Straight undiluted fixer

[Bill, 70's military B&W]

Anyone use their fixer straight out of the bottle for film and paper? Then just pour it back in and occasionally check to see if it's exhausted.
The advantage is convince, what would the disadvantages be? Would you have to adjust your time in the fixer?
Bill

[Pawlowski6132]

Huh?

[Dan Henderson]

Well, TF4 fixer is supposed to be diluted 1:3 for use. So using it straight out of the bottle it is going to be really strong. Maybe too strong for film and fixer? Maybe strong enough to bleach the image in the same way that fixing film or paper for too long can do? Maybe making it very difficult or impossible to wash out of film and especially paper? I don't know. I am not a chemist so I tend to follow the directions on the label.

[wallrat]

I would say that there is practically no convenience there and a lot of danger. If for some reason you see some major convenience, I would test it on a number of negatives and prints that you do not care about first. Please don't take my tone as snide or snippy, it's completely out of concern. I would never do it.

[Vaughn]

Kodak Rapid Fixer, diluted for film -- mixed in a gallon jug (32 oz of part A, add water to make almost one gallon, add 3 oz of Part B and water to make a gallon). Student use it for roll film, returning it to the jug until it flunks the HypoChek test.

Basic rule, if it is purple, fix it longer (a lot of TMax is used).

[Doremus Scudder]

Undiluted fixers of the rapid type, i.e., ammonium thiosulfate based fixers will not fix correctly at high concentrations. If you use them straight, you will underfix your film or paper. The proper chemical reactions do not take place in concentrated fixer.

Rapid fixers must be properly diluted to work correctly. Follow the manufacturers' instructions. They have the labs, chemists and have access to al the research (especially if you are using a Kodak or Ilford product). Trust them.

If you are worried about convenience, then mix smaller quantities and use them to exhaustion. Use a clip test from a known film to test film fixer; when the clearing time is twice that in fresh fixer, discard the fix. Use capacity guidelines for paper and two-bath fixing for fiber-base paper (I use two-bath fixing for film).

You can also use fixer one-shot in weaker dilutions. I use Ilford Rapid Fix in the 1+9 dilution or even weaker when developing small amounts of film (a couple of sheets, say). If you do this, determine your fixing time in advance with a clip test. Double (or triple for T-Max and Delta films) the clearing time.

Fixing directly affects the permanence of your negatives and prints. It is not the place to cut corners. There is a ton of information here and elsewhere about fixing effectively and correctly with less conventional methods. If you don't want to dig through that, then stick with the manufacturers' recommendations.

Best,

Doremus

[Bill, 70's military B&W]

It was something I heard about, I was just wondering if any one else would have an opinion on it, and several have.
I think I like the idea of mixing up a gallon and pouring it back into the bottle until it fails the fix-test. Then it's time for a new gallon.
Thanks,
Bill

[wallrat]

Bill, I think that is a good decision. Buy a bottle of hypo check and put a couple of drops in before each dev or printing session. If a white precipitate forms from the drops, the fix is done. You can also do the clearing test, I just like the hypo check as it's faster. I always fix for 4 minutes (Tmax for 6 - 7) regardless of the fixer and I have always had great results. I currently use TF4 from Photographers Formulary for PMK, Illford Rapid for general fixing. I just bought some Eco Pro from Freestyle to replace TF-4. It's supposed to be the same stuff but it was far more economical. For a 1 gallon jug (makes 5 to 8 gallons) it was $20. Good Luck!

[chassis]

I have used Kodak Fixer in this way for 30 years, if I understand the OP. I mix the powder per instructions on the bag, creating one gallon of solution. I use this undiluted for film and paper. After the film processing or printing session, I pour the solution back into the gallon bottle. It is a subjective decision based on film color vs. time, when I toss it. I have looked at my 30 year old prints every now and then and I don’t see any undesired effects.

[Doremus Scudder]

I have used Kodak Fixer in this way for 30 years, if I understand the OP. I mix the powder per instructions on the bag, creating one gallon of solution. I use this undiluted for film and paper. After the film processing or printing session, I pour the solution back into the gallon bottle. It is a subjective decision based on film color vs. time, when I toss it. I have looked at my 30 year old prints every now and then and I don’t see any undesired effects.

Let's make sure we make the distinction between "rapid fixers" and "conventional fixers." The former are ammonium thiosulfate based and fix faster than conventional fixers, hence the name. Ammonium thiosulfate likes to be in solution more than dry, so these kind of fixers are generally sold as liquid concentrates, typically 60% ammonium thiosulfate plus the other chemicals in the recipe. These fixers must be diluted to working strength in order to fix correctly. Used at full strength, they will NOT fix properly, since the necessary reactions are inhibited by the strength of the solution. Fixers included in this category are: Ilford Hypam and Rapid Fix, Kodak Rapid Fixer, and the newer generation of alkaline fixers such as TF-4, etc.

