cosmonaut
Well-known
How many times can you reuse fixer? I make up a quart when I mix it up, powder type. How much do I increase times for each run?
hairy_paperclip
Member
Are we talking film or paper? What kind of fixer, what brand? If you're fixing film then take a piece of undeveloped film and drop it in your fixer. The time it takes the film to clear is called your clearing time, double that time for your fixing time. In general if it takes longer than 2 minutes to clear then it's time to soup some new fix. Also, use a product called hypo check to determine if your fixer is exhausted or not, it works on all silver fixers that I know of.
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cosmonaut
Well-known
It is Kodak fixer, powder type that mixes up a gallon. It is for film. I have a small tank and only develop one roll at at time. In the past I have used it twice. First time I fix for 5min, second time for 7min. I was just wondering could I run it a third and fourth time.
Clovis
Established
I use Ilford Rapid Fix, similar to Kodak's powder-mix rapid fix, and the Ilford data sheet states that the Fix has a capacity of around 24 rolls of 36 exp film. I usually reuse the Fix for around 20 rolls before mixing a new batch.
It's obvious when film is improperly fixed as it appears milky white/yellow, and it's really quite easy to re-fix the film if you accidentally used exhausted fix.
It's obvious when film is improperly fixed as it appears milky white/yellow, and it's really quite easy to re-fix the film if you accidentally used exhausted fix.
cosmonaut
Well-known
Thanks for the info. Is rapid fix better? I need to order more fixer, could be time to try something new.
jmcd
Well-known
As reported above, you can fix about (17-) 20 rolls per liter.
Here is a test, to be sure:
1. Take a clipped leader from the film of your choice, and place a drop of freshly mixed fixer on the emulsion. Wait until this drop clears a spot.
2. Note the clock, and dunk the same end of the film (including the cleared dot) into your fixer, lightly agitating. Comparing the clearing area to the cleared spot, it will be obvious when the film clears. (With my Ilford Rapid Fix this is 20 seconds with my HP5+; with my TF-4, this is 15 seconds. Different films result in different clear times).
3. Fix for three times of the clear time.
4. When a test leader takes twice as long to clear as the initial clear time, the fixer is exhausted. (The clear time will stay very similar until significant silver builds up, say up to 15 rolls, then clear time will rapidly increase with subsequent rolls.)
Here is a test, to be sure:
1. Take a clipped leader from the film of your choice, and place a drop of freshly mixed fixer on the emulsion. Wait until this drop clears a spot.
2. Note the clock, and dunk the same end of the film (including the cleared dot) into your fixer, lightly agitating. Comparing the clearing area to the cleared spot, it will be obvious when the film clears. (With my Ilford Rapid Fix this is 20 seconds with my HP5+; with my TF-4, this is 15 seconds. Different films result in different clear times).
3. Fix for three times of the clear time.
4. When a test leader takes twice as long to clear as the initial clear time, the fixer is exhausted. (The clear time will stay very similar until significant silver builds up, say up to 15 rolls, then clear time will rapidly increase with subsequent rolls.)
Freakscene
Obscure member
Buy a rapid (ammonium thiosulfate) fixer. Modern films contain a lot of silver iodide, which old style sodium thiosulfate fixers don't fix as well.
You can re-use fixer, but it will keep fixing film a long time after it no longer archivally fixes film. The fixer will appear to continue to fix, but more slowly, but beyond 3 g/L silver in sodium thiosulfate fixer and 5-6 g/L silver in rapid, ammonium thiosulfate fixer, incomplete fixing reaction products that cannot be washed out remain in the emulsion. These are invisible until the unwashable residues oxidise the image forming silver and turn into a visible stain.
A potassium iodide test (Kodak FT-1 solution, see Kodak publication O-3:
http://wwwau.kodak.com/global/en/professional/support/techPubs/o3/O3wp.jhtml ) will tell you if too much silver is in your fixer.
Marty
You can re-use fixer, but it will keep fixing film a long time after it no longer archivally fixes film. The fixer will appear to continue to fix, but more slowly, but beyond 3 g/L silver in sodium thiosulfate fixer and 5-6 g/L silver in rapid, ammonium thiosulfate fixer, incomplete fixing reaction products that cannot be washed out remain in the emulsion. These are invisible until the unwashable residues oxidise the image forming silver and turn into a visible stain.
A potassium iodide test (Kodak FT-1 solution, see Kodak publication O-3:
http://wwwau.kodak.com/global/en/professional/support/techPubs/o3/O3wp.jhtml ) will tell you if too much silver is in your fixer.
Marty