Kodak Fixer Questions
I'm about to start developing film at home for the first time. I'm currently taking my first darkroom class, and it's about to end.
I have a bag of powdered Kodak Fixer (Cat 197 1746) that I got for free. In my class, we use a rapid fixer; this one's not rapid.
Here are the questions I hope you'll help me with:
1. On the bag, it says the dilution should be "1." Does that mean use it straight?
2. The time is listed as "5 - 10 minutes." I'll be developing Tri-X 400 (shot at 400); exactly how long should I fix for?
3. I'll mix up a gallon of it. Then I'll use some, and pour the used back into my gallon jug. And when I've done 12 35mm rolls (or 6 120mm rolls), it will be spent, and then I'll dispose of it. Is that right?
4. How should I dispose of it?
Thanks for your help!
Good Afternoon, Sue,
1--Use it straight as mixed.
2--The time will vary somewhat with the particular film. The T-Max films, for example, usually need a longer fixing time. When the fixer is fresh, 6 or 8 minutes for Tri-X should be OK. Just see the data sheet for the film of your choice.
3--The capacity of a gallon should be far more than 12 35mm rolls. In an old Kodak Master Darkroom Dataguide, I've found a figure of 100 8 x 10 sheets/gallon which should translate to approximately the same number of either 35mm or 120 rolls. That assumes, of course, that you don't exceed the shelf life of about 2 months for the mixed solution.
4--Small amounts can ordinarily be disposed of safely by dumping down the drain.
not sure where you are located but do not dump the fix down the drain. Any local pro lab or school will have a silver recovery unit that should accept your spent fix for free.
a good way of testing if your fixer is still good is to save the piece of film that you cut off before you reel it up.
Put one of those film pieces in your fixer and measure how long it takes for that piece of film to clear. Double that time and that's your fixing time. If it takes a very long time to clear the film strip, or it doesn't clear at all, it's about time to get rid of it.
This helps to maximize the potential of your fixer's lifespan.
Originally Posted by suebrown
"Often moments come looking for us". - Robert Frank
"Make good art!" - Neil Gaiman
"...the heart and mind are the true lens of the camera". - Yousuf Karsh
Thanks for all your help, everybody. I appreciate it.
Sponsored Ad. (Subscribers to APUG have the option to remove this ad.)
Fixer can be used much diluted. You would need to know how much of the
working strength solution is needed to do the job then dilute to the volume
needed. I use fixer very dilute to near it's capacity then toss it; one-shot
Do parcel out that gallon into smaller amounts and keep the caps on tight. Dan
For the kind of fixer you have Sue, Do Not dilute it. Use it full strength only. You can count the number of rolls of film or sheets of paper, that you have processed, and discard it when you reach that amount. The film test huggyviking describes is a good way of checking your fix.
[COLOR=Sienna][FONT=Arial]Some days are diamonds. Some days a tree crashes through your roof.[/FONT][/COLOR]
The capacity of fixer depends on whether or not you want your films to be archival. The build-up of silver in the fix as films are fixed prevents the full removal of silver halide and other unwanted complexes. According to Grant Haist (ex EK research director) the capacity of fixer is as little as two films per US gallon if archival fixing is required.
Two-bath fixing greatly extends fixer capacity - one US gallon can fix 20 films archivally if it is split into two baths, and a wash used between the two baths. Ask for more details if you want them.
Under-fixing must be avoided. Over-fixing a little isn't a problem.
These capacities refer to films with no silver iodide - which includes Tri-X as far as I am aware. T-Max films exhaust films more rapidly - I count one T-Max film as two when I log my fixer use. Here's what EK say about T-Max: "Your fixer will be exhausted more rapidly with these films than with other films. If your negatives show a magenta (pink) stain after fixing, your fixer may be near exhaustion, or you may not have used a long enough time. If the stain is slight, it will not affect image stability, negative contrast, or printing times. You can remove a slight pink stain with KODAK Hypo Clearing Agent. However, if the stain is pronounced and irregular over the film surface, refix the film in fresh fixer."
Here are the terminology references when speaking of these:
You have your Powder solution, or your Concentrate (liquid). Once you mix it up for storage (unless concentrate), you'll have what’s called, Stock solution. Once you mix up the stock solution to be used, it is called the Working solution.
On packages, if there is no dilution necessary, it will indicate 1 rather than a ratio. Or it will say Full or Stock. If dilution is necessary, it will say 1:1 or 1:2 (1 part chem:1 part water). Most hand agitation tanks are 800ml, so if the necessary working solution is 1:1, then it would be 400ml:400ml.
In reference to your fixer, since it is not rapid fixer, fix it for 10 minutes. Your working solution will be stock (for prints it's 1:1). Make sure you use hypo clearing agent to reduce wash times to 5 - 10 min rather than 1 hour. Your working solution is 1:4 for Hypo Clearing.
The math I use is, add the two ratios up and divide it by the total capacity to get your ml for your stock solution. Then I take that number and multiply it by the remaining to get your water solution. For example 1:4 for 800mm. 1+4 = 5 / 800 = 160ml * 4 = 640ml. 160ml + 640ml (1:4) = 800ml. Very simple and useful math!
If you're developing Tri-x I would recommend pouring the fixer into a dedicated 1 quart bottle so you can reuse it the second time then toss it. For Tmax films, I usually use it once and dump it. I always try to avoid contaminating my stock solution if I can help it. Sure it is more economical in some ways, but I would not want to put a potential masterpiece negative at risk.
As any photographer will tell you: Film/Chemicals/etc is cheap. However, time is not.
Money is not the problem. The problem is, I don't have any.
I called Kodak and the NEW Tri-x will "eat up" the fixer quicker, but not as bad as T-max.
I can't figger how to upload it so do a search for "Photo binbook" look under photography-darkroom-fixing. REAL good article.