What do I need to be aware of when making my own fixer?

[koraks]

Is this a myth or is there experimental evidence for it?

Depends on who you ask. If you ask me, it's a myth that's rather difficult to kill. Some others may argue that they see a difference. I never did.

 

[Alan9940]

As I understand it, the main consequence of acid fixer after pyro developers is that the acidity tends to reduce the stain image, leaving a negative that's thinner and grainier (seeming) than one fixed in neutral to alkaline fixer.

I wonder if this is more myth, than actual fact. Gordon Hutchings recommends and uses F-24 (an acidic fixer.) I've used F-24 with ABC Pyro, Pyrocat-HD, 510-Pyro, and PMK for many years and never noticed any issues with my negs. IIRC, Sandy King has stated that any standard fixer can be used; at least, with Pyrocat-HD, anyway. I have seen evidence on the 'net showing how an acid fixer has stripped a bit of stain; just never seen it for myself.

 

[Raghu Kuvempunagar]

Depends on who you ask.

Now I am tempted to ask @DREW WILEY.

If you ask me, it's a myth that's rather difficult to kill.

I can see that. Also, people will argue that even if there's no effect on the stain immediately, there's no guarantee that the stain will remain stable over years.

 

[koraks]

A friend of mine told me that he suspects (or even has seen evidence) of grease marks from fingers deteriorating the stain over a period of several years. I don't know; I haven't seen it yet, but it's not impossible. All I know is that once the stain is there, it's pretty difficult to get rid of even if you try. Apparently selenium toner should do the trick...?

 

[Raghu Kuvempunagar]

I might try one of these days a rehalogenating dichromate bleach on a negative with stain and check if that removes or diminishes the stain.

 

[koraks]

Selenium toner doesn't affect stain.

I never tried it, but have always been very skeptical.

 

[Doremus Scudder]

I need a rapid one, so I guess this depends on if I can get hold of ammonium thiosulfate at a reasonable cost or not.

Whats the consequence of using a rapid fixer instead of an alkaline one when developing with Pyrocat ?

Staining developers work just fine with slightly-acidic fixers like Ilford Rapid Fixer. Using an acid stop is just fine too, most (if not all) commercial alkaline fixers are buffered enough so that the carried-over stop has no effect on the fixer.

Best,

Doremus

 

[Doremus Scudder]

A friend of mine told me that he suspects (or even has seen evidence) of grease marks from fingers deteriorating the stain over a period of several years. I don't know; I haven't seen it yet, but it's not impossible. All I know is that once the stain is there, it's pretty difficult to get rid of even if you try. Apparently selenium toner should do the trick...?

Selenium toner doesn't affect stain.

I used to rather regularly intensify negatives with selenium toner (mixed 1+2). When I started using PMK, I found that doing this effectively removed the stain and that the end result was no increased density (the added selenium density being offset by the loss of the stain density). The resulting negatives were definitely more "neutral" in color compared to original stained ones.

I haven't done this in years, but I would assume that PMK stain would still be removed with the toner at that dilution. I use bleach/redevelop for intensification of stained negatives when needed now.

Best,

Doremus

 

[DREW WILEY]

Pyrogallol permanently tans gelatin. It's not like a superficial dye. The nature of this has been intensively studied by both photographic and motion picture industries, as well as in the medical field. Most of that research is well over my head. Over the I've worked with pyro for over forty years now, and have yet to see a negative of my own where the inherent tanning stain itself noticeably diminished. There might be cases where some residual anti-halation dye fading due to either time or light exposure under enlargement, which some people might mistake for pyro stain loss. And I haven't worked with pyrocat anywhere as near as much as pyrogallol; but it's reputed to be similar.

I doubt selenium toner is "removing" anything in this respect. It is merely intensifying the silver image itself, apart from the pyro stain. The visual result would of course be slightly different, but via addition rather than subtraction.

One of my reasons for sticking with an alkaline fixer (TF4) is that it removes any residual antihalation dye of certain films more effectively than routine fixers. I also like how it saves a lot of time and fuss relative to both film and print fixing.

 

[DREW WILEY]

Gosh, Michael .... you are a brave soul indeed if you venture into its dye formation chemistry. The two aspects are directly related. Gallic acid tanning goes back thousands of years. The color effect is a least semi-permanent, itself visible thousands of years after on certain commodities. I had three years of organic chemisty and promptly forgot 99% of everything I studied. Dye chemisty is way up there in the clouds, with all kind of still unanswered questions. A lot is empirically concluded. This is in a different arena than color photographic dyes.