"Conventional fixers" have been used much longer (since the 19th century) and are based on sodium thiosulfate. These fixers are almost always sold as packaged powders (e.g., Kodak Fixer as opposed to Kodak Rapid Fixer). These fixers are mixed directly to working strength and, therefore, need no further diltuion.

Using a gallon of Kodak Fixer (mixed the the correct dilution from powder) until exhaustion is just fine (as long as the solution doesn't go bad due to age in the meantime). However, using Ilford Rapid Fix or TF-4 straight from the bottle without first diluting it to working strength will result in underfixed film or paper. I was under the impression that this latter is what the OP had in mind. If it was only reusing a correctly mixed gallon of powdered fixer, then I misunderstood. However, in light of the word "undiluted" in the thread title, I think this is not the case.

Keep in mind that whatever fixer you reuse, the fixing time increases as the fixer is used. The only reliable way to determine correct fixing time for film with partially exhausted fixer is to do a clip test. Fix for a minimum of twice the clearing time, or three times for Delta and T-Max films. I always add a 10% fudge factor when using fixer this way to account for the exhaustion during the fixing itself. With film, it is better to err on the side of longer.

For papers, use throughput as a guide and follow manufacturers' capacity recommendations unless you have an accurate way to measure dissolved silver in the fixer itself. For fiber-base paper, two-bath fixing is indispensable for both permanence and economy.

Best,

Doremus

[Bill, 70's military B&W]

Doremus, I bought a chemical to check the fixer, to see if it's exhausted. If I dilute a working solution according to Ilford's instructions, and pour it back into the working solution bottle, test it each time, then I can use the time as recom by Ilford. I am shooting sheet film and do not have a leader to clip from. I was under the impression that the chemical test was enough to tell me that the fixer is within limits and will do the job.

What would happen if after I've used the working solution for a while, and I know that it is becoming exhausted but it passes the chemical test, that I just increase the time for film/paper by 25%.

I've had some recom that I use Ilford Rapid Fixer at 1:9 for both film and paper. A friend says he's been doing it for years with no problems. Only has 1 container of fixer and uses it up faster, so that he has to make a new working solution more often, keeps it fresh. He tests before each session.

The 2 bath fixer, I have not been doing that, but I will. Is it for film and paper? 50% of the time in each of the 2 baths, when #1 fails the test then #2 becomes #1...and so on.

I'm just getting into the darkroom, so I hear a lot of stuff, see a lot of ways of doing it... but I'd like to get some opinions before I incorporate it into my work flow. So if some of my questions sound fundamentally flawed, well it was something I heard. And by asking the question, the advice I get will stop me from doing it. So I appreciate all the advice. I have no problem asking a stupid question, what I have a problem with is doing something stupid because I didn't ask!

[Bill Burk]

Two fixer trays are used for paper. The first bath is the "older" bath which may have some carryover developer, stop bath contamination. The second one is the freshest fixer which you should always maintain at the best quality. Then make more fresh fixer and demote your older second bath to the first bath.

Thanks for clarifying Doremus, I *never had any problem re-using the gallon of powdered Kodak Fixer, no problem with longevity or capacity (*of course I had problems over the years, but they were infrequent and each has some reasonable explanation). But with the rapid fixer, I don't get anywhere near the shelf life or capacity once mixed, when used intermittently (as is my practice). So lately I have been mixing my rapid fixer fresh for film, and my second bath for paper.

[Doremus Scudder]

Bill and Bill, :-)

I distrust the "Hypocheck" type of chemicals for determining fixer exhaustion. Although the test might tell you when it is time to discard your fixer on the basis of dissolved silver (whose standards...?), it won't tell you the fixing time you need, nor will it tell you if the fixer has gone bad from age (having the sulfur precipitate out of solution). Bite the bullet and sacrifice a sheet of film for doing clip tests. I cut a quarter-inch strip from a 4x5 sheet, then cut that in half and use that; one sheet lasts a long time (20+ tests) and probably cheaper than the chemical you bought :-)

Don't use the same fixer for film and paper. There are different by-products from film fixing that are not good for paper and the time to exhaustion varies widely. Plus you can get particles from the paper fixing in the solution which then stick to your negatives and ruin them.

Two-bath fixing is primarily for fiber-base papers. For film and RC papers it is not strictly necessary. I, however, use two-bath fixing when doing large batches of negatives because I have fewer concerns about adequate fixing and it is more economical after a certain volume.

Basic two-bath fixing: mix two fixing baths. Fix for half (and a little more) of the recommended fixing time in each bath. When the capacity of bath one has been reached (clip test or capacity guidelines), discard it and replace it with bath 2. Mix a fresh bath 2. Continue this through no more than 7 cycles.

