What Is The Current Thinking On Pyro And Acid/Hardening Fixers?

[chuckroast]

I have long used TF-4 for all film fixing. But I am in possession of some Efke R100 and PL100M film. This film is lovely but has a REALLY soft emulsion that literally can peel off if one is not careful when handling it wet.

I would like to use a hardening fixer like plain Kodak Fixer with this film, but I develop almost exclusively with PMK and Pyrocat-HD, the latter being mostly semistand.

There was a time when such fixers were claimed to be at odds with Pyro stain, but I've seen some back and forth on this and wonder what the current hive wisdom is on the matter.

I really want to use this film and would prefer not to resort to D-23 just to be able to use a hardening fixer.

 

[koraks]

Note that the lore goes that acid (not so much hardening) fixer would clear the stain. This however is an urban myth. Hardening will also not hurt.

The only concern with very soft emulsions like Efke is that an acid stop bath can induce carbon bubbles in the emulsion, causing damage. The film you have there is a fairly unique example of this possibility; it's not much of a concern with modern films.

So feel free to use an acidic, hardening fixer.

 

[chuckroast]

Note that the lore goes that acid (not so much hardening) fixer would clear the stain. This however is an urban myth. Hardening will also not hurt.

The only concern with very soft emulsions like Efke is that an acid stop bath can induce carbon bubbles in the emulsion, causing damage. The film you have there is a fairly unique example of this possibility; it's not much of a concern with modern films.

So feel free to use an acidic, hardening fixer.

Thanks. I've avoided stop bath for film for this very reason - older emulsions sometimes pinholed from it. I'll have to stick a pH meter into the Kodak Fix to see just how acidic it really is.

So ... with modern films, it would seem that TF-4 isn't really necessary, even with PMK, Pyocat, et al. Any old Ilford or Kodak fixer will do?

 

[john_s]

There's acid fixer, being standard rapid fixer with pH around 5.5, and there's fixer with hardener which I have read is more acidic, necessary for the hardener (alum) to work. Could you use a separate hardener, like one of the formaldehyde ones?

 

[Steve Goldstein]

<snip>
The only concern with very soft emulsions like Efke is that an acid stop bath can induce carbon bubbles in the emulsion, causing damage. </snip>

Would a buffered stop bath around pH 5.5 prevent the bubbles?

 

[john_s]

........

The only concern with very soft emulsions like Efke is that an acid stop bath can induce carbon bubbles in the emulsion, causing damage. ................

I remember reading that carbon dioxide bubbles that cause this sort of damage occur when the developer contains carbonate (carbonate + acid = fizzy bubbles) but not developers without carbonate. The pyrocat-HD has carbonate, of course, though it's rather dilute. Maybe a rinse with plain water before the next bath that's acidic would be enough?

 

[john_s]

Maybe some ideas here

Alum Hardener formulas for use BEFORE developing on soft emulsions?

Hi, Are there any film hardener formulas based on non volatile not very toxic reagents (alums, aluminium chloride etc) that can be used BEFORE the developing step to harden films with softer emulsions (Efke etc). The film developing cookbook gives a glutaraldehyde formula but I would like to...

www.photrio.com

 

[Alan9940]

I've used home mixed F-24 for many years with several different pyro formulas and I've never had any problems. Gordon Hutchings in his tome "The Book of Pyro" recommends and personally uses F-24. I know a couple of photographers using standard Kodak fixer. IMO, no need to worry.

 

[koraks]

Any old Ilford or Kodak fixer will do?

Certainly. Just use any old fixer.

The pyrocat-HD has carbonate, of course, though it's rather dilute. Maybe a rinse with plain water before the next bath that's acidic would be enough?

Yes, a water rinse instead of a stop bath should be fine. Good point about the carbonate/carbon dioxide. Note that most developers use some form of carbonate as part of the activator - but not all (rodinal comes to mind).

Would a buffered stop bath around pH 5.5 prevent the bubbles?

I wouldn't risk it with this particular film. The carbonate reaction will still occur just as well as in an unbuffered stop bath. The pH of the stop bath will just not drift as rapidly. I don't think the higher pH of a 5.5 buffer will be a safeguard against the bubble issue on this film.

 

[juan]

My experience with Efke PL100 and X-Ray film are that the hardening provided by Pyrocat is sufficient to avoid scratches. My thought is that hardening with the developer is better because it comes earlier in the process. I still mix up my own TF-2 non-hardening fixer and plain water stop.

 

[retina_restoration]

A Pyro developer will harden the emulsion quite a bit, long before it gets into the fix, so just use water as the stop, and any fix will be fine. Comments above about stripping off the stain are correct: turns out that's just a myth.

 

[Carnie Bob]

I have always used a water stop and a non hardening fix before the stain>

 

[Andrew O'Neill]

I've used acid (rapid) fixers for years with several staining developers, including Pyrocat-HD, and 510-Pyro. It makes zero difference. I made a video about it a while back. Should be posted somewhere in Photrio...

 

[Ian Grant]

I did some tests a few years ago with prints. I have used an Ilford Toner IT-8 since around 1977, it's a Dichromate re-halogenating bleach and simple Pyrocatechin re-developer. I began using Purocat HD for negative development around 2004, and realised I could use it for toning as well, So I did a series of tests bleaching and toning prints then cut them in half,washing half with water then an alkali fixer, the other with stop bath and Ilford Rapid Fixer, there was no difference.

