Photo-Flo substitute?

[sanking]

Can someone recommend a substitute for Photo-Flo that can be mixed up with things that many darkroom enthusiasts might have on hand, or pick up at the grocery store?

Sandy

 

[Ryuji]

Triton X-100 is used in cleaner products, for example, but in a small concentration. They also contain a lot of stuff other than surfactant, so I don't have any recommendation for a substitute.

One possibility is dishwasher rinsing agent, but I bet it uses very different kinds of surfactants, as they have to be food-safe, while Triton X-100 isn't.

 

[Phillip P. Dimor]

I've used a drop or two of Jet Dry as a wash aid in the past, worked well for me. Cheap and can be found at the grocery store.

 

[Photo Engineer]

Any product with dyes in them or scents tend to leave an unpleasant residue on film. Some of them are damaging due to pH.

The colorants and scents are oily and don't really do the job.

PE

 

[BradS]

I once used a drop of Dawn dish soap in store bought "Purified water". Not sure it was good or bad but seemed not to have any ill effect. Might have been just as well off with just the water.

 

[Sean]

I've been using a 3 bath distilled water soak that seems to do the trick for me. For some reason anytime I use a photo-flo type solution no matter what (or how) I try it I have problems.

 

[boyooso]

I've used glycerin, in water...but that was in a pinch, in S. Korea.

but I much prefer Ilfords' Ilfotol

Corey

 

[boyooso]

Any product with dyes in them or scents tend to leave an unpleasant residue on film. Some of them are damaging due to pH.

The colorants and scents are oily and don't really do the job.

PE

PE, can you reccommend anything that would work?

Corey

 

[Wayne]

Hmm..coulda sworn I had a reference on this somewhere but darned if I can find it. MSDS (current threads on that topic notwithstanding) shows only agua, propylene glycol and alcohol in roughly 70-20-10. How hard could that be? I guess that might depend on the alcohol, which is this little beauty: p-tert-octylphenoxy polyethoxyethyl alcohol.

 

[Ryuji]

I've used glycerin, in water...but that was in a pinch, in S. Korea.

Glycerol is very hygroscopic and it makes the image more susceptible to degradation. Glycols are not as bad as glycerol but they are also hygroscopic. I wouldn't use any of them...

 

[Ryuji]

Hmm..coulda sworn I had a reference on this somewhere but darned if I can find it. MSDS (current threads on that topic notwithstanding) shows only agua, propylene glycol and alcohol in roughly 70-20-10. How hard could that be? I guess that might depend on the alcohol, which is this little beauty: p-tert-octylphenoxy polyethoxyethyl alcohol.

PhotoFlo comes in three strengths. PF 200, 600 and 2000. They are based on Triton X-100 (aka octylphenol ethoxylate, yet another name of the same compound you mentioned) but they differ in concentration. A surfactant like this doesn't mix with water at an arbitrary ratio, so for PhotoFlo 200, there is a need for an organic solvent together with water. This is why propylene glycol is added. (Propylene glycol is not as hygroscopic as di- or triethylene glycol, which is less hygroscopyc than glycerol.)

As far as I know, PF600 and 2000 don't contain propylene glycol.

I personally don't use Triton X-100 or similar surfactant. It's an ok wetting agent but there are better ones that have less biological toxicity. I have a custom blended surfactant that doesn't bubble like PhotoFlo and lets the water go down the film surface very quickly without leaving bubble mark.

So... I use Triton X-100 or PhotoFlo to wet mops to wipe my darkroom floor, or mix windshield washer fluid! (Surprisingly, I could formulate a windshield washer fluid that does not freeze even in this f*cking cold Boston winter. This is probably the most useful invention I made in 2005 that people around me appreciated the most.)

 

[Charles Webb]

I have used Dawn detergent perhaps 2 drops with no noticable ill effects.
I store my negatives in a verticle file so the negs are standing on edge, I have checked several times to see if the dried emulsion had slid off the clear backing and was laying in a pile in the bottom of my file cabinet. So far it hasn't!

Charlie.......................

 

[jp80874]

Somewhat off the subject of looking for a substitute. As many here, I have been looking at my kodak purchases and looking ahead . In three years of darkroom work I am half way through a four oz. bottle of Photo-Flo 200. I just purchased a $6.99 16 oz bottle at B&H, the smallest size now available there. At age 66 I fear that I may have a life time supply of Photo-Flo, possibly something my heirs can bicker about. Ah, If all of my decisions were so easily handled.

John Powers

 

[Ed Sukach]

I use Edwal LFN. Usurious price for a tiny bottle, but it works like a charm, and at the rate of one drop to a liter - or so - lasts a long time.

