squirrel$$$bandit
Veteran
OK, I've been developing film for a couple of years now, and...I just happened to notice on the Rapid Fixer bottle a little table of shelf life times. Unopened concentrate, 2 years; opened but capped concentrate, 6 months, 1:4 solution, 7 days.
7 days?!!? Uh...I have been using this same bottle of concentrate for two years, mixing up a new 500ml batch every six months or so. And using the diluted fixer (stored in a dark glass bottle and filled to the top) for all of those 6 months...maybe 25 times total before mixing up a new one (and new stop bath along with it.)
So...are all my negs from these past two years doomed? I went through all of them and none looks as if it has degraded at all. (I scan, hi-res, the day I develop and rarely return to the negs, so this wouldn't be quite the tragedy it might seem.) I guess it's time for a new bottle of fixer, though it's a shame--I haven't used even close to all of it. I shoot maybe 50 rolls of B&W a year...probably more in the near future, as I have kinda given up color film for digital. So how should I be using fixer? Should I be seriously mixing up a new batch every week?
Veterans, advise.
7 days?!!? Uh...I have been using this same bottle of concentrate for two years, mixing up a new 500ml batch every six months or so. And using the diluted fixer (stored in a dark glass bottle and filled to the top) for all of those 6 months...maybe 25 times total before mixing up a new one (and new stop bath along with it.)
So...are all my negs from these past two years doomed? I went through all of them and none looks as if it has degraded at all. (I scan, hi-res, the day I develop and rarely return to the negs, so this wouldn't be quite the tragedy it might seem.) I guess it's time for a new bottle of fixer, though it's a shame--I haven't used even close to all of it. I shoot maybe 50 rolls of B&W a year...probably more in the near future, as I have kinda given up color film for digital. So how should I be using fixer? Should I be seriously mixing up a new batch every week?
Veterans, advise.
Juan Valdenebro
Truth is beauty
Wow!
I use the working solution just for two roll films (6 minutes, 10 minutes) and only if I fix both of them during the same or next day!
6 months and 25 rolls seems like a chemical miracle!
Maybe they've been just cheating us!
Cheers,
Juan
I use the working solution just for two roll films (6 minutes, 10 minutes) and only if I fix both of them during the same or next day!
6 months and 25 rolls seems like a chemical miracle!
Maybe they've been just cheating us!
Cheers,
Juan
squirrel$$$bandit
Veteran
Well, it's only a miracle if my negs remain intact. They probably won't.
I am going to have to seriously change my workflow...
I am going to have to seriously change my workflow...
palec
Well-known
Ilford writes that 1l of work solution will cover 24 rolls.
Until recently I used 500ml of work solution for 10-14 rolls per month, then mix a new one. Maximum was 2 months.
Month ago I switched to two bath fixing 2 minutes in first (old) fix + 2 minutes in second (new) fix to get rid of purple flood on new film emulsions (like Delta 100).
My opinion is that 7 days is lifespan of fixer in open trays.
Until recently I used 500ml of work solution for 10-14 rolls per month, then mix a new one. Maximum was 2 months.
Month ago I switched to two bath fixing 2 minutes in first (old) fix + 2 minutes in second (new) fix to get rid of purple flood on new film emulsions (like Delta 100).
My opinion is that 7 days is lifespan of fixer in open trays.
squirrel$$$bandit
Veteran
OK, that's more like it, and closer to my experience.
How long does an opened bottle of concentrate actually last for you, palec?
How long does an opened bottle of concentrate actually last for you, palec?
gliderbee
Well-known
I don't know if it is the same for all fixers, but I'm developing B&W (and fixing, of course 
) some 35 years now, and I always did about 20 films with one liter of fixer, but that may have varied from 15 to 30; if I look at my old negatives (I still have them all), they all look perfect to me.
Weren't there also those testpapers for fixer ? I think I used them in the past.
Stefan.
) some 35 years now, and I always did about 20 films with one liter of fixer, but that may have varied from 15 to 30; if I look at my old negatives (I still have them all), they all look perfect to me. Weren't there also those testpapers for fixer ? I think I used them in the past.
Stefan.
heespharm
Member
as long as they are fixed properly they should last a long time... the quality of fixer doesn't matter in longevity... only the quality of the fixing... so even if the fixer is degraded a little as long as the emulsion is gone it should be okay
palec
Well-known
With my rhythm of shooting and developing about 1 year until I need to open a new one (1 l) - I use different fixer for printing - Tetenal Odorless. But it can last much longer, as has been already stated - while it clears the film it still works.
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dfoo
Well-known
2 rolls? What a waste. I use 2L of 1:3 rapid for 50 rolls of 135. Only time I ever had a problem was when I mistakenly mixed 1:9 and underfixed some film a couple of years back.
jmcd
Well-known
I use Ilford Rapid Fixer, and use it until near exhaustion. I know it is working well because I test the time it takes to clear a piece of film.
Clip a small strip of film, leader or whatever, and place a drop of fixer in the middle of the film near the end. Let it sit there until the film clears. Then, watching your timer, dip the film in and out of the fixer until the film clears—this will be obvious because it is being compared to the previously cleared dot. For Ilford films in fresh fixer 1:4 the clear time is around 20 seconds. For Foma films the time is around 12 seconds. Kodak takes longer. This clear time will remain nearly constant as you process more films, until the fixer nears exhaustion. Then clearing times will take significantly longer. When clear time approaches double, the fixer is exhausted.
