioxins. Too bad I have to bathe in it.

Adams' plain fix is cheap. I buy hundred pound bags of sodium thiosulfate and similar packs of sulfite. It's incredibly easy to mix up. There is no need to prepare liquid concentrates or do anything but keep the dry components dry until they're needed and then dissolve them in water. (I treat developers the same way. Just keep dry powders and mix up to working solution when needed. Nothing ever goes bad any more.)

I realize the discussion is at least partly about scientific investigation. My purposes are about practical operation of my own little darkroom space. Cheap, easy and odourless are requisites. Maybe odourless should go first.

I'm only talking about a 'regular' black and white darkroom. I know nothing of color darkrooms, and specialized processes like PMK have their own needs. For ordinary processing of Kodak, Ilford, etc., currently available black and white films and papers, special darkroom substances are not necessary. Such as acetic or citric or any acid.

Speaking of 'myths', there is the myth of high capacity. In a fix used by low volume workers like me, in a plain vanilla black and white darkroom, a high capacity fix is a liability. A low capacity fix is a legitimate tool. The high capacity fix just gets to sit around longer, gathering fixing by-products, aging, waiting to be 'used up'. The low capacity fix fixes a given amount of photosensitive material and is discarded. No time to decay. Over the eons I've found that if I am ready to do a serious darkroom session, I can make up my usual three liters of fix and it's fine for the amount of work I can do in a day or two. It almost always has enough life left to do a session of trials and tests and poking around preparatory to another 'serious' session, when I will mix another fresh batch. This is not an expensive way of working, since plain fix is so cheap, nor does it take up time, since it mixes up in a swish. Throwing it down the drain is not doing serious harm to the environment - it's only thiosulfate and sulfite. The problem effluent is silver compounds. The longer a fix sits around and the more paper (silver) that runs through it, the worse the silver complexes. Another reason for a low capacity fix.

There are good reasons for using non-acid fix in the darkroom, quite apart from considerations of fixing speed, capacity, etc. Elimination of darkroom 'fumes' (hateful word) is the number one reason for me. I'd pay a lot for a sweet atmosphere where I work, but it turns out it is cheaper.

There is also the improvement in the performance of selenium toner when no acid is present in the production environment. But that is another story.

(I've pontificated on my website about this and other subjects. Under the 'technical' button on the table of contents page.)

regards,
--le
________________________________
Lloyd Erlick Portraits, Toronto.
website: www.heylloyd.com
telephone: 416-686-0326
email: portrait@heylloyd.com
________________________________
 
Lloyd, there are so called odourless fixers that are commercially available that are acidic, but they use citric acid instead of acetic acid. Fotospeed FX-30 is a fixer of this type.
There is also Tetenal Super-Fix Odourless which is claimed to be pH neutral. Either of these fixers should make the darkroom a much more pleasant place and they provide good value for money if the larger sizes are bought.
 
Keith Tapscott. said:
Lloyd, there are so called odourless fixers that are commercially
available that are acidic, ...
There is also Tetenal Super-Fix Odourless which is claimed to
be pH neutral.
Click to expand...

There are those who take to odorless acidified fixes. A little
acid or neutral they are not alkaline. My guesstimate, Lloyd's
fix runs about ph 8 or very close to TF-3 and 4. Perhaps
Lloyd will supply us with his fix recipe. We both favor
VERY long lasting dry components and we both
disfavor odorous brews. Dan
 
Above pH 7, you have to contend with the odor of ammonia which increases with alkalinity. So, if you use ammonium thiosulfate, and the pH is alkaline, then you have to contend with an odor.

If you use Sodium Thiosulfate you have to have the patience and lifespan of Methuselah because Sodium Hypo fixers are so much slower than Ammonium based fixers.

PE
 
In regard to DR odors I agree with the Lloyd's post. I switched to TF-4 and a water stop which solved my slight respiratory irritation. However, I exercise an abundance of caution and use a weak acid rinse for 8x10 or larger prints in a vented community DR vs my unvented DR at home.
 
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>However, (I may be wrong!) but I think the most valuable lesson we will ever be able to learn from you is how to think like a Kodak researcher.

Surely the best way to do that is to go and find out things? Just do it!

>Strange, but I feel that Kodak research was somehow better than the Kodak products that evolved from it.

That is true to the extent that thousands of fabulous products were developed and never sold. One example is Grant Haist's developer/fix-incorporated papers. In one invention, you process the paper for 30 seconds in sodium carbonate, wash for a minute, and the entire develop/fix/wash sequence is out of the way with no environmental hazard.

