Progressive contamination of fixer from stop bath

[jk0592]

As I was busy in the darkroom this afternoon, I noticed that the paper, being soaked in developper, leaves some developper in the stop bath. This is not a problem. But then, after staying in the stop bath, the paper transits to the fixer, and bring some stop bath in the fixer. After my printing session, I noticed that the fixer had a slight yellowish color whose origin is without doubt the indicator stop bath.

Now, does this stop bath affect either the shelf life of the contaminated fixer and/or the capacity to fix the nominal number of 8x10 sheets of paper ?
Would it make sense to use a short water bath before dipping the paper in the fixer ?

[ic-racer]

There is acetic acid (pure stop bath) already included in some fixers: http://www.digitaltruth.com/products/formulary_tech/03-0146.pdf

Others, like Ilford Hypam have Boric Acid.

Either way, getting weak acid in some fixers should not be a problem.

Not all stop baths and fixers are the same, however. What kind of fixer and stop are you using?

[jk0592]

What kind of fixer and stop are you using?
Kodak indicator stop bath, and Kodak Fixer.
I was not aware that acetic acid was present in fixers, and I thank you for this information; I will stop worrying.

[Leigh]

Fixer is designed to be used after the stop bath. Contamination is not a concern.

- Leigh

[lenser]

If it concerns you, and if you have the sink space, just add a water bath tray in between the two.

[Leigh]

I always let the print drain over the stop bath tray for a minute before putting it in the fixer.

This greatly reduces the carry-over.

- Leigh

[Dan Henderson]

Many people use alkaline fixers such as TF4 or 5. In these cases an acid stop bath is not recommended. I, like many others, use a plain water stop bath. Some people express concern that development continues in the water stop, but if you process your test strips/prints in the water stop, continued development is "baked in."

[Heroique]

I use Kodak indicator stop bath, and Kodak Fixer ... Now, does this stop bath affect either the shelf life of the contaminated fixer and/or the capacity to fix the nominal number of 8x10 sheets of paper?

Also, here’s a helpful sheet (http://www.kodak.com/global/en/professional/support/techPubs/e103cf/e103cf.pdf?id=0.1.16.14.30.14.7.14.16&lc=en
) from Kodak about how many sheets you can fix before the solution is exhausted.

It defines enough conditions to make it generally useful for most people, I think.

Depending on your personal workflow, it could be useful if you keep notes from session to session.

[jk0592]

Thanks to all for the information. I guess that the fixer that I use will not be adversely affected by the indicator stop bath that is finding it's way in it.
One thing less to worry about.