What you are referring to is indeed evident on the fbf margins of certain thick emulsion films (now our of production), semi-thick ones like HP4, and to a tiny extent on some modern thin emulsion films too. I don't see any edge staining of Tmax films, however. I've got an excellent feel for this because I factor any surplus stain (non-image-forming) when making supplementary masks for pyro originals, and understand how it differs with different kind of film, and also with respect to whether or not an alkaline after-bath was used (distinct from an alkaline fixer step). When not, there's substantially less of it. But it doesn't seem to fade.

One of the clues that the image stain is robust is the fact that certain practitioners have completely bleached out the silver image itself with appropriate reducers, re-fixed the negative, and then have very successfully printed off the remaining pyro stain alone, and apparently repetitively, without it fading. So don't confuse pyro's "staining" properties with conventional color stains per se. It even seems to resist UV.

Dive in if you wish; but FOR ALL PRACTICAL PURPOSES this is a NON-ISSUE. Maybe in a couple more lifetimes a shift will be evident; but I don't have that long to observe and respond.

I can't reply to Doremus because I've never used selenium intensifier at enough concentration to see a draw in the density matchup. In fact, intensification is something I rarely do. But I do know that it only impacts DMax in a tanned negative slightly, and that there's no point in overdoing it.

 

[koraks]

@michael_r and @DREW WILEY thanks for your little discussion; it actually helps making things a bit more specific (even though it's not about OP's question anymore; still interesting). Tanning and dye formation are distinct, albeit related, processes. The tanning action will be irreversible, but since the formed dyes are organic compounds, they will not be perfectly stable by definition. However, the question then becomes: what is more stable, the dyes, or the gelatin emulsion itself? Given the durability of gallic-acid-derived dyes, it may very well be the case that anything that can break them down, will also break down the gelatin matrix in which they're embedded. I wouldn't be surprised if this were the case. And yes Drew, I hear you on the remark that the involved chemistry is complex and likely not fully understood. Case in point: look at how long it took us to understand the chemistry of something as seemingly simple as iron gall ink. We've been using it for at least 2 millennia, and I'm not sure we have fully characterized the properties of the image-making compounds even today.

 

[DREW WILEY]

As you probably know, there was a very contentious three-year episode on another forum over rival pyro formulas. I've cooked up a couple special tweaks of my own, but mainly stick with PMK. I don't even pretend to be a developer chemist juggling exactly how many moles of one thing to mix with a set quantity of lemmings of another. I'm just another wild-eyed alchemist who jerry-rigs formulas until they efficiently do exactly what I want. The whole realm of pyro is filled with mystique, and maybe that's the way it's meant to be. It's what the witches in Shakespeare's Macbeth would have added to the cauldron along with eye of newt and toe of frog.

The cross-linking of gelatin, its aging, and the relation to pyro tanning is a topic most acutely studied in the medical field. Things placed in the body need to last. But even in that field, we're talking about practical lifespans, not absolutes; and hard answers are difficult to come by. Then you're got the added factor of tanning relief in certain largely-former color printing techniques. If I stopped to read even a portion of all the photo as well as medical literature on this, I wouldn't have any time left to do printing!

 

[DREW WILEY]

Koraks - you might want to read up on the infamous "White Salamander" scandal in Salt Lake City a few decades ago. A master forger of documents was at the center of this, and no form of chemical analysis seemed to be able to spot any discrepancies because he had taken great care to not only replicate exact antique ink formulas, but to acquire authentic vintage papers. But then, finally someone looking at the gallic ink under a microscope noticed how certain vintage samples had micro-cracking due to aging, while the suspect document did not, even though the ink had apparently undergone accelerated UV aging. Once that was determined, they went back through all kinds of documents he had sold for huge sums of money to other parties. Even the signatures of famous founders of the republic in certain purchased letters and so forth in the Library of Congress turned out to be plants of his own, so that, if he was selling another document, and a handwriting expert was employed to authenticate it, the standard of comparison would itself be a matching fake.

 

[DREW WILEY]

Pyrocat and Pyro G. often get lumped together in debates because they have similar effects when printing. As long as it's some kind of "pyro" generically, it seems to be fair game for a heated feud over relatively minor nuances, just like two women showing up at the same cocktail party wearing similar dresses.

 

[pkr1979]

Thanks again all.

I take it that an acid fixer is just fine for whatever use (pyro/paper/'regular' film developing)... But what about the alkaline fixer, can that be used in the same situations? If so, why isnt it as common? Or maybe it is.

Cheers
Peter

 

[DREW WILEY]

Time is money, so it makes sense to me personally to use alkaline TF4 Archival Fixer for both for film and paper. To others, price per gallon seems to be the priority, and they stick to ordinary fixers. Or maybe they just don't know there's more efficient way to do it.

 

[koraks]

Koraks - you might want to read up on the infamous "White Salamander" scandal in Salt Lake City a few decades ago

Thanks Drew, that sounds like an interesting story for sure! It resembles one I once read about that must have been earlier, if memory serves somewhere in the 1930s. I think it culminated in a building burning down with the perpetrator locked in it...