In a related invention, the paper is simply heated, to achieve develop, fixation, and archival stability.

These are expired patents. You can find them. What is more, you can make them. Grant made them in his garage, with off the shelf wallpaper equipment.

So? Go out and find them. If, that is, you're interested in something that was cutting edge 30 or 40 years ago. It's certainly a lot more cutting edge than anything being discussed here. We're talking about minute refinements of a completely conventional process here that is about 150 years old. Why not simply get rid of the chemistry as best we can, which means putting it into the paper, and leaving it there?
 
Bill;

As you know, but these people probably don't, I worked with Grant on a color version of the heat processed paper. Yes, it works and very well. I have hand coated and machine coated Grant's B&W paper using the isothiouronium blocked fixing agent, and phenidone for a developer. It takes about 10" of heat to completely develop and fix the paper and the results are surprisingly good.

BTW, this grew out of the Kodak Ektaline 2000 Oscillographic papers which used a single solution stabilzer and a heat drum. The chemistry was in a single "monobath" that was activated by heat.

There are literally thousands of potential new products that never saw the light of day.

PE
 
billtroop said:
Grant made them in his garage, with off the shelf wallpaper equipment.
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I've got no wallpaper in my garage Troopy in fact all that's in there is my very low mileage Austin 1300GT.

But am churning my way through very interesting research & Patents particularly from Fuji on fixers Interesting that they think stop-bath type is very helpful.

But perhaps Fuji's research was more advanced

Ian.
 
Ian;

Fuji continues to work on thermally processed B&W products. I have that directly from Tadeki Tani himself.

After thinking about this, I'm adding a bit more.....

If Fuji research was so good, how come the thermally processed materials were first invented elsewhere, how come DIR couplers and color stabilizers were invented elsewhere. At one time, Kodak R&D was over 20 years ahead of Fuji. It took them a concerted effort to catch up and many man years of work.

We had reports that some of their engineers in R&D were working for 24 hours on their projects with cots in their offices, and their wives bringing them fresh clothing along with packets of food. This was all in the name of catchup. It was not anything superior, it was intensity and concentration.

PE
 
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Ian Grant said:
There's something about the Japanese, they have something missing in the West, but they are canny. (Like the Scots).

Ian
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That Kodak, overall, had the best research is freely and honestly admitted
by even top Fuji scientists.

I think this reflects infrastructure and capital more so than brain power however...

Kodak has always been strong on research and even spent large sums to assimilate technology they did not develop themselves... (Kodak = Borg?)

More than 15 years ago one of Fuji's senior researchers told me they were about 6 months behind Kodak, as evidenced by patent trends.
I did not and still do not have the ability to evalualate that claim, but I respect his insight.

I am sure the Japanese researchers worked very hard,
as did the Americans did when the Germans were on top.

The real question is what happens once your are on top?
Do you continue at full speed, thus maintaining that lead,
or do you relax and begin to gloat?

I think it is wrong to compare research in this way, based on nationality.

That said, one thing I think I have noticed is that the American researchers are more arrogant about their own abilities than the Japanese researchers.
 
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That reminds me that there was a color paper on the market about 30 years ago for making prints from slides, I think it was Agfa. The processing was just plain water, must have been some kind of Polaroid process. I have some of the prints, and the colors still are pretty good.

 
Ray;

Basing R&D on nationality is really reasonable when one factors in national policies that reflect support of companies and R&D in general. This is epitomized in the phrase "Japan INC" used for quite a while in application to advances in Japan in recent years.

In fact, photography was placed at a cabinet minister level in Japan, in order that they might surpass the US. In the US all advances were made by the industries concerned, in this case Kodak.

PE
 
Photo Engineer said:
Basing R&D on nationality is really reasonable when one factors in national policies that reflect support of companies and R&D in general.
PE
Click to expand...

This is exactly the reason why Ilford lost out, they came under the control of the Air Ministery during WWII and were forced to drop much of their research, particularly into colour emulsions, but also Phenidone.

A measure of just how much that set them back is it was only in the early 50's that Phenidone came into use, despite the research being done in the late 30's.

Ian
 

I don't remember the name of it, but I used to use htis product. All the prints I made with it in the 80s have turned yellow a bit...

Anyway, it was not plain water used to process it. It was about 10% sodium hydroxide! That's quite a big difference from plain water.
 
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