I had *nothing* but trouble with Kodak Photoflow - intermittent residue in the form of tiny, brown "drops" -- bulletproof after drying.

 

[Ted Harris]

Photoflow and the numerous other branded wetting agents are just that -- brand name products and that is what you are paying for.

I use a generic 'wetting agent' that I get at a professional photographic supply store in one gallon bottles. It is cheap, less than $10 for a gallon.

I had *nothing* but trouble with Kodak Photoflow - intermittent residue in the form of tiny, brown "drops" -- bulletproof after drying.[/QUOTE]

 

[Photo Engineer]

PE, can you reccommend anything that would work?

Corey

I would not recommend any detergent. They contain a scent and a colorant. The pH of most detergents is on the alkaline side.

All of this adds up to a less than optimum environment for film emulsions either from a swell, tackiness or hardness standpoint.

The best things to use are photo approved wetting agents. I have used Photo Flo for over 50 years with no problem whatsoever. But, I have also used other popular brands as well such as the wetting agent sold by the Formulary.

They all work well.

PE

 

[Gerald Koch]

For years one large pro lab used a drop or two of a clear dish detergent marketed as being hypoallergenic containing no dyes or scents.

Edwal LFN is Triton X-100 diluted with isopropyl alcohol.

 

[Photo Engineer]

The TWEEN series of surfactants comes to mind as well.

TWEEN 20 or TWEEN 80 work at the right dilution IIRC. I have not tried that for years, as I prefer buying a commercial product.

The thing I worry about in all of this is the final pH. I cannot stress that enough. You may get away with it with no problem, but if you add just a drop too much or have film sensitive to pH, this type of 'surfactant' can be a problem.

NEVER use an unapproved final rinse for color film. These films contain dyes that are pH sensitive and sensitive to the final environment in a host of other ways that preclude use of anything but a manufacturers approved final rinse.

PE

 

[Photo Engineer]

I wish to add a little note off the previous post. Here are things you can do to improve film quality if you worry about fungus and mold.

Add between 0.5 g/l and 1.0 g/l benzoic acid to the final rinse. (you can go lower - see below)

Add 3 ml / liter of 37% formalin to the final rinse.

Or, add both.

These are very good 'bug' killers that help protect films from mold, mildew, fungus and bacterial growths in damp or humid environments that can lead to film deterioration.

I know, formalin is a no-no, and I recognize that, but it is no higher in concentration above than it was in C41 or E6 stabilzers and if you accepted that, I would be remiss in not mentioning it here. I only suggest the above if you live in the tropics or in areas of high heat and / or humidity.

Please test the final dry film for tackiness before storing if you used benzoic acid. If it is too tacky to suit you, just rinse and then restabilize as noted below.

The benzoic acid does sometimes increase tackiness depending on water supply and film characteristics. If there is excessive tackiness, lower the level of benzoic acid in the final rinse until the tackiness is acceptable or vanishes. If you prefer, don't use the benzoic acid, just use the formalin. You can always rewash the film to remove the benzoic acid.

PE

 

[Ryuji]

I wish to add a little note off the previous post. Here are things you can do to improve film quality if you worry about fungus and mold.

Add between 0.5 g/l and 1.0 g/l benzoic acid to the final rinse. (you can go lower - see below)

Add 3 ml / liter of 37% formalin to the final rinse.

Or, add both.

Formaldehyde will be bound to gelatin molecule and any remainder will evaporate. Therefore, it is ineffective as a biocide in dried film.

Benzoic acid is ineffective unless the pH is very acidic. So are most other biocides used as food preservatives.

Besides the agents mentioned above are unsuitable, I wouldn't endorse the idea of adding a biocide to dry film coating in exchange for good humidity control. Even if the fungi and bacteria can be suppressed by a suitable agent (such as nonchlorinated alkyl isothiazolinone agents), the silver image is a lot more susceptible to oxidative attack and fading if humidity is high. That is a false sense of security.

 

[Ryuji]

I would not recommend any detergent. They contain a scent and a colorant. The pH of most detergents is on the alkaline side.

Dishwashing rinsing agent such as Jet Dry mentioned above are diluted pure surfactant with little additives. They contain no detergent and the pH is pretty unbuffered.

Dishwashing detergent is a different story. They are generally a blend of several anionic surfactants (sulfonates, mostly) and other agents expected in detergents. I wouldn't use them as a final rinse bath for photo processing at all.

For film gelatin, silver image, and cellulose triacetate base, neutral to slightly alkaline environment are preferrable to acidic environment. The film base is susceptible to acid hydrolysis in acidic condition and/or high humidity condition.

