Fixer contamination with Hypo Clear?? Result??

Sparky · Jul 1, 2007

Like a big smartie... I just poured about two tablespoons of hypo clear into a FULL gallon bottle of fresh fix I just mixed up -instead of into the EMPTY bottle - that I was trying to clean out!! Anyone know if the fix will still work as intended? I really can't see any reason why it wouldn't.. I mean - don't some fixers contain some sodium sulfite...? Or is it just WAY too late and I should be sleeping now??

Ian Grant · Jul 1, 2007

It's highly unlikely to make any difference at all. The fixer will still work, the hypo clear may contain sodium carbonate as well as sulphite which would reduce the pH a little.

Try it and see, why not use a two bath fixer system for prints with some fresh fix as the 2nd bath that would ensure optimum fixation.

Ian

Sparky · Jul 1, 2007

well - i don't have any backup! I already screwed up a few sheets of this shoot ANOTHER way.... and REALLY REALLY CANNOT afford to lose any more. Guess I'll have to wait a few days - so I can get some fresh fix... I'm certain it's probably FINE - but I just cannot afford a one-in-a-million reaction that will throw off the rest of my film.

DrPablo · Jul 1, 2007

Don't you have any of the hypo check drops?

Just fix a test negative -- if it clears normally then I don't think you need to worry about it.

dancqu · Jul 1, 2007

Sparky said:
I just poured about two tablespoons of hypo clear
into a FULL gallon bottle of fresh fix .... Anyone know
if the fix will still work as intended? I really can't see any
reason why it wouldn't..

What sort of hypo clear? Two tablespoons of Powder
or working strength? And the fixer?

As you see it the problem is the mixture of the two.
Used separately, no problem. So, have the fixer's usual
working characteristics been retained after the addition
of some hca? As has been suggested go ahead and test.
Very likely you'll find the fixer working an usual. Dan

Michel Hardy-Vallée · Jul 1, 2007

My book of photo chemistry secret lore tells me that hypo-clearing agents do not react chemically with the thiosulfate compounds (Haist p. 648). What will happen is just that the ions from the HCA will push away the thiosulfate ions that are adsorbed by the silver image (Haist p. 651). But it won't degrade these ions.

So it's not like the fixer has been transformed by something else by the addition of HCA. (anybody with more chemistry knowledge, please correct if I'm missing something here!).

Like others have recommended, a clip test will tell you whether your fixer is still fixing.

But frankly, fixer is cheap compared to negatives... I would just buy fresh stuff because I'm not that interested in learning more about the side-effects of extra sulfite in fixer.

Sparky · Jul 1, 2007

dancqu said:
What sort of hypo clear? Two tablespoons of Powder
or working strength? And the fixer?

As you see it the problem is the mixture of the two.
Used separately, no problem. So, have the fixer's usual
working characteristics been retained after the addition
of some hca? As has been suggested go ahead and test.
Very likely you'll find the fixer working an usual. Dan

It was raw permawash - from the bottle I poured into the stock strength fixer bottle. I'd test - but there's not really much point. i'm sure it could clear a neg... but my greater concern is long-term stability. I guess it's more worth it to me to process the negs later and then use 'proper' fixer. I'm sure it WOULD Be fine - but I guess I'd never forgive myself if something funky were to happen (spots showing up on negs later or something).

Sparky · Jul 1, 2007

mhv said:
My book of photo chemistry secret lore tells me that hypo-clearing agents do not react chemically with the thiosulfate compounds (Haist p. 648). What will happen is just that the ions from the HCA will push away the thiosulfate ions that are adsorbed by the silver image (Haist p. 651). But it won't degrade these ions.

So it's not like the fixer has been transformed by something else by the addition of HCA. (anybody with more chemistry knowledge, please correct if I'm missing something here!).

Like others have recommended, a clip test will tell you whether your fixer is still fixing.

But frankly, fixer is cheap compared to negatives... I would just buy fresh stuff because I'm not that interested in learning more about the side-effects of extra sulfite in fixer.