Clip a small strip of film, leader or whatever, and place a drop of fixer in the middle of the film near the end. Let it sit there until the film clears. Then, watching your timer, dip the film in and out of the fixer until the film clears—this will be obvious because it is being compared to the previously cleared dot. For Ilford films in fresh fixer 1:4 the clear time is around 20 seconds. For Foma films the time is around 12 seconds. Kodak takes longer. This clear time will remain nearly constant as you process more films, until the fixer nears exhaustion. Then clearing times will take significantly longer. When clear time approaches double, the fixer is exhausted.
squirrel$$$bandit
Veteran
So are you saying that if it looks good when it comes out of the wash, it's going to stay that way? That is, if the fixer is totally exhausted, I'll know it as soon as I take it out of the tank?
Clovis
Established
Yes, if your fix is exhausted your film will have milky white or yellow staining when you remove it from the tank.
At this point, you should mix a new batch of fix and re-fix the negatives.
At this point, you should mix a new batch of fix and re-fix the negatives.
squirrel$$$bandit
Veteran
In that case, I've had no problems. I do tend to fix for a really long time--more than four minutes, once I've used a dilution more than say 10 times.
I'm a bit embarrassed not to have more carefully researched this fundamental piece of knowledge, but better late than never.
I'm a bit embarrassed not to have more carefully researched this fundamental piece of knowledge, but better late than never.
gb hill
Veteran
I have a bottle thats well over a year old & when I get ready to use it I time my film leader to see how long it takes to clear. Then of course multiply my time for a whole roll. I don't have a problem at all. MOF I have two bottles of Kodak stop bath I use & I know for a fact they are over 25 years old, works fine!
Benjamin Marks
Veteran
Remember: fixing is supposed to convert unexposed silver salts to a soluble salt so that they may be washed away following fixing. If you are worried about it, you can mix up a test for residual silver in your negatives and see whether your negs actually have a problem. Stroebel and Zakia recommend the following: "The test solution for residual silver salts, that is for underfixing, is a 0.2% sodium sulfide solution, which forms yellow to brown silver sulfide stains if residual silver is present." Obviously, test a clear negative (or clear portion of a throw-away negative), which was processed along with the film about which you are concerned. If there is a problem, you can always re-fix and re-wash (although admittedly it would be a pain with any serious quantity of film). Still, you could pluck out the strips of film with "keepers" and treat them first.
BTW, if your film was clearing then the fixer wasn't totally dead -- those recommendations on the bottle are really rules of thumb, in my experience.
Ben Marks
BTW, if your film was clearing then the fixer wasn't totally dead -- those recommendations on the bottle are really rules of thumb, in my experience.
Ben Marks
S
Stelios
Guest
Speaking of stop baths, does the use or no use of stop bath affect the strength of fixer? Does the fixer last longer if I use stop bath?
I never use stop bath, I just rinse with water between developer and fixer, then fix for 5 mins (maybe more if the film comes out too purple) continuous inversion and I won't use the same fixer for more than 4 rolls (1:4 mix). Maybe I'm just wasting fixer?
I never use stop bath, I just rinse with water between developer and fixer, then fix for 5 mins (maybe more if the film comes out too purple) continuous inversion and I won't use the same fixer for more than 4 rolls (1:4 mix). Maybe I'm just wasting fixer?
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Juan Valdenebro
Truth is beauty
Benjamin Marks
Veteran
Stop bath is 5% vinegar. Most rapid fixers are ammonium thiosulfate in 5% vinegar; most ordinary fixers are also vinegar based. Most developers are mildly basic. Using a stop bath means that your fixer will last longer, because its Ph will be more stable. It is not necessary though. Without it, you will be diluting your fixer by the carry-over (that is the water or developer that adheres to your film, reels and inside of the tank), probably not more than 10ml for a 2-reel tank. I doubt that amount of water will keep your fixer from working when multiplied by 2. It is more practical in a large working darkroom (newspapers of yore) or student darkroom with many users, as stop bath (vinegar) is much cheaper than fixer. I suppose it could make a difference depending on the Ph of your local water.
Ben Marks
Ben Marks
jmcd
Well-known
"So are you saying that if it looks good when it comes out of the wash, it's going to stay that way?"
If you are referring to me, that is not what I am saying. I am talking about testing the fixer for its ability to fix efficiently and without buildup of difficult compounds that occur with overuse.
The test is done on a test strip. If the test reveals that the fixer is clearing the test strip within 2x (x = clearing time of super fresh fix), it is safe to fix your negative. You want to fix your film for 2x of clear time, or a little longer. A bit longer is ok, but too much fixing is bad.
Test the fixer with your clipped leader before fixing your actual film.
If you are referring to me, that is not what I am saying. I am talking about testing the fixer for its ability to fix efficiently and without buildup of difficult compounds that occur with overuse.
The test is done on a test strip. If the test reveals that the fixer is clearing the test strip within 2x (x = clearing time of super fresh fix), it is safe to fix your negative. You want to fix your film for 2x of clear time, or a little longer. A bit longer is ok, but too much fixing is bad.
Test the fixer with your clipped leader before fixing your actual film.
jmcd
Well-known
Exhausted fixer will clear your film, but not as fast. It also contains compounds that are much more difficult to wash out. This will work in the short term, but if you are looking for a reliable method and you want to be sure, use the film clearing test.
Even better is the two-bath fixing method, but that is being super cautious and beyond the scope of this thread, I think.
Even better is the two-bath fixing method, but that is being super cautious and beyond the scope of this thread, I think.