 

[Photo Engineer]

Formaldehyde will be bound to gelatin molecule and any remainder will evaporate. Therefore, it is ineffective as a biocide in dried film.

Benzoic acid is ineffective unless the pH is very acidic. So are most other biocides used as food preservatives.

Besides the agents mentioned above are unsuitable, I wouldn't endorse the idea of adding a biocide to dry film coating in exchange for good humidity control. Even if the fungi and bacteria can be suppressed by a suitable agent (such as nonchlorinated alkyl isothiazolinone agents), the silver image is a lot more susceptible to oxidative attack and fading if humidity is high. That is a false sense of security.

Im afraid that this is incorrect.

Both benzoic acid and formalin were used for years in Eastman Kodak stabilzers for their activity against fungi, mold and bacteria. This was a well known secondary purpose for formalin in stabilzers.

Benzoic acid supplies just a trace of acidity at that level and as it dries down in the coating the pH becomes slightly more acidic, but it has no buffer capacity to speak of and so will not harm the film or paper support. The optimum range for benzoic acid is pH 3.5 - 4.5, but it will protect even on the alkaline side (ever see "sodium benzoate added as a preservative" on food labels? Yes, it even works as the sodium salt on the alkaline side, it just takes a bit more.)

Both benzoic acid and formalin have the capacity to kill any spores present in the film or in the final rinse itself. The half-life of formalin in a B&W coating which has been optimally hardened already is as long as it takes for the formalin to evaporate. Packed in sleeves this can be quite long.

If the film were unhardened, then the gelatin would, as Ryuji says, suck it up rapidly, but this is not the case we deal with regularly. The film is already hardened. Therefore there are few sites left for formalin to react with.

The film is essentially sterilized by this treatment as you remove any spores and prevent any activity for some time to come.

The false sense of security is that this will protect you forever. It will not. The formalin will evaporate over time. The benzoic acid is relatively stable, but nothing lasts forever. One thing to consider is that handeling negatives introduces these biological contaminants and the paper sleeves that we often use also introduce them, so the formalin also 'protects' against this sort of contamination.

In high humidity, if the silver is toned or otherwise made archival, the gelatin is the thing that is attacked, and if you lose the gelatin, having a perfectly toned archival image is useless when you see the ugly traces of mold or fungus in the gelatin. By then it may be too late.

So, I offered a helpful hand from my bag of tricks, and now, above, I offer further information to you to explain in more detail.

There are many ways to approach this problem. I don't wish to rule out any of them, as long as they can be proven effective and not harmful to your film. I'm only commenting on the ones I have concrete information on.

PE

 

[Ryuji]

Im afraid that this is incorrect.

Both benzoic acid and formalin were used for years in Eastman Kodak stabilzers for their activity against fungi, mold and bacteria. This was a well known secondary purpose for formalin in stabilzers.

Benzoic acid supplies just a trace of acidity at that level and as it dries down in the coating the pH becomes slightly more acidic, but it has no buffer capacity to speak of and so will not harm the film or paper support. The optimum range for benzoic acid is pH 3.5 - 4.5, but it will protect even on the alkaline side (ever see "sodium benzoate added as a preservative" on food labels? Yes, it even works as the sodium salt on the alkaline side, it just takes a bit more.)

I'm not surprised by your usual dose of nonsense here, but here it goes...

Kodak and others used formaldehyde as a dye stabilizer in the final rinse bath for color materials. Formaldehyde is volatile and does not stay on film once dried without reacting with a larger molecule such as dye or gelatin. Today, formaldehyde is largely eliminated from the final rinse for color material, for occupational health reasons. This is especially true now because Konica came up with a safer dye stabilizer, and modern color dye couplers form more stable dyes to begin with. Old color films like Kodak VPS (Vericolor III) or PMC 400 would still need some sort of dye stabilizer.

Benzoic acid is not very soluble in water, but sodium benzoate is. This is why sodium salt is mostly used as food additive. But the food in which benzoate is used is very acidic, such as soda drinks, fruit juices, pickles, sauerkraut, etc. The undissociated form of benzoic acid is the active specie as a bactericide, and anyone familiar in organic chemistry can tell you what the pKa of a carboxyl group attached to a benzene ring is. Above pH of about 4, the benzoic acid loses bactericide efficacy rapidly. You'd need 10x more of this stuff every time you go up the pH unit by 1.0. This is unacceptable and therefore benzoic acid is not used as food preservative unless the food is very acidic.