Yes, that's pretty much what I'd think, Michel. As mentioned above... the only question would be a stability concern. I'll just buy fresh fixer. At the time - I was in a bit of a frenetic rush to get this done - but I've given up out of fear of something happening to the film (would have been kind of hard to buy fresh fixer sunday at 4:00 in the morning!).

Michel Hardy-Vallée · Jul 2, 2007

Stability: one way to look at it is to compare with what happens when you mix your selenium toner with HCA. KRST contains large amounts of fixer (IIRC it has something to do with the solubility of selenium), so it builds up significant thiosulfate level in paper. The Ansel Adams way of mixing KRST with HCA is actually effective in reducing the amount of thiosulfate that stay in the paper base or the emulsion.

The problem, as Tim Rudman mentions in his toning book, is that HCA degrades quickly. He doesn't recommend keeping diluted HCA for longer than a single session. Selenium, on the other hand, last much longer. So once your HCA degrades, its positive effect in counterbalancing the excess thiosulfate of KRST is negated. You're back to square one, so to speak.

If I follow that logic for your case, the HCA will eventually degrade, and the fixer will stay relatively unaffected. But as was mentioned above, it might effect pH. Rapid acid fixers are less effective when pH rises, so your fixer would be a little less effective than fresh fixer.

Anyway, at this point it's a purely academic question, but hey! I'm an academic-in-training... (just not in chemistry, so don't quote me!)

Sparky · Jul 2, 2007

Michel - yes.. well, there are true aspects to what you're discussing - though I suppose it doesn't necessarily have to do with the fixer's ability to remove silver halide when actually fixing the film. Though - what's FUNNY- and what it makes me wonder about - is that, well... when you think about it - fixer really is simply another form of HCA - isn't it? We put our film in it for the purpose of removing undeveloped silver halide compounds - much as we put our film in HCA to remove fixer and it's by-products. I should really learn more about the chemistry of the fixing process - ! Seems that the old 'hypo' is just one of many many compounds that would do the same thing.

J.

Ole · Jul 2, 2007

Permawash, like HCA, consists mostly of sodium sulfite.

Fixer contains sodium- and/or ammonium thiosulfate, plus pH modifiers - and sodium sulfite as a preservative.

The fixer should be perfectly OK for use.

"Hypo" is a dangerous word. In the photographic context it means sodium thiosulfate, although that should be specified by writing "sodium hyposulfite" in full. Unfortunately the product "Hypo Clearing Agent" uses the abbreviated form in the product name, even though it doesn't contain any "hypo" at all: HCA is meant to remove "hypo". That doesn't mean that it will destroy fixer, you would need a "Hypo eliminator" to do that...

Sparky · Jul 2, 2007

actually - funny you should MENTION that Ole... since the original version of that post I'd written 'the old thio'... just to have some fun updating terminology... but I figured there might be someone coming in to correct me - not sensing my playfulness. So I changed it to 'hypo'. But I think we all understand what we mean by it...

Michel Hardy-Vallée · Jul 2, 2007

Sparky said:
Michel - yes.. well, there are true aspects to what you're discussing - though I suppose it doesn't necessarily have to do with the fixer's ability to remove silver halide when actually fixing the film. Though - what's FUNNY- and what it makes me wonder about - is that, well... when you think about it - fixer really is simply another form of HCA - isn't it? We put our film in it for the purpose of removing undeveloped silver halide compounds - much as we put our film in HCA to remove fixer and it's by-products. I should really learn more about the chemistry of the fixing process - ! Seems that the old 'hypo' is just one of many many compounds that would do the same thing.

J.

I think I read somewhere that thiosulfates themselves can displace adsorbed thiosulfates! So yes, it's tit for tat!

dancqu · Jul 3, 2007

Sparky said:
I should really learn more about the chemistry of the
fixing process! Seems that the old 'hypo' is just one of
many many compounds that would do the same thing.

Hypo, sodium thiosulfate and it's ammonium thiosulfate
variation, is the ONLY chemistry we in the darkroom use
to remove unexposed silver halides from films and papers.

Where the bromide of silver and in particular the iodide of
silver are concerned the ammonium ion has little effect. It's
the thiosulfate which joins with the silver, forming soluble
silver compounds.

