Pre testing paper fixer

When preparing to develop negative film I am in the custom of testing my working fix solution with a piece of film prior to developing to see how long it takes to clear in relation to the recommendation of the fix manufacturer. In my case I am using TF-4 fixer and it is recommended to fix film for 3-4 minutes. My film tests indicate the film will clear in about 30 seconds so I feel okay about it.

When printing Fiber paper and the recommendation is 1 minute, how long would it take to clear a piece of FILM in the paper fixer? I can wait until the print is finally washed and use a Residual Hypo Test Solution but then that's a little late to learn it was not adequately fixed. It would be better to learn you have a weakened fixer before using it.

Any suggestions?

Your reference to judge the state of your fixer is not the recommended fixing time; It is the film clip clearing time, measured when the fixer was freshly prepared. When that time has doubled, discard fixer. Also, residual hypo has not much to do with fixing time; rather with washing time.

The clearing time 'test' for film fixing is basically wrong. All this indicates is whether your fixer is still capable of clearing the silver in a film. This is something that fixer can achieve long after it is truly effective in doing it's job.

There is only one way of establishing if your print fixer is still effective and this is by using test strips designed for this process.

You have to understand that there are three variables:

Is the fix good enough to fix my print (to meet basic recommendations).

Is the fix good enough to fix my print (to meet basic commercial standards).

Is the fix good enough to fix my print (to meet archival standards)

It is your choice - I work to archival standards because I believe my clients (those who buy my prints) are entitled to expect this from me.

Bests,

David.
www.dsallen.de

I was just looking for a quick and simple way help decide when it is time to change fixer before wasting a print to find out after the fact. I make quite a few test strips/work prints prior to the final print and trying to count the amount of paper that has gone through a batch of fixer is just silly.

Thank you all for your insights, they are all helpful.

Bruce

Use the test designed for retained Silver. It will tell you when the fixer is bad.

OR, use a piece of film to determine how long your fixer takes to fix it. Use that value and when it goes up 2x increase fix time 2x and etc. Of course, the retained Silver test along with this will help you along. At around a 2x increase in film fix time, you will want to consider discarding the fix, but remember that fix is cheap but your pictures are not. They are priceless.

PE

Thanks again everyone.

I think for my purposes I will use the film clearing time from new/fresh paper fixer to twice that time and see how long it will go. Then maybe add the Residual test for film.

Bruce Osgood said:

Thanks again everyone.

I think for my purposes I will use the film clearing time from new/fresh paper fixer to twice that time and see how long it will go. Then maybe add the Residual test for film.

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Bruce:

Do you use fixer at the same dilution for both film and paper?

If not, film clearing times won't work for paper fixer.

Hi Matt;

Yes, I use TF-4 at 1:4 for both. I am only looking for an indication of when the paper fix has weakened, not if the print is properly fixed. I don't know what that time should be but I know fresh Paper fix will clear a neg is <30 seconds. When it takes 1 minute to clear I would consider mixing new.

APUGuser19 said:

I wonder why rapid fixer had paper and film dilutions, but good old plain Kodak Fixer works for everything.

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Well, I don't know. I know the TF-4 recommended capacity for paper versus film is much different. It is suggested +/- 30 8x10 prints (2400 Sq ") per liter at 3-4 minutes and 1400-1600 Sq" film per liter at 1 minute.

Perhaps Ron will explain