Ian

 

[Tumbles]

When I first started using Pyrocat, I used a 1/4 strength Kodak stop bath and either Ilford Rapid Fixer or homemade Agfa 304 Fixer. At the time I didn't really want to redo all my chemistry for Pyrocat. Later on I start using a water stop bath and TF-4 Fixer, and I saw a noticeable increase in stain. This my experience, anyways.

I just processed some Efke IR820 in Obsidian Aqua with TF-4 Fixer. Everything looks good as far as the emulsion staying attached to the base. I'm guessing the hardness should be similar to Efke 100. Still, I've only done this once.

 

[chuckroast]

When I first started using Pyrocat, I used a 1/4 strength Kodak stop bath and either Ilford Rapid Fixer or homemade Agfa 304 Fixer. At the time I didn't really want to redo all my chemistry for Pyrocat. Later on I start using a water stop bath and TF-4 Fixer, and I saw a noticeable increase in stain. This my experience, anyways.

I just processed some Efke IR820 in Obsidian Aqua with TF-4 Fixer. Everything looks good as far as the emulsion staying attached to the base. I'm guessing the hardness should be similar to Efke 100. Still, I've only done this once.

I just ran a test roll of old Tri-X to check out a camera and semistand processed it in Pyrocat-HD 1.5:1:300, used a water rise for stop bath, and fixed in standard Kodak Fixer for 6-7 mins. The stain look entirely normal.

 

[DREW WILEY]

pyrogallol is a tanning process which partially hardens on its own. I presume pyrocat is similar, but have personally used less of that. I have never had a need for any supplementary hardener. I do like archival fixers for not only their time saving, but better removal of residual antihalation dye stain. Previously I used TF4, but have since learned that TF5 works just as well, yet is more convenient.

Emulsion loss on Efke films was generally the result of too strong of an acetic acid stop bath. Don't use anywhere near 2%. Even 1/4% should work if you use it one-shot.
Another potential cause is too warm a solution temperature. Stay below 75F.

 

[Mark J]

I've used acid (rapid) fixers for years with several staining developers, including Pyrocat-HD, and 510-Pyro. It makes zero difference. I made a video about it a while back. Should be posted somewhere in Photrio...

I saw that not long ago, it was very helpful.
I'll be going back to Hypam this year.
John Wimberley has stated that there's no need to use alkaline fix on WD2D, Wd2D+ or WD2H .
I tend to use my stop solution diluted to 1/2 or 1/3 normal strength and discarded when I dev with Pyro, whether or not this is important, I can't tell you.

 

[chuckroast]

I saw that not long ago, it was very helpful.
I'll be going back to Hypam this year.
John Wimberley has stated that there's no need to use alkaline fix on WD2D, Wd2D+ or WD2H .
I tend to use my stop solution diluted to 1/2 or 1/3 normal strength and discarded when I dev with Pyro, whether or not this is important, I can't tell you.

I long ago switched to water rinse for stopping the development. So long as you match temps reasonably close, you completely avoid any byproducts of shoving an alkaline negative into acid.

 

[DREW WILEY]

Water by itself doesn't work all that well with some films. The days of old thick-emulsion films are gone, which would retain solutions longer. But a few are still semi-thick, like HP5 and Tri-X 320.

However, I often use a brief water rinse between the acid stop and the alkaline fixing phase. It's probably not necessary, but can't hurt either.

 

[chuckroast]

Water by itself doesn't work all that well with some films. The days of old thick-emulsion films are gone, which would retain solutions longer. But a few are still semi-thick, like HP5 and Tri-X 320.

However, I often use a brief water rinse between the acid stop and the alkaline fixing phase. It's probably not necessary, but can't hurt either.

I typically use continuously running water, or multiple water exchanges in a tank in rapid succession. I've never seen an issue as a result.

 

[Doremus Scudder]

I long ago switched to water rinse for stopping the development. So long as you match temps reasonably close, you completely avoid any byproducts of shoving an alkaline negative into acid.

The whole point of using an acid stop bath is just that: "shoving an alkaline negative into acid." The result is a quick and effective "stop" of developer activity. Yes, there are problems with some soft-emulsion films and a too-strong acid stop. Yes, water will do the job too, with time (and care, since you can't use a water stop for more than a couple times before it becomes alkaline enough with carried-over developer to not be able to do the job any more). But, for most films, an acid stop at the recommended strength won't hurt a thing. And, it is fine with most alkaline fixers as well. It all boils down to convenience.

There's nothing wrong with a water stop if you give it enough time and make sure the water is fresh enough to do the job. It's easy with roll-film tanks, especially if you're only processing a few rolls. The point of an acid stop is to be able to stop quickly and to use it for a larger throughput and in total darkness without having to change it. For processing lines with tanks or for tray-processing larger batches of sheet film, an acid stop tank/tray is a lot more convenient. And, if you're using an acid fix, like Ilford Rapid Fixer, then the acid stop extends fixer life as well.

Best,

Doremus

 

[john_s]

I typically use continuously running water, or multiple water exchanges in a tank in rapid succession. I've never seen an issue as a result.

Me too. If you use highly diluted developers, the water rinse is probably more effective than in the case of "full strength" developers like D-76 etc, in which case a bit more time and agitation is probably called for. My two developers are Pyrocat for most things and ID-68 (Microphen) for fast moving grandchildren. In no case have I seen just water "stop" be suboptimal. Note: not the same situation with FB paper!

 

[Mark J]

Well, I remain unconvinced. It appears to be more work and time, and I'm still not clear what it is you are trying to avoid.