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Hello, a few questions about TF4 alkaline fixer and stop bath

bryans_tx said:
I have the TF-4 as the complement to 510-Pyro.
The Acetic acid has lived in a kitchen cabinet for a long time, never opened !! lol
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If, for whatever reason, you want to stay alkaline throughout the process, then a stop bath made from 100 g/l KBr + 20 g/l NaHCO3 has near infinite shelf life and can be set at any pH you want, e.g. near neutral slightly alkaline with Sodium Bicarbonate alone, slightly more alkaline by adding Sodium Carbonate.
 
I always use a MILD acetic acid stop bath prior to fixing to minimize the risk of uneven highlight development, which can otherwise occur with certain fussy papers. For film development, I simply add a brief supplemental plain water rinse step between the acid stop and fixing. TF4 has enough buffer capacity to handle a small amount of acidic carryover without any issues. This has been my go-to fixer for a long time, and is a wonderful product which saves a lot of time and water waste. But I just received a couple of gallon jugs of TF5 instead, so I can compare the two.

What sits on my own shelf seldom opened is the sodium hydroxide. And the pH meter rarely gets used either. I'm just so comfortable with my standard workflow and favorite products, like PMK developer and TF4 fixer, that I don't even think about it much anymore.
 

Ah, this is great, basically a bath saturated with bromide so the developer can’t put any more of it into solution. I like it.
 
relistan said:
Ah, this is great, basically a bath saturated with bromide so the developer can’t put any more of it into solution. I like it.
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Saturated is probably not the ideal composition. You could dissolve a lot more KBr, but you would inadvertently create a fixer instead of a stop bath. Halides are known to form soluble silver complex, if they are present in sufficient quantity, there are even fixer patents for concentrated iodide solutions.

The number 100g was suggested to me by Ron Mowrey, who, unlike me, tested it, and I would be careful before going far above this amount.
 
Tim Stapp said:
??? Please explain why not when every film/chemical manufacturer states to use a stop bath between developer and fix?
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Devil's Advocate here.

I am looking at the instruction sheet included with a pack of "THE PMK PYRO FILM DEVELOPER" printed by Photographer's Formulary.

Quote
"A plain water stop bath is excellent for all normal films and developers. Use a large volume of water and agitate roll and sheet film continuously. Use of an acid stop bath will strip the pyro stain."

Have a nice day.
 

I’ve never seen this stuff, but I don’t like the idea of undissolved particles around my films. I always filter solutions before use, to help limit the amount of retouching to be done on prints.
 
snusmumriken said:
I’ve never seen this stuff, but I don’t like the idea of undissolved particles around my films. I always filter solutions before use, to help limit the amount of retouching to be done on prints.
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TF4 has a component that is semi-opaque and tends to settle to the bottom of the jug (the concentrate, NOT the diluted working solution!). It is clearly stated on the bottle to SHAKE WELL before using. Once mixed with water, the solution clears and there is no separation of components. There are no “undissolved particles”.
TF4 is a superior fixer in many ways, including the fact that film washing is significantly faster: 5 minutes and you’re done. It’s all I use now.
 

Agreed. I routinely use citric acid as a stop with films developed in Pyrocat-HD and it has no apparent affect on the stain.
 

Ok, thanks for explaining that. Sounds much more interesting now.
 
Yes and those solids take quite a while to dissolve when mixing up the working solution at room temperature, so be patient.
 

Does anyone know what the undissolved sediment in the concentrate is? I ask because I add ammonia solution to Ilford rapid fixer to bring the pH up a bit (approaching neutral but not quite 7).
The undiluted modified fixer throws a white deposit which, like the TF4, dissolves readily when diluted to working strength. It's not a problem as long as I ensure complete mixing, but that is a bit inconvenient if I'm diluting a small amount, as I have to shake up sometimes the whole 5L.
 
I've used an acid stop bath with every pyro developer I've ever tried, pyrog. or pyrocat. No problem. Certain EU films had emulsions quite sensitive to too much acidity. But that's a different issue. It doesn't take much pH change get the job done. I never reuse any developing chemcals, including stop or fixer; so my one-shot usage is only around 1/2 % acetic acid at the most.
 

Interesting, well the next step in a negative process would be fixing anyway so precision may not be as important.
 
relistan said:
Interesting, well the next step in a negative process would be fixing anyway so precision may not be as important.
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If you get carryover developer into something, which acts as a strong, but low capacity silver solvent, and which may already be loaded with silver from previous runs, then staining is a likely option. Even 100 g/l KBr is too expensive for single shot processing.
 
I had my first experience with TF5 fixer today, in conjunction with FP4 sheet film and PMK developer. It worked just like TF4, except that I got emulsion edge frilling - something I have never seen before with FP4 in my life. It was only at the very margins of the sheets, and not into the image area at all, so these are still perfectly printable. But it sure took me by surprise. Next time I'll try an extremely weak acetic acid stop bath, like I once used for Efke film, and see what happens.
 

Siri stop it's usually mixed to a 2% solution.
 
Traditional 2% seems to have had a considerable amount of excess usage in mind. Since I use the stop one-shot, even 1/2% is plenty strong.
 
DREW WILEY said:
Traditional 2% seems to have had a considerable amount of excess usage in mind. Since I use the stop one-shot, even 1/2% is plenty strong.
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Probably depends on the developer you use. D-8 will require different stop bath concentration than Rodinal 1+100.
 

Bill Troop has said it is unlikely to get dichrotic fog with modern films.
 
The home mixed TF-2 is similar to TF-4. It is a rapid alkaline fixer. I have used it with film. The ammonia smell is a bit more than TF-4 & TF-5 so is good for tanks but not for paper or open trays. It is inexpensive. I now use TF-5 which I think is the premier fixer. I am in the no stop bath for film camp because the arguments for using stop have not seemed persuasive to me.
 
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bluechromis said:
Bill Troop has said it is unlikely to get dichrotic fog with modern films.
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He's probably right. Perhaps with the exception of Shanghaifilm , which appears to behave like a really old-fashioned (1950s-1960s style) film in a couple of ways. One of these is the ease with which it can develop dichroic fog.
 
bluechromis said:
The home mixed TF-2 is similar to TF-4. It is a rapid alkaline fixer. I have used it with film.
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TF-2 is not a rapid fixer and therefore quite inferior to TF-3/4/5. TF-3 was the last one of Bill's fixers with a public formula.


I would expect TF-3 and TF-4 to reek to high heaven in an open tray, but TF-5 should be completely odorless at pH 6.5.
 

Around pH 6.5 is definitely the sweet spot for odour minimization.
 
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