The majority of the fixing is done in the first bath and the relatively fresh and by-product-free second bath ensures adequate final fixing.

I use my rapid fix one-shot (or rather "one batch") and mix enough fix for the number of sheets I have to develop. I, too, find that rapid fix does not last that long once used and stored. For small amounts, I use 1+9 dilution and a minimum of 300ml of solution in a 5x7 tray. For larger batches, two-bath fixing at 1+4. The exact scheme depends on the number (and type) of films to be fixed.

Generally, fixing is not the place to cut corners; it directly influences the longevity of your negatives and prints. Unfortunately, it is more complicated to understand fixing, how it works, and when fixers are exhausted than understanding the other photochemicals. It is worth learning a bit about it. Searching here and at APUG is likely the best way to get reliable info.

Best,

Doremus

[cyrus]

You don't have to cut up a 4x5 sheet -- I keep the bits of leader from my 35mm films to use as a film clearing check.
Like Doremus Scudder said, you really shouldn't wait until it fails the fix test for fixing fiber paper. By then, there has already been a build-up of non-water soluble by products that will get into the paper and won't come out. Of course people debate endlessly over whether they present a danger, but as I've read here and there, if you're really into archival, stopping short of the fix test failure is best. I guess there isn't a problem with reusing fixer until fixer fail on film though because you can always observe the effect of fixer clearing the film and confirm how long it takes to happen.

[Bill, 70's military B&W]

Bill, Doremus and Cyrus,
Thanks for the advice, I really appreciate it. Sounds like 'there is more' to this fixing than I realized. I have some collapsible bottles coming soon so I should be able to mix and store my chemicals efficiently. I'll treat the fixer with more respect, and I'll learn the 'film clip test'. Right now at the beginning I'm just using RC paper, but once I feel like I know what I'm doing I'll break out the FB paper and an extra tray for 2nd fixer.
Thanks, Bill

[cyrus]

Well Bill, bad news about those collapsible bottles... :)

Fixer doesn't need to go into collapsible bottles, really. Air won't do much to it so there's no point to squeezing out the air in a bottle. I know people who keep trays of working solution fixer in their darkroom sink for months and months, covered only with a piece of acryclic, and there is no problem (it will take a much longer time for the sulfur to precipitate out.)

Developer is what oxidizes. But those collapsible bottles will eventually start to leak as the accordion folds flex and the plastic weakens. The plastic material also allows air to seep in. I personally prefer gallon-sized amber glass bottles to store Dektol and D-76. Some people also throw glass marbles inside the bottles to further eliminate the air in the bottle once it becomes part empty, but I have never bothered since I tend to use up the chemicals quickly and don't let them sit on a shelf too long enough oxidize, or I mix up fresh batches of developer if I haven't used it in a while. The stop and the fixer solutions have long shelf lives so no worries there -- you can store them in regular plastic bottles (still, filtering the reusable solutions once in a while is a good idea.)

As a general matter, screwing around with chemicals is false economy. The best approach is to dump it and use fresh stuff whenever possible.

The film test for fixer: take a piece of a b&w film, like the bits snipped off of a role of 35mm, and swish it in your working solution of fixer. Time how long it takes for the dull gray emulsion to be dissolved away. Usually, it should be less than 2 mins for a new solution at 68 degrees. Once it reaches more than 4-5 mins, it is time to use fresh fixer.

PS: once you use fiber papers, make sure to use hypoclear too!

[Bill, 70's military B&W]

Cyrus, Thanks,
Here is a some more basic questions, do you perform the film test for fixer with the lights on so you can see when it dissolves?

I'm using Permawash with my RC paper now because I'm trying to make friends with selenium toner.
Toner seems to increase the contrast quite a bit, which is a good thing but you have to plan ahead for it. Good to rescue a print that needs more contrast.
How long does selenium toner last in a working solution? Do you use it until you notice it becoming ineffective? How many minutes is considered excessive?

I guess the collapsible bottles will be used until I notice a problem with them. I'm going to keep my eyes open for amber bottles. Wine bottles are plentiful, but what do people use for a stopper, cork comes to mind but is it a good material with the chemicals?

I'm using a wetting solution for my film, does it work on prints too?

Bill

[cyrus]

Hi Bill
Sorry for the late reply.

Yes, the lights are on, so you can watch the fixer clear the film snippet. You can see it work just fine under a safelight.

I use my selenium until it doesn't cause a color change anymore. I don't think I've ever used it for more than 15 min at a time, and if I need something more is use a warmer grade of paper.