 

[Donald Qualls]

If Kodak’s Flexicolor Fixer is still available, people have also used that.

Unique Photo sells this, and if you don't mind the fact you have to buy enough to make 20L, it's pretty economical. The concentrate keeps well, too, so you don't wind up with it going bad in the jug unless you really, really don't use much fixer.

 

[DREW WILEY]

The tanning effect of pyro inherently makes the emulsion tougher. No need for a "hardening" fixer. Workflow wise, I'll just repeat that alkaline TF4 is better at removing residual anti-halation dye for either pyro or non-pyro workflows, and that it dramatically reduces the time and fuss involved in paper fixing, less so in film fixing; but it's still more convenient for film. The only down side is that it does cost significantly more. But you need to recognize that the listed price for quart or gallon is for the concentrate, which is diluted 1:3 for actual use, and always for one-shot use. It was sold by the local camera store pre-covid. Freestyle had it, perhaps still does. But it's easy to get shipped directly from Photographer's Formulary.

 

[DREW WILEY]

Michael - I did differentiate film and paper fixing. With paper, it's dramatically faster. No need for hypo clearing agent or double fixer baths. But "Just TF marketing" pertaining to residual dye clearing - nonsense. I've observed it myself thousands of times. Besides, they're not the kind of company that resorts to BS marketing. They don't need to. TF-5 is not alkaline.

If TF4 has settled down a long time, stuff sticks to the bottom of the jug. I just decanter a little fluid, put a long wooden dowel in there and stir up the bottom a few minutes, then pour the balance of liquid back in, shake it a little, and then only minor shaking is needed thereafter. No big deal. Less fuss than mixing your own fixer from powder.

 

[Rudeofus]

I take it that an acid fixer is just fine for whatever use (pyro/paper/'regular' film developing)... But what about the alkaline fixer, can that be used in the same situations? If so, why isnt it as common? Or maybe it is.

The biggest disadvantage of acidic fixers are their limited life both as concentrate and working solution. Even sealed commercial rapid fixer concentrate (typically having a pH around 5.5) will sulfur out within a year or two, while neutral or alkaline fixer lives almost indefinitely, even as working solution. A slightly less prominent disadvantage of acidic fixers is, that they etch silver. If you leave a print halfway in acidic fixer, you will detect noticeable bleaching after an hour.

The biggest disadvantage of alkaline rapid fixers is their Ammonia smell. At pH 8.0 and above Ammonia will escape from the liquid as gas, which makes the fixer very unpleasant to use in open trays.

Neutral fixer is mostly odorless, shares the long shelf life of alkaline fixers, and it does not etch silver. Yes, you will need a stop bath between developer and fixer, but apart from that I see no reason to use anything else. Neutral rapid fixer are easy to mix yourself, but also available as packaged products.

 

[Raghu Kuvempunagar]

Even sealed commercial rapid fixer concentrate (typically having a pH around 5.5) will sulfur out within a year or two, while neutral or alkaline fixer lives almost indefinitely,

Does increasing the alkalinity of commercial rapid fixer concentrate to around 7 by adding suitable amount of Sodium Hydroxide help in increasing the longevity of the concentrate?

 

[Rudeofus]

Does increasing the alkalinity of commercial rapid fixer concentrate to around 7 by adding suitable amount of Sodium Hydroxide help in increasing the longevity of the concentrate?

I have every reason to assume it does. If you look at Ryuji Suzuki's neutral rapid fixer, that's about is simple as it gets, and it lasts forever. Commercial rapid fixer at pH 5.5 does not contain any specific ingredients to bring down its shelf life, it's just its low pH.

BTW I recommend you use Ammonia solution instead of Sodium Hydroxide to raise pH. Small amounts of sodium ion won't hurt, but if you need more, and together with the already present Sodium Sulfite it may decrease the capacity of your fixer.

 

[john_s]

Does increasing the alkalinity of commercial rapid fixer concentrate to around 7 by adding suitable amount of Sodium Hydroxide help in increasing the longevity of the concentrate?

I have every reason to assume it does. If you look at Ryuji Suzuki's neutral rapid fixer, that's about is simple as it gets, and it lasts forever. Commercial rapid fixer at pH 5.5 does not contain any specific ingredients to bring down its shelf life, it's just its low pH.

BTW I recommend you use Ammonia solution instead of Sodium Hydroxide to raise pH. Small amounts of sodium ion won't hurt, but if you need more, and together with the already present Sodium Sulfite it may decrease the capacity of your fixer.

You don't need much sodium hydroxide, so maybe the additional sodium wouldn't be too serious.

 

[Raghu Kuvempunagar]

About 60ml/l of 25% Ammonia raises pH of Ilford Rapid Fixer to ~7.