Washing between dev/stop and fixer

mesh · Jan 3, 2011

Do most people run water in the tank between dev, stop and fixer? I never have, and it hasn't been a problem (although I am still a beginner and don't have a reference) but I'd imagine it would be a good idea... there must be some contamination when reusing stop bath and fixer? Thanks.

Ian Grant · Jan 3, 2011

There's no need to wash, if you do then you can leave out the stop bath entirely with films Stop bath is used a strength that allows quite a reasonable throughput and commercial fixers are well buffered against carry over.

Having said that a stop bath or water rinse needs to be good enough to prevent developer carry over into a fixer to give it a better capacity & working life.

Ian

Steve Smith · Jan 3, 2011

I only use a water rinse between the develop and fix stages and if it is the last time the fix is being used before it is discarded then I may go straight from develop to fix without a rinse. I don't know if there is any real reason not to do this but I have never seen any problem with it.

With prints though, a stop bath is essential as the developer will carry through to the fix even with a tray of water in between.

Steve.

mesh · Jan 3, 2011

Thanks for the info. So the stop bath is kind of a wash anyway and it can't really contaminate the fixer? I think I get it now ;-)

Steve Smith · Jan 3, 2011

The stop bath should wash away the majority of the developer which is usually alkaline. A stop bath is normally acid and will neutralise the developer i.e. stop it from developing.

Fix is also generally acidic so the stop bath will not have too much effect on its action.

Alkaline fix does exist though and there is usually an alkaline stop to go with it. Again, just water can be used with film but acidic stop should not be used with alkaline fix.

Some info here: Dead Link Removed

Steve.

pentaxuser · Jan 3, 2011

The benefit of the stop is that it stops development instantly whereas with water there is presumably a short carry-over time as the first rinse is in effect an extremely dilute developer. However when I swopped from using stop bath to water I can't say I noticed a difference. Once the dev is drained and the tank filled with water the percentage of dev left in relation to the water must be very small and affect the further development only very marginally. By the time of the second water rinse and dump the residual dev percentage must be so small as to be almost non existent.

pentaxuser

Worker 11811 · Jan 3, 2011

Here's what I do. Take it for what it's worth:

I do not rinse between developer and stop bath because the stop bath is supposed to stop development immediately.
Water works but, as others have said, water only dilutes developer not counteract its action. Sometimes I use water in place of stop but I don't do both. That would be essentially redundant. Wouldn't it?

I do rinse between stop and fixer. I like to reuse fixer as much as possible. Rinsing between stop and fix helps prevent carryover of any residual chemicals.

If I am developing a few batches in one session, I'll save fixer and use it again. If I am only developing one batch I'll dump it. Dumping it prevents contamination. I don't see any reason to save stop bath long-term. The stuff is cheap.

mesh · Jan 3, 2011

Thanks for the info - much appreciated.

RalphLambrecht · Jan 3, 2011

I don't disagree with what has been said but like to add one thing:

Rinsing in water is satisfactory with weakly alkaline, slow-acting developers, but uneven image formation may result with rapid-acting developers. An acid stop bath neutralizes the alkali quickly, thus inactivating the developing action more evenly.

hpulley · Jan 3, 2011

Edit: I don't wash between dev, stop or fixer. I only wash after the fixer (I don't do a pre-soak either).

I always use (and re-use) indicator stop bath for film and paper though I use separate solutions for each purpose. I use it until it indicates via color change that it is done, then I dump it.

I reuse fixer as well but I test my fixer before I use it, before every roll and if the clearing time is slow, I dump it (yes, I should really get a silver magnet). I once used fixer that I knew was slow and I had to refix and rewash the roll as there were problems so now I know it is not worth it, test before and dump it if it is bad.

pentaxuser · Jan 3, 2011

RalphLambrecht said:
I don't disagree with what has been said but like to add one thing:

Rinsing in water is satisfactory with weakly alkaline, slow-acting developers, but uneven image formation may result with rapid-acting developers. .

Ralph Which developers are the weakly alkaline slow acting ones? I have used ID11, Rodinal, Perceptol