Yes wetting solution works for both papers and film. Wetting solution is just a surfactant, like that found in common dishsoap (in fact you can make your own wetting agent at home by using a TINY TINY bit of dishwashing detergent in a container of distilled water -- if it bubbles, you used too much.) It makes water not stick to things and instead stick to itself, and so it runs off quicker. The purpose of wetting solution use is to ensure that there are no spots left on your negs by water drops as they dry off. I generally don't bother with it since I do a final rinse with true distilled water, which leaves no marks as it dries.

Wetting solution of course should not be confused with hypoclear which an entirely different chemical -- its function is to "neutralizes" the residual fixer in prints or negs and make it easier to be washed out (and this is particularly important for a thorough washing of fiber paper.)

[Ian Gordon Bilson]

I'll add my 2cents to this discussion. 2-bath fixing is "state of the art" for film and prints. But don't use the same mixes for both.
Check for clearing times by putting a dot of fixer on your film chip,and wait for it to clear. Then immerse the chip and time the period during which your dot disappears.
When this time doubles,dump the first bath.
As for marbles to fill the container? Have you any idea how heavy and unwieldy a 2 liter glass bottle full of marbles is?
Use Butane,and save your wrists.

[Leigh]

As with all other chemistry, I follow the manufacturer's instructions.

I have neither the equipment, expertise, nor inclination to conduct the experiments
required to justify deviation from those recommendations.

I respectfully submit that the same is true of the OP.

- Leigh

[Bill, 70's military B&W]

I have several sheets of 4x5 that are garbage, exposed but never developed, just sitting uncovered in a drawer. I use them for practice loading film holders and developing drums. I cut one up and put it in the fixer and one side of it cleared in about 90 seconds. I did it with the room lights on, is that a problem? I just reread where cyrus said to do it under a safelight.

Give me one small way of making a wrong turn, and I'll do it every time! My portfolio proves it!!!

Bill

[Doremus Scudder]

I have several sheets of 4x5 that are garbage, exposed but never developed, just sitting uncovered in a drawer. I use them for practice loading film holders and developing drums. I cut one up and put it in the fixer and one side of it cleared in about 90 seconds. I did it with the room lights on, is that a problem? I just reread where cyrus said to do it under a safelight.

Give me one small way of making a wrong turn, and I'll do it every time! My portfolio proves it!!!

Bill

Bill,
There is a ton of information here on how to do the clip-test correctly...

At any rate, here is the "best practice" method.

First, everything can be done under normal room lighting; no need for a safelight (which would fog film anyway... and be hard to see the clearing under...)

Take a small piece of the film you wish to clip test. Note: you must test the same film you are planning on fixing or the test is not accurate. Place a drop of the fixer in the center of the film clip.

Wait 30 seconds or so for the film to begin to clear where the drop is.

Then immerse the clip in the fixer and agitate. Start timing when the film hits the fixer. (I leave a bit to hold on to that stays dry, since I cut a 4-inch strip from a sheet to use as a clip; just make sure the part with the drop on it is completely immersed). You will see a clear dot where the drop was.

Note the time it takes for the rest of the film to clear so that the dot is indistinguishable from the rest of the film (i.e., everything is completely clear). This time is your clearing time. Do this with fresh fix and all the films you use and keep the times in your records for easy reference.

Use a clip test before each batch to determine 1) if the fixer is exhausted or not, and if not, 2) the fixing time for the next batch.

1) The fixer is exhausted if the clearing time is double the clearing time in fresh fixer (which you have noted and have in your records for easy reference, of course). Discard and mix a new batch (and do another clip test).

2) Double the clearing time to arrive at the minimum fixing time for conventional films; triple it for hi-tech films like Delta and T-Max. I also add 10% to compensate for fixer exhaustion and never fix for a shorter time than the manufacturers' minimum time, even if 2x the clearing time + 10% is shorter.

Keep in mind that film is on an impermeable base; it does no harm to fix longer than necessary as long as you don't leave the film in for half an hour or longer. For films that have that annoying pink or blue dye in them that doesn't clear easily, longer fixing is recommended. Err on the side of fixing too long.

If you're doing lots of film (30 sheets or more at a time), then two-bath fixing is more economical. I mix two 500ml fixing baths and run the film through in batches of 6-8 sheets. I clip test the first bath before each batch to get the clearing time. I like overkill, so I fix for 2x the clearing time in each bath. When the clearing time in the first bath reaches double that in fresh fixer, discard that bath, replace it with the second bath and mix a new second bath. Continue this through a maximum of 7 changes (I've never got that far... when I develop a hundred sheets or so in a couple of days I usually get through about 2-3 cycles).

Good luck,

Doremus

[Ian Gordon Bilson]

Ground Hog Day,surely?

[Doremus Scudder]

Ground Hog Day,surely?

Don't call me Shirley! :)