Roger Hicks on Film Washing

[dobro]

In another thread, Roger said:

My own wash sequence:

Tap water, within 5 degrees F of fixer temp:5 inversions. Dump & replace, worrying less about temperature: 10 inversions. Dump & replace: 20 inversions (Ilford sequence). Then distilled/de-ionized water, 20 inversions (removes tap water minerals -- but tap water washes fixer out better than distilled water). Final rinse: 30 sec. minimal agitation, in distilled/de-ionized water with wetting agent 1+400 or so. The last can be re-used sequentially for all the films in one processing batch.

I had not heard that tap water was more effective than distilled for washing out fixer - why is that? I developed my first roll in many years this past week and used the "Ilford sequence" but did it all with distilled water. I think I'll use Roger's method next time to save a few more cents per roll!

 

[imokruok]

I had not heard that tap water was more effective than distilled for washing out fixer - why is that?

I would assume because tap water contains a mix of different minerals which may be more effective in binding with the fixer and washing it off the surface of the film.

 

[Freakscene]

I would assume because tap water contains a mix of different minerals which may be more effective in binding with the fixer and washing it off the surface of the film.

Exactly. Seawater is a very fast wash, in terms of removing thiosulfate, but you then need to wash the seawater minerals out of the film. I washed a lot of film in seawater with just a rinse in distilled water at the end, followed by a proper wash a month or two later, when I was living in places where freshwater was very scarce. Those negs look fine ~15 years on.

Marty

 

[sevo]

Fixers are usually acidic to stop the developer action and prevent fogging. Some of the silver complexes created in the fixer dissolve very slowly in a acidic environment, so that some care has to be taken that the pH level of the emulsion layer increases to sane values within the wash, or those silver salts that already failed to dissolve into the fixer will remain in the film.

Distilled water has no buffer and will immediately tip towards the sour side from the fixer traces, making it inefficient in that regard. Tap water is quite well buffered by the salts (mostly calcium carbonate) in it, so that it can absorb a fair bit of fixer traces before its pH tips over and renders it inefficient - with tap water, silver elimination will start out much faster and at a larger scale.

 

[Roger Hicks]

I would assume because tap water contains a mix of different minerals which may be more effective in binding with the fixer and washing it off the surface of the film.

From what I understand -- and Marty will know far more than I -- the minerals in the tap water displace the fixer and fixer products in the gelatine and are themselves more easily washed out than fixer and fixer products.

The phenomenon is well documented in the literature but I don't remember trying to follow the chemistry of it, because most phototographic chemistry tends to be fearsomely complicated with sequences of reactions, transitory compounds, and a certain amount of "It is believed that..." even in the original research papers.

EDIT: I see that Sevo understands more than I, because he has bothered to read the chemistry, which is less complicated than I thought (either that or he's explained it particularly clearly and well). Thanks.

Cheers,

R.

 

[Jaans]

In another thread, Roger said:



I had not heard that tap water was more effective than distilled for washing out fixer - why is that? I developed my first roll in many years this past week and used the "Ilford sequence" but did it all with distilled water. I think I'll use Roger's method next time to save a few more cents per roll!

I have to say that I used to waste money on using distilled water for all of my wash cycles until I also read that advice from Roger. It has ended up saving me so much time, effort and money as I don't have to lug around as much distilled water in the 5 litre containers.

So, I wanted to say thanks also to Roger for your consistantly sound advice. Your website is also a treat and for anyone just starting out or even advanced photographers, it is an excellent starting point as well as providing more intricate information. Roger's explanation of exposure is second to none and I'm sure Mr Adams is turning in his grave as I speak^^

Cheers,
Jaans

 

[gilpen123]

My washing are done using purified water (mineral) because our tap water in my place is deep well (hard) and leaves a lot of residue. <$0.50/5 gallon container very cheap actually.

 

[Freakscene]

Neither distilled or tapwater have significant buffering capacity. Calcium carbonate is a poor buffer although it is mildly alkaline. If your water is rich in it you will get drying marks and the stability of the silver image may be undermined.

Roger is right that it's complicated, but it's worse than normal chemistry - it's physico-chemical, with changes in the adsorbancy, covalent bonding between ions and the gelatin and replacement of fixation by-products with ions that are more easily washed out later. There is a good explanation of fixation here: http://www.cheresources.com/photochem.shtml none of these reactions occur to completion and so the "adsorption complex" must be removed, as well as the "desorbed" components.

Marty

 

[sevo]

phototographic chemistry tends to be fearsomely complicated with sequences of reactions, transitory compounds, and a certain amount of "It is believed that..." even in the original research papers.

Right, photo chemistry is right on the fence between physical and chemical activity - there is no uniform and simple solution for these kinds of problems. Which makes it a bit scary that the big film producers are falling apart, closing labs and cutting their R&D and QC staff - there is a lot of expertise involved which was empirical and pragmatic, and will be lost once there only are textbooks left...

 

[dobro]

Well alright then! I'm using Photographer's Formulary TF5, which is an alkaline fixer to begin with. I don't suppose that would change anything...

I've got a bit of reading to do....thanks all!

 

[sepiareverb]

And don't forget: a residual fixer test will confirm that enough washing has been done.

Also available from the Formulary in an easy to mix kit:

 

[Roger Hicks]

Right, photo chemistry is right on the fence between physical and chemical activity - there is no uniform and simple solution for these kinds of problems. Which makes it a bit scary that the big film producers are falling apart, closing labs and cutting their R&D and QC staff - there is a lot of expertise involved which was empirical and pragmatic, and will be lost once there only are textbooks left...[/QUOTE]

Exactly, which is why I got a bit annoyed with someone a while back who suggested that Kodak, Ilford etc. should move production to China.

Quite apart from the size, cost and complexity of a coating line, all of which were clearly far greater than they imagined, there's the question of a skills base. There are probably only a few dozen photographic emulsion chemists left in the world. The really good ones are likely to be middle aged or older, and disinclined to go to China; Chinese emulsion chemists are even thinner on the ground than in the UK and USA; and training an entire workforce of people who don't really understand what they're doing, en masse, from scratch, doesn't bear thinking about.

The whole quesion of skills bases is VERY worrying. Even accountancy is only partially a transferable skill (hospital accounts/priorities are different from manufacturing, are different from retail, are different from military...) but managers and accountants are sometimes (not always, thank God) inclined to think that they can tell everyone how to do everything. Of course the same is true of salesman which is why I thought Carl Kohrt would have been a much better bet to head Kodak than Carp or Fisher.

Cheers,

R.

 

[sevo]

Well alright then! I'm using Photographer's Formulary TF5, which is an alkaline fixer to begin with. I don't suppose that would change anything...

Alkaline fixers do stabilize the thiosulfate better - on the other hand they have dichroic fogging issues, often of considerable severity, and tend to be slow acting. As far as washing is concerned, they are a mixed bag - TF5 has a reputation for clearing very thoroughly end efficiently, but there also are some other alkaline fixers that are pretty hard to clear.

 

[Roger Hicks]

And don't forget: a residual fixer test will confirm that enough washing has been done.

Also available from the Formulary in an easy to mix kit:

Not necessarily. Once you have your washing routine weighed off, there should be no need to keep re-testing. I used to, but then realized that as I had changed no variables, I was wasting time and chemicals.

Also, most recommended washing routines will wash to ANSI standards.

Cheers,

R.

 

[calebk]

The Ilford sequence (which I found on the Ilford Rapid Fixer data sheet, as well as Roger's website) says to fill your dev tank with water +/- 5ºC from dev temp, do five inversions and pour the water away. Repeat with ten, then twenty inversions, pouring after each set of inversions, and by right, your film should be washed to ANSI standards.

 

[Gerry M]

I have been using an upright cylindrical washer (35 & 120), plumbed from a tap and routed thru a filter first. Is this OK? Yes/No
Gerry

 

[jmcd]

dobro wrote: Well alright then! I'm using Photographer's Formulary TF5, which is an alkaline fixer to begin with.

I used TF-5 recently with film, mixed a half gallon, and within a few rolls the film's clearing time more than doubled, and the fixer turned color. I was told by one of the people who worked on the development of this fixer that it has pink dyes and high iodide content. I am using Ilford film.

I switched back to TF-4, and I can safely fix at least 45-50 rolls of film (24 ct) before my clearing time doubles.

I still use the TF-5 for fixing paper, where it does fine.

 

[dobro]

Hmm, I'll have to watch my clearing times...FWIW, I'm using Legacy Pro 100 - a/k/a Acros. Thanks!

Lee

 

[sevo]

The Ilford sequence and other water saving sequences work. However they require fixing precisely to the recommended time. Old practice often had it that only the development was done very accurately while fixer, stop and wash timing, temperature and concentrations were sloppily handled. In modern wash regimes you'll also have to stop and fix exactly to specifications, or the wash may fail to reach archival grade!

 

[wgerrard]

Don't the chemicals in tap water vary significantly from place to place and time to time? At least, that's what my taste buds tell me.