TF-3 Precipitate problems
I've been using TF-3 (Anchell's Darkroom Cookbook recipe) for years for printing on Ilford MG Fiber paper. Some recent batches of the ammonium thiosulfate solution used in TF-3 arrived with, or since thrown, a white precipitate. I assumed that this was just colloidal sulfur and would cause no problems provided that the prints were well-washed, which they are.
I did some local bleaching with a dilute ferricyanide solution, followed by another fixing in fresh TF-3. After washing and drying the prints, I noticed that the areas I bleached had a whitish haze in the dark tones which is apparently in the emulsion itself, not on the surface, since it cannot be wiped off. I speculate that the ferricyanide reacted with the TF-3 and caused the white precipitate to form in the gelatin. I have never seen this effect before after doing local bleaching.
To be exact, my process was as follows:
Develop in D-72
Citric acid stop bath
Two-bath fixation in TF-3 (2 liters each)
Wash for one hour
I assume that the citric acid in the stop bath gradually neutralizes the alkali and sulfite in the TF-3, but I make fewer than 10 11x14's in a session and throw the first bath out at the end. In the past, I've never noticed the first bath getting murky while using it, but the thiosulfate solution I used in the past was never murky to begin with.
In the bleaching in toning session I followed this procedure:
Soak the prints in water
Put the print to be spot-reduced in fresh TF-3 for one minute
Move the print onto a sheet of acrylic and mop it off with a sponge
Spot-reduce with ferricyanide solution
Put the print back in the TF-3 and evaluate
Repeat previous three steps if needed
Rinse in running water for 30 minutes
Tone in selenium
Wash for one hour
I don't know the exact concentration of ferricyanide that I use but it's probably close to 0.25 to 0.50 percent or less. It works slowly enough for me to control it.
The above process left me with the hazy whitish-blue fog in the dark tones. It is the same process I've used successfully for years. In fact, there was quite a bit of the white precipitate left in my sink the next day.
I'm guessing that in order of likelihood, my problem was caused by one or more of (1) a bad batch of ammonium thiosulfate solution; I should not accept murky product in the future; (2) I let the thiosulfate spoil by letting it sit around in the vendor's bottles for 6 months or more, some bottles not full (but even the unopened bottles have schmutz on the bottom of them), or (3) the thiosulfate (sitting on the concrete floor as it does) probably spends a lot of time at 50 deg F or less during the winter months (I keep the darkroom at 55 deg F when I'm not using it) and that's too cold to store thiosulfate solution, or (4) something else.
Any ideas?
Separately, since my printing volume is so low these days, I've been thinking of chucking TF-3 entirely and using Kodak Rapid Fixer (without the hardener) or Ilford Rapid Fixer solution instead. I assume that these are both alkaline fixers. Do the concentrates keep well in partially full bottles? Any reason to prefer one versus the other?
Thanks in advance for your suggestions and advice.
Re: TF-3 Precipitate problems
Ilford Rapid Fixer and Kodak Rapid Fixer (without hardener) are functionally equivalent. They are both mildly acidic. Once opened the concentrate should last up to approx. 6 months.
Quote:
Originally Posted by
Joe O'Hara
I've been using TF-3 (Anchell's Darkroom Cookbook recipe) for years for printing on Ilford MG Fiber paper. Some recent batches of the ammonium thiosulfate solution used in TF-3 arrived with, or since thrown, a white precipitate. I assumed that this was just colloidal sulfur and would cause no problems provided that the prints were well-washed, which they are.
I did some local bleaching with a dilute ferricyanide solution, followed by another fixing in fresh TF-3. After washing and drying the prints, I noticed that the areas I bleached had a whitish haze in the dark tones which is apparently in the emulsion itself, not on the surface, since it cannot be wiped off. I speculate that the ferricyanide reacted with the TF-3 and caused the white precipitate to form in the gelatin. I have never seen this effect before after doing local bleaching.
To be exact, my process was as follows:
Develop in D-72
Citric acid stop bath
Two-bath fixation in TF-3 (2 liters each)
Wash for one hour
I assume that the citric acid in the stop bath gradually neutralizes the alkali and sulfite in the TF-3, but I make fewer than 10 11x14's in a session and throw the first bath out at the end. In the past, I've never noticed the first bath getting murky while using it, but the thiosulfate solution I used in the past was never murky to begin with.
In the bleaching in toning session I followed this procedure:
Soak the prints in water
Put the print to be spot-reduced in fresh TF-3 for one minute
Move the print onto a sheet of acrylic and mop it off with a sponge
Spot-reduce with ferricyanide solution
Put the print back in the TF-3 and evaluate
Repeat previous three steps if needed
Rinse in running water for 30 minutes
Tone in selenium
Wash for one hour
I don't know the exact concentration of ferricyanide that I use but it's probably close to 0.25 to 0.50 percent or less. It works slowly enough for me to control it.
The above process left me with the hazy whitish-blue fog in the dark tones. It is the same process I've used successfully for years. In fact, there was quite a bit of the white precipitate left in my sink the next day.
I'm guessing that in order of likelihood, my problem was caused by one or more of (1) a bad batch of ammonium thiosulfate solution; I should not accept murky product in the future; (2) I let the thiosulfate spoil by letting it sit around in the vendor's bottles for 6 months or more, some bottles not full (but even the unopened bottles have schmutz on the bottom of them), or (3) the thiosulfate (sitting on the concrete floor as it does) probably spends a lot of time at 50 deg F or less during the winter months (I keep the darkroom at 55 deg F when I'm not using it) and that's too cold to store thiosulfate solution, or (4) something else.
Any ideas?
Separately, since my printing volume is so low these days, I've been thinking of chucking TF-3 entirely and using Kodak Rapid Fixer (without the hardener) or Ilford Rapid Fixer solution instead. I assume that these are both alkaline fixers. Do the concentrates keep well in partially full bottles? Any reason to prefer one versus the other?
Thanks in advance for your suggestions and advice.
Re: TF-3 Precipitate problems
That white/yellowish precipitate is indeed sulfur; it precipitates out of the solution after a long time (years, usually). If you see it in your fixer, that means your fixer is dead and gone. Don't use it.
You might try Formulary TF-5, the newest (and IMHO the best) of the modern alkaline fixers. There's nothing wrong with the standard rapid fixers either- beyond their lovely aroma, which I've been happy to leave behind.
Re: TF-3 Precipitate problems
TF-5 is neutral (target working solution pH 6.5-7).
There are other options too. One excellent product is Sprint Record Speed Fixer, also neutral/weakly acidic. Kodak Flexicolor pH~6-6.5
Quote:
Originally Posted by
Mark Sampson
That white/yellowish precipitate is indeed sulfur; it precipitates out of the solution after a long time (years, usually). If you see it in your fixer, that means your fixer is dead and gone. Don't use it.
You might try Formulary TF-5, the newest (and IMHO the best) of the modern alkaline fixers. There's nothing wrong with the standard rapid fixers either- beyond their lovely aroma, which I've been happy to leave behind.
Re: TF-3 Precipitate problems
TF4 is alkaline. It's what I routinely use. Excellent product. But new bottles of concentrate sometimes do need to be shaken to get settled ingredients off the bottom. I NEVER re-use any kind of fixer, and always mix it up fresh, just enough for each daily session. That mitigates quite a few problems. It's fast, and no need for any second bath either.
Re: TF-3 Precipitate problems
Thanks to everyone for their helpful input. I think I'll go with a packaged fixer from now on, clearly I'm not saving any money or time rolling my own, at this point.
Re: TF-3 Precipitate problems
Quote:
Originally Posted by
Drew Wiley
TF4 is alkaline. It's what I routinely use. Excellent product. But new bottles of concentrate sometimes do need to be shaken to get settled ingredients off the bottom. I NEVER re-use any kind of fixer, and always mix it up fresh, just enough for each daily session. That mitigates quite a few problems. It's fast, and no need for any second bath either.
2nd that. I never re-use any fixer
Re: TF-3 Precipitate problems
With ammonium thiosulfate fixers, if the stock solution is too strong they tend to precipitate sulfur... Once diluted, they are safer from it...
If you look at off the shelf rapid fixer dilution tables, you will never see a stronger than 1:4 stock, as stronger will just precipitate sulfur, and even at that strength, I have made stock from scratch (1:4) that did, but never seen it happen at 1:2 working stock strength...
Try mixing your current stock to working or 1:2 stock to avoid problems... ;)
Steve K
Re: TF-3 Precipitate problems
I have a never opened gallon of TF5
Stored in 3 sheds 7 years
Still very clear, it is the last of 4 gallons I bought as shipping then was most advantageous by the case
TF5 seems to never stop clearing, I check it every usage with X-Ray cutoffs, but 'recycle' it by film surface count
https://stores.photoformulary.com/tf-5-archival-fix/
I don't know why some won't use it
I trust PE (RIP) more than any other source
Mix ONLY with Distilled water
Re: TF-3 Precipitate problems
TF-5 (PE) would certainly be my choice in a Formulary rapid fixer product.
The only reason I wouldn't use it is it is more expensive than the various other easily obtainable options that are just as good.
Quote:
Originally Posted by
Tin Can
I have a never opened gallon of TF5
Stored in 3 sheds 7 years
Still very clear, it is the last of 4 gallons I bought as shipping then was most advantageous by the case
TF5 seems to never stop clearing, I check it every usage with X-Ray cutoffs, but 'recycle' it by film surface count
https://stores.photoformulary.com/tf-5-archival-fix/
I don't know why some won't use it
I trust PE (RIP) more than any other source
Mix ONLY with Distilled water
Re: TF-3 Precipitate problems
Quote:
Originally Posted by
Mark Sampson
...
You might try Formulary TF-5, the newest (and IMHO the best) of the modern alkaline fixers. There's nothing wrong with the standard rapid fixers either- beyond their lovely aroma, which I've been happy to leave behind.
couldn't agree more with this. After years of darkroom work, I absolutely hate the smell of fixers and stop baths. TF-5 is now the only fixer I use for film and fiber.