Even so, benzoic acid is often used in combination with alkylparabens and/or sorbic acid. This is because benzoic acid is most acitive against bacteria and yeasts, and it is not very effective against fungi and molds. Parabens are more active against molds and least active against gram negative bacteria. So a combination of the two would cover the entire spectrum. Parabens are also effective in acidic or neutral pH. Parabens are also more common in less watery food that is more susceptible to fungi and molds, foods that are less acidic, and food that undergoes high temperature cooking, such as baked goods, beer, olives, jams, syrups, etc., in addition to the foods listed for benzoate.

 

[Ryuji]

In high humidity, if the silver is toned or otherwise made archival, the gelatin is the thing that is attacked, and if you lose the gelatin, having a perfectly toned archival image is useless when you see the ugly traces of mold or fungus in the gelatin. By then it may be too late.

This is also a good example of misconception toward good conservation practice. Unless 100% of the silver image is converted to silver sulfide, image is to some extent susceptible to fading by oxidative attacks, which is accelerated by high humidity condition. 100% conversion is possible but not aimed in practice. Either way, good humidity control is one of the most fundamental requirement for good keeping condition, and no amount of bactericides and bacteriostats can substitute for this. If they could, museum conservators would not spend a lot of money to build humidity controlled and refrigerated storage rooms for valuable image archive.

 

[Photo Engineer]

First and foremost, gelatin is attacked by 'bugs'. We all know this, and we know it is hastened by heat and humidity! Formalin and benzoic acid kill bugs. The fact that they were both used in color films and papers for this purpose does not negate their usefulness in B&W materials.

Before I go to my second point, I would like to stress that Ryuji orignally said that the gelatin and the formalin reacted, then in the second set of posts he said it evaporates unless it reacts with gelatin or couplers (he said dye, but it really reacts with the couplers, but I'll give him that as a typo). Actually, much more than that takes place as you will see below.....

Secondly, in materials treated with formalin that are already hardened, formalin stays behind in three forms. These are, formalin trapped within the gelatin matrix, and formalin singly bound to gelatin, but not crosslinked. In addition, a small amount of formalin does crosslink with gelatin if two active strands of gelatin are close enough for the formalin to react with. Some, of course, evaporates and some in due course kills bugs on or in the gelatin.

You see, when a gelatin is hardened, fewer sites for cross linking are left behind so formalin reacts with one strand of gelatin rather than cross linking to two strands. The singly linked formalin is easily split off and releases with time giving a small but real presence of formaldehyde in the coating. So, over time you have the free formalin which kills the initial bugs present in the process solutions (if any), those that land on the film during drying and storage (if any) and those introduced by handling (if any). (This slow release of formalin can be measured and takes place with any material that contains formalin including clothing, finished wood and leather. The slow release of formalin in the household is what can cause problems with color films as the formalin can infiltrate the film container and react with the couplers.)

During storage, any formalin trapped in the film matrix comes out gradually and sterilizes the surrounding envelope or film holder, while over time, the singly bound formalin-gel material can slowly reverse itself and release formalin. This reversal is caused by heat and humidity, the perfect conditions for 'bug' growth and what we are trying to prevent here.

This has been proven by experiment as well as the practical observation of low levels of formalin in the household environment.

Selenium toning, sulfur toning, etc etc can help preserve the silver image, but the gelatin matrix is also subject to decay. What I have offered here is a known method of preserving the gelatin. I recognize that formalin and benzoic acid are not perfect soltuions but as I said in my last post they offer a degree of protection over none at all. In fact, the growing concern over formalin and other biocides being used everywhere is probably why this method of preservation has not persisted nor been widely adopted.

There are down sides. I mentioned above that the benzoic acid can increase the tackiness of the film or paper surface. I should mention that the slight increase in hardness due to use of formalin can cause brittleness in some films. These would be films with low levels of hardener to start with (soft films) in which formalin can then take a larger role in after-hardening the film. This does not include soft films with unhardenable polymers with which formalin cannot usually react.

What we see here in this series of posts is the conflict between theory and practice. I really have no disagreement with the theory behind what Ryuji has said, it is in the actual practice that we learn that the real world throws things at us in surprising ways. This is either one of the two "S" events we used to discuss at patent meetings a lot. They are "Synergy" and "Serendipity". Both lead to patents or novel approaches to things that you cannot find if you go 'by the book'. After you discover something new using either of these "S" events or both, you can usually go back to the books and explain it. If you had stuck to doing things by the book, you would never even have discovered it.

The bottom line is that the old C41 or C-22 stabilizer with formalin and photo flo are very good as a final rinse for preserving color or B&W film, particularly in high heat and humidity, if 'bugs' are eating your gelatin.

PE