Ilford recommends a water-saving washing procedure which, if it is adequate, saves a lot of water and allows using water from a bottle at room temperature rather than from the tap. The procedure requires using a non-hardening fixer. After fixing, the tank is filled with water and inverted five times, drained and refilled and inverted 10 times, and finally drained and refilled and inverted 20 times. That's it.

Ilford says that "this method of washing is faster, uses less water yet still gives negatives of archival permanence." If found an article by Rolf Suessbrich testing this procedure, and pretty much confirming it. Suessbrich stresses reducing water takeover from each of the three washing steps to a minimum by washing the tank, and even drying it.

This method seems great, but I am left wondering about the archival quality of the negatives. Does anyone have experience with this method? Is it enough to wash film this way?

-- Raja A. Adal (d60w0635@ip.media.kyoto-u.ac.jp), February 13, 2000

Answers

Hi, when I started two years ago (again) to process my own B&W I adopted the Ilford method - slightly amended (always use fresh water):

1st wash: 10 times inversion 2nd wash: 20 times 3rd wash: 30 times

Just a bit extra time - I'm still working with those negs and can't see any problems.

Of course, can't predict what they'll look in 20-30 years from now. But consider: most negs from 50 years ago were not "archivally" washed and look at them now - most of them pristine as ever .....

Good Luck!

-- Klaus Werner (kwerner@electronicsweekly.net), February 14, 2000.

You are omitting an important point: Before the washing cycle starts, you have to rinse the tank and the film to remove any fixer still clinging to it.

Well, it may not be enough to call it archival, but I have been using this method without bothering to dry my tank and film between the individual steps without becoming aware of any problem with my negatives for the last 10 years. My only deviation from this method is that after the 20 inversions, I bath the film for a further few minutes in demineralised water with a wetting agent, because at my place, the water is very hard.

There has been a test of the method in a German photo magazine around the time I started using it. This test confirmed that the value of residual hypo in the wash water was the same value as that measured for the water before washing. So the conclusion was that the method should be OK.

Furthermore, consider that the effect of washing is exponential. If one wash leaves 10% of the hypo that is there in the beginning, and the next step does the same, you are at 1%. A further step will take you to 0,1% asf. It is certainly a good idea not to leave the tank half full between the steps, but to dry it is certainly overdoing it.

The exponential decrease means that using the same quantity of water, the effect will be greatest when you wash as often as possible with the quantity of water used for each wash as small as possible. I remember having read an article to that effect, with a detailed mathematical derivation, in an applied chemistry journal some 15 years ago. The authors impressively showed that the effect is very different when you use one litre of washing solvent all for one wash, two washes at 500 ml, three washes at 333 ml ...

The Ilford method takes into account that the process of wahsing the hypo out of the film is a diffusion-based process, i.e. it will be the slower the smaller the concentration gradient, or the less hypo is left in the emulsion. To compensate this, each consecutive step takes longer to reach the equilibrium where leaving the film in the water for longer will not make any significant difference any more. Note that the increase in the number of inversions suggested by Ilford is exponential, too.

So if you still have doubt about the method, just add a further step with 40 inversions, and you will surely be fine (except maybe a sore arm).

As I see it, you are much more likely to contaminate your film with your fingers after having washed it it unless you wear gloves when handling the fixer and discard them when handling the film.

-- Thomas Wollstein (thomas_wollstein@web.de), February 14, 2000.

So it's homeopathic (sort of)! This has answered an important question for me. Thanks for asking it and to all who responded with such good documentation... t

-- tom meyer (twm@mindspring.com), March 05, 2000.

There's a problem in testing easily for the 'archivality' of any washing of negatives and so I always use a 'belt and braces' method, that is, I overdo things if anything. A critical thing of course is the wash water temperature, so from my domestic supply I raise a large container of filtered water to the film processing temp. - 20 deg.C. From that reservoir I nearly fill the dev. tank after the fixer has been poured out, and invert/roll/shake it for about a minute. Drain thoroughly. Next Kodak Hypo Clearing Agent is used - continuous agitation for 2 to 3 mins - thorough drainage again. Then I go into the Ilford sequence, using of course the water at the prepared temperature. Occasionally and probably for no good reason other than to satisfy myself that I've done all I can, I'll lower the temperature of my reservoir of water progressively to that of the mains water coming into the house. This I do by no more than 5 deg.C. at a time and at each lowering I accustom the films in the tank to the new lower temperature. Finally the tank is connected to the cold tap and filtered water is run through for say 20 mins. I must say I'm now tending to do this last thing less and less. I also understand it's important not to be using a hardener in the fixer as that encourages the emulsion to hang onto the thiosulphate.

-- Trevor Littlewood (t.j.littlewood@btinternet.com), March 25, 2000.