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
Huh?
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.
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.
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).
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
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
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!
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.Originally Posted by chassis
"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
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