Rapid ammonium fixers slow way down when they meet
with silver iodide emulsions. To some large degree a rapid
ammonium fix becomes little more than a sodium fix. S or A,
capacity is reduced when iodide is present. Silver iodide
is a most insoluble salt of silver. Dan

patrickjames · Jul 3, 2007

I have been putting Permawash in my fix for over a decade at this point. It is a great way to avoid staining of prints while toning, especially sepia toning. I mix it up exactly as you did. I know many others who do the same thing. It is sort of a non secret secret.

By the way, I am talking about prints, not film. I have never done this with film.

Patrick

Tom Hoskinson · Jul 5, 2007

Sparky said:
It was raw permawash - from the bottle I poured into the stock strength fixer bottle. I'd test - but there's not really much point. i'm sure it could clear a neg... but my greater concern is long-term stability. I guess it's more worth it to me to process the negs later and then use 'proper' fixer. I'm sure it WOULD Be fine - but I guess I'd never forgive myself if something funky were to happen (spots showing up on negs later or something).

Permawash - - thus you added some ammonium sulfite instead of sodium sulfite (the key ingredient in Kodak HCA).

Neither chemical should do anyting bad to your fixer.

However, fixer and permawash are both pretty cheap. Why not dump the fixer and start over.

Chris Breitenstein · Jul 5, 2007

Hypo Clearing Agent converts the thiosulfate in fix in to simple sulfate; therefore making it unable to remove unreduced silver. I don't think that fix is good any more. Then again a simple test could make a liar of me.

Yours;

Ole · Jul 5, 2007

Chris Breitenstein said:
Hypo Clearing Agent converts the thiosulfate in fix in to simple sulfate;

No. Hypo eliminator does that; Hypo Clearing Agent does not.

Chris Breitenstein · Jul 5, 2007

Ole said:
No. Hypo eliminator does that; Hypo Clearing Agent does not.

Oh. I was under the impression that they were all the same thing just different brand names, Ie. Hca, Permawash, orbit bath etc. If all of these washing agents don't break down the exhausted thiosulfate into something that will dissolve in water, then what do they do? I guess what im asking is how do these other products shorten the wash time?

Yours;

Tom Hoskinson · Jul 5, 2007

Chris Breitenstein said:
Oh. I was under the impression that they were all the same thing just different brand names, Ie. Hca, Permawash, orbit bath etc. If all of these washing agents don't break down the exhausted thiosulfate into something that will dissolve in water, then what do they do? I guess what im asking is how do these other products shorten the wash time?

Yours;

If used after an acid fixer, the HCA chemicals RAISE the film or paper pH and swell the emusion gelatin. They also help washing by forming byproducts of the acid fixing process that are more water soluble.

If used after an alkaline (or neutral) rapid fixing bath that contains ammonium ion, the HCA chemicals don't do anything useful. A plain water wash is all that is needed after an rapid fixing bath that contains ammonium ion. (except for toning).

Chris Breitenstein · Jul 5, 2007

Ok, thanks Tom, I think I have it now.

Yours;

dancqu · Jul 5, 2007

Tom Hoskinson said:
If used after an alkaline (or neutral) rapid fixing bath
that contains ammonium ion, the HCA chemicals don't
do anything useful.

I have to question that assertion. To say that a follow up
hca has no useful effect, IMO, is stretching it. The same goes
for a S. Thio. fix. A wash following an S. Thio. alkaline fix should
benefit to at least some degree from an hca treatment. I'm not
saying though that a hca is required following an alkaline fix.

That great protagonist of the alkaline fix Bill Troop has
never distinguished twixt the sodium or ammonium form of
thiosulfate. He specifically mentions TF-2. He has maintained
that an alkaline fix, S or A and the more alkaline the better,
needs no hca. My work, much more off than on, backs up
his assertions.

For those interested, search rec.photo.darkroom for,
ephraums 10.5 . Dan

Michel Hardy-Vallée · Jul 5, 2007

One important difference between sodium and ammonium thiosulfate, is that at the same pH, ammonium thiosulfate has a greater reducer effect on the silver image than sodium thiosulfate (Russell & Crabtree 1932). Hence the recommendation not to over-fix when using rapid fix.

