What happens if I under-wash film slightly?

Perhaps I'm being paranoid here. I noticed, as I expect many have, that the Film Developing Cookbook describes the Ilford wash method (5 inversions, change, 10 inversions, change, 20 inversions, change), but specifies 5 minutes of stand time between cycles and emphasises that descriptions published "elsewhere" without the 5 minutes are incorrect.

I've washed a bunch of rolls per Ilford recommendations, without the 5-minute wait in between. I'm trying to decide whether I should worry about this.

In general, I don't quite understand what happens if film isn't quite adequately washed. I guess the residual fixer can attack the image silver, right? Are the results obvious, so that if I look back at an old roll and say "doesn't look damaged", I can assume it's OK? Or is there some long-term issue, where a roll of film that seems fine now might turn out to be damaged on the off chance that my great-grandchildren ever want to look at it?

Thanks.

-NT

Yes, it's a long term issue. It depends on how much fixer is left in the print/roll. More fix, faster change.

If you are really feeling paranoid about it, you can rewash the negs. It wont hurt them.

I was under the impression that there is still some controversy over whether the 5 min wait between each of the 5/10/20 inversions and dumps is required. I don't recall seeing any requirement for 5 mins between each cycle in the current Ilford info. I don't want to contradict the emminent publication you mention but it seems to me that if the 5 mins waits between dumps were crucial then Ilford would make sure it was included in its literature. After all it is hardly in its interest to have users discover problems with negs even many years from now. If you do a search you'll eventually find the thread. I don't know its title.

I think I recall a number of eminent photographers in the thread who didn't bother with the 5 mins. Les McLean I think doesn't follow the 5 mins wait but does go for 5/10/20/10/5 - just for luck so to speak. In other words he does extend the cycles beyond the Ilford practice but was good enough to say this was a form of insurance rather than knowledge that it was essential. He is certainly an advocate of the Ilford practice being sufficient as opposed to the need for continuous stream washing. I think he said that he had seen no deterioration in negs that had been washed in this way and were then over 30 years old.

On the other hand if time isn't of the essence in your processing then you could argue that, as insurance and for peace of mind, the 5 min waits are worthwhile.

pentaxuser

You can also test for residual fixer. It's wise to do it even if you think your procedures are okay, because it will give you a definitive answer.

A guy I knew took his students film and said "Com'on, we have some place to be!" and took the guys film and threw it in the toilet and flushed it once. Then he looks at him and said, "oh, you want this archival" and flushed it again.

He's been printing off those negatives for 20 years now.

(I would just wash the film again)

I am glad that the 5min stand got brought up here. The inversions get a some thing flowing but the time to just soak is very important.

Another hobby of mine is fountain pens. The ink often dries in the nibs. I have washed them every way you can think of; flowing water, agitation in water, drawing water in and out with the fill tube. Anything I do that does not look like the Illford method (fill-agitate-stand-dump{repeat several times}) will always have residual ink. I check this by wetting the nib and placing it on a tissue. If I include several stand periods it will come out clean without them i will see ink.

I use this for an analogy to washing film. Before I discovered the effectiveness on pen nibs I washed negatives more traditionally, some nearing 40 years, and none show any signs of deterioration. Periods of just being in the still water, for what ever the mechanism, aid in the wash be it pen nibs or film. But as the Ilford uses less water and by analogy shown me to be effective it is my chosen method for wash.

TR

Trex,

I echo your experience with the fountain pens as I discovered the same thing.

If the same holds true for film, then if 5 minutes is good, then 10 or 15 minutes between inversions should be better. That's certainly true for fountain pens. Maybe those longer soaking times are not necessary for film, however.

Hi ntenny.

25 or so years of using the Ilford method and no deterioration in my negatives. Just my personal experience for what its worth...

John.

trexx said:

Another hobby of mine is fountain pens. The ink often dries in the nibs. I have washed them every way you can think of; flowing water, agitation in water, drawing water in and out with the fill tube. Anything I do that does not look like the Illford method (fill-agitate-stand-dump{repeat several times}) will always have residual ink.

TR

Click to expand...

There is a big difference between dried ink, and wet fixer. Part of the problem with anything dry is you have to wait for it to go back into a solution for the rinse to work. Fixer is already in liquid form so there is no need to soak to bring it back into solution.

Having said that I use the Ilford method and then let the film sit in distilled water for no inversions for 20-30 minutes (or more if I am lazy). The good folks at Efke printed that once and it really helps discharge static and dust.

Film washing is a combination of displacement and diffusion. Initially, the wash water quickly displaces excess fixer by simply washing it off the surface. However, some thiosulfate has been absorbed by the film emulsion, and it must diffuse into the surrounding wash water first, before it can be washed away. As long as there is a difference in thiosulfate concentration between the film emulsion and the wash water, thiosulfate will diffuse from the film into the water. This gradually reduces the thiosulfate concentration in the film and increases it in the wash water. Diffusion continues until both are of the same concentration and an equilibrium is reached, at which point, no further diffusion takes place. Replacing the saturated wash water with fresh water repeats the process, and a new equilibrium at a lower thiosulfate level is obtained. The process is continued until the residual thiosulfate level is at or below the archival limit.

During cascade washing, the saturated wash water is entirely replaced with fresh water each time the equilibrium is reached. This repeats the process of diffusion afresh. Cascade washing is continued until the residual thiosulfate level is at or below the archival limit. The time to reach the diffusion equilibrium varies with film emulsion and depends on water temperature and agitation. The number of water replacements required to reach the archival residual thiosulfate limit depend on the volume of wash water used. Nevertheless, my tests have shown that a typical roll film is easily washed to archival standards in 500 ml of water after 5-6 full exchanges, if left to diffuse for 5-6 minutes each time.

ntenny said:

Perhaps I'm being paranoid here. I noticed, as I expect many have, that the Film Developing Cookbook describes the Ilford wash method (5 inversions, change, 10 inversions, change, 20 inversions, change), but specifies 5 minutes of stand time between cycles and emphasises that descriptions published "elsewhere" without the 5 minutes are incorrect.

I've washed a bunch of rolls per Ilford recommendations, without the 5-minute wait in between. I'm trying to decide whether I should worry about this.

In general, I don't quite understand what happens if film isn't quite adequately washed. I guess the residual fixer can attack the image silver, right? Are the results obvious, so that if I look back at an old roll and say "doesn't look damaged", I can assume it's OK? Or is there some long-term issue, where a roll of film that seems fine now might turn out to be damaged on the off chance that my great-grandchildren ever want to look at it?

Thanks.

-NT

Click to expand...

RalphLambrecht said:

The time to reach the diffusion equilibrium varies with film
emulsion and depends on water temperature and agitation.

The number of water replacements required to reach the
archival residual thiosulfate limit depend on the volume
of wash water used.

Click to expand...

Not a word of the subject of the washing, the fixer. Both
the time twixt and number of water changes are influenced
by the fixer's dilution and the dissolved silver load it carries.
The more dilute the fixer and the less used, the quicker to
diffuse and the less water needed.

A typical example is rapid fix at 1:4 and 1:9; film and paper
strength. At 1:9 the fix has 1/2 the chemistry at start of
washing. Also, as used, it has a lesser amount of the
tri thio complex present; a heavy slow to move ion.

I use fixer very dilute one-shot, film and paper. To wash film
I use a relaxed Ilford sequence; in with the water, a few
inversions then and agin after 1 to 3 minutes. Same
for the 2nd and 3rd washes.

I don't know how fast my even more dilute paper fix washes
out. I don't push it; an over night soak. I have though had
clean to the HT-2 test prints with ONE soak. That ONE
soak followed a post fix hold/soak. Dan

Not to mention fixer dilution or silver load in fixer was done for good reason.

Firstly, we were talking about film, and therefore, film-strength fixer was assumed. I don't recommend the use of paper-strength fixer for film. The fundamental idea of archival fixing is to use strong fixer for a short time, not weak fixer for a long time. Admittedly, this is more important for FB paper than for RC-prints or film, but the principal is the same.
As to the silver load, I recommend to always use the two-bath fixing method for film (especially for Tmax), therefore, there is no silver load assumption either. This nicely eliminates two variables.

However, there are other variables influencing the speed and quality of the wash, which are worth mentioning. The big ones are wash-water temperature, hardness and the type of fixer, acid or alkali. Warm water washes better than cold, soft water does not wash as well as hard, and alkali fixer wash out easier than acid fixers.

Nevertheless, this is all going beyond the original question, which was about the soaking time between washing intervals.

The short answer is, that they are needed to give the fixer concentration in film and wash water enough time to reach an equilibrium. How long that needs to be, depends on the variables above and others, but 5-6 minutes is a very safe bet. Shorter times may work with some combinations. A test is recommended to verify the effectiveness of any custom setup.

dancqu said:

Not a word of the subject of the washing, the fixer. Both
the time twixt and number of water changes are influenced
by the fixer's dilution and the dissolved silver load it carries.
The more dilute the fixer and the less used, the quicker to
diffuse and the less water needed.

A typical example is rapid fix at 1:4 and 1:9; film and paper
strength. At 1:9 the fix has 1/2 the chemistry at start of
washing. Also, as used, it has a lesser amount of the
tri thio complex present; a heavy slow to move ion.

I use fixer very dilute one-shot, film and paper. To wash film
I use a relaxed Ilford sequence; in with the water, a few
inversions then and agin after 1 to 3 minutes. Same
for the 2nd and 3rd washes.

I don't know how fast my even more dilute paper fix washes
out. I don't push it; an over night soak. I have though had
clean to the HT-2 test prints with ONE soak. That ONE
soak followed a post fix hold/soak. Dan

Click to expand...

Is there a test for adequate washing?

I don't want to wash things for ages because I am not sure whether I am washing things well enough.

For me, I fix for longer than the box says I should. After that the negative is still purple or blue. I wash until the dye washes out.

But I will only discover whether that was good enough years later when it is too late. Is there some more immediate test I can perform?

Unfortunately, overfixing makes it necessary to wash even longer, so that actually makes things worse, not better.

My solution:
- use an alkaline fixer. They require relatively short wash times (about 5 minutes in slowly running water) even without the use of a hypo-clearing agent.
- wash for 15 minutes, just to be absolutely sure.

Truthfully, even my negatives from the 1980s look good (I gave a 2-minute wash, a dose of HCA and a 15-minute wash to them), but the new system is a lot less work.