Alkaline vs. Acid fixers
this has probably been covered here before, but since I can't seem to find the threads, I ask:
What is the advantage of an alkaline fixer, as opposed to an acid one?
A film like Efke, with an old style emulsion, i.e. not pre-hardened, would surely need a hardening, acid fixer, wouldn't it? Or is that just manufacturer "market training" talking?
I do know that alkaline fixers usually washes out quicker than acid fixers, unless you're making prints and using fixer at film strength - it is supported by research by Ilford that it provides sufficient fixing with radically shortened times for both fixing and washing using this technique.
I would be delighted to hear the pros and cons of either fixer.
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There are a lot of variables to consider here. As an example, how are you processing? What developer? I use Jobo drums with Efke 25/50/100. I also use ABC Rollo Pyro, which is a staining, tanning developer. Acid fixers cut the stain. I don't need the hardener due to the tanning effect from the pyro. I prefer to keep acid out of my process for both film and prints. One using different processing/developer combinations may want to use other fixers.
The main reason to use an alkaline fixer is to prevent reduction in stain with a staining developer like pyro. Other attractions are that it eliminates the need for an acid stop (acid stop would reduce the strength of the fixer), short wash times without a hypo clearing agent step (even with T-Max), shorter toning times for prints, and TF-4 offers very short fix times.
Hardening fixers only protect the emulsion when wet, so if you wash sheet film in an open tray after fixing, there may be some advantage to a hardening fixer, but otherwise, I don't really see a need for it. If you decide to tone your negs later to increase contrast, for instance, you'll need to refix first in plain hypo to reverse the effect of the hardener. Without a hardener you can just rinse and tone.
To me the biggest benefit of using an alkaline fixer like TF-4 is the elimination of both the acid stop and hypo clearing (washing aid) baths. You only need 2 chemicals: developoer and fixer. That's it. Much much less hassle, and fewer things to keep.
The other benefits in the case of TF-4 is fast fixing time, long lasting, no acid smell and very easy to wash off. The last of these is according to Phtographer's Formulary since I cannot tell myself. Formulary says there's no need to use any washing aid. Luckily I have a local shop that sells TF-4 so no need to pay shipping from mail order. It's the only thing I use now. Cannot imagine going back to acid ever again. You must try or you won't know what you are missing.
I just switched to TF-4, question- is the white precipitate at the bottom of the bottle normal?
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I currently use both acid fix (paper) and TF-4 (film), but as soon as my paper fix goes bad, it'll be TF-4 all around (less chemicals to have around, no stop bath spills, etc...).
I have one question to add to this thread, though:
Can TF-4 be tested for saturation with Edwal's Hypo Chek?
I currently use it to test my paper fix, and it works great (I have gone through a batch of fix with it, and the silver recovery proved the Hypo Chek to be right). However, I don't know if it would work with an alkanine fixer. I could wait until my TF-4 is near exhaustion (I have put 78 rolls of film through it, and it should handle 80, so it's dang near it), but if I'd rather know for sure.
For those unfamiliar with Hypo Chek, you use it by putting two drops into the fixer. If nothing happens, the fixer is good. If a white precipitate forms, it's saturated with silver. Of course, if it doesn't work with TF-4, nothing happening doesn't tell me much.
Thanks in advance for the help, and sorry for hi-jacking your thread, Thomas.
Yes and no. Yes, it's there when you receive the bottle. No it shouldn't be there when you use it. It takes some effort to dissolve it, but it does eventually (dilluting it to working strength may help). Using distilled water may make your life easier (and chemical life longer) as well.
Originally Posted by mobtown_4x5
you need to shake the bottle very well before mixing. Once mixed up the precipitate will be gone and you will have nice clear fixer. I imagine if you don't shake the concentrate your first few baches will be weak and future ones will be strong.
Originally Posted by mobtown_4x5
I use alkaline to neutral only - except in the rare cases when I make lith prints and it's important to stop development in a fraction of a second.
The only drawback with alkaline fixer is that you shouldn't use an acid stop bath...
I have just finished my first bottle of TF-4, and it's going to be my last. The ammonium smell is far stronger than from my own recipe, without significant increase in speed or capacity.
-- Ole Tjugen, Luddite Elitist
Ole..what is your recipe for your TF4 replacement?