That's why Haist recommends a sodium thiosulfate fixer for the "finely divided silver image" of certain papers (591). If you're using Azo, for example, I suppose you should stick to traditional fixer.

Ammonium thiosulfate is also relatively less sensitive to the buildup of iodide ions than sodium thiosulfate (K. Frank 1966). Because modern film emulsions contain a certain amount of silver iodide, you're better off with a rapid fixer, acid or alkaline (Haist, 589).

I'm curious to know if anyone has compared the look of prints fixed with either rapid or traditional fixer. My guess is that the difference is perhaps too subtle to be noticed by the casual observer, and that the recommendation not to over-fix is really just to ensure that people don't destroy their prints by letting them in the rapid fixer for an entire printing session. But I'd like to know.

__________

H.D. Russell and J. I. Crabtree, "The reducing action of fixing baths on the silver image" J. SMPE 18: 371 (1932).

K. Frank, "Some aspects of developer and fixing bath concentrates based on potassium and ammonium salts respectively," J. Phot. Sci. 14 (1): 44 (1966).

Grant Haist. Modern Photographic Processing. Volume 1. John Wiley & Sons. (1979)

Tom Hoskinson · Jul 5, 2007

mhv said:
One important difference between sodium and ammonium thiosulfate, is that at the same pH, ammonium thiosulfate has a greater reducer effect on the silver image than sodium thiosulfate (Russell & Crabtree 1932). Hence the recommendation not to over-fix when using rapid fix.

That's why Haist recommends a sodium thiosulfate fixer for the "finely divided silver image" of certain papers (591). If you're using Azo, for example, I suppose you should stick to traditional fixer.

Ammonium thiosulfate is also relatively less sensitive to the buildup of iodide ions than sodium thiosulfate (K. Frank 1966). Because modern film emulsions contain a certain amount of silver iodide, you're better off with a rapid fixer, acid or alkaline (Haist, 589).

I'm curious to know if anyone has compared the look of prints fixed with either rapid or traditional fixer. My guess is that the difference is perhaps too subtle to be noticed by the casual observer, and that the recommendation not to over-fix is really just to ensure that people don't destroy their prints by letting them in the rapid fixer for an entire printing session. But I'd like to know.

__________

H.D. Russell and J. I. Crabtree, "The reducing action of fixing baths on the silver image" J. SMPE 18: 371 (1932).

K. Frank, "Some aspects of developer and fixing bath concentrates based on potassium and ammonium salts respectively," J. Phot. Sci. 14 (1): 44 (1966).

Grant Haist. Modern Photographic Processing. Volume 1. John Wiley & Sons. (1979)

Michael, I contact print on Azo and develop most of the time in Amidol. I follow Michael A Smith's procedure for fixing Azo prints which uses an acetic acid short stop, followed by 2 (short) separate sodium thiosulfate fixing baths, followed by washing and Selenium Toning.

See: http://www.michaelandpaula.com/mp/Azo_Formulas.html

I also have fixed Azo prints in an Ammonium Thiosulfate neutral pH fixer, using care not to over fix, followed by Selenium Toning, with acceptable results.

Michel Hardy-Vallée · Jul 6, 2007

Tom Hoskinson said:
Michael, I contact print on Azo and develop most of the time in Amidol. I follow Michael A Smith's procedure for fixing Azo prints which uses an acetic acid short stop, followed by 2 (short) separate sodium thiosulfate fixing baths, followed by washing and Selenium Toning.

See: http://www.michaelandpaula.com/mp/Azo_Formulas.html

I also have fixed Azo prints in an Ammonium Thiosulfate neutral pH fixer, using care not to over fix, followed by Selenium Toning, with acceptable results.

Thanks for the note, Tom. It seems your (and their) printing technique is coherent with the literature!

Have you noticed any difference with the image depending on the fixer you use? In a bout of curiosity I was thinking about buying some Kodak Fixer for paper prints. However, I thought I read somewhere that some modern papers contain iodide (PE?), so maybe rapid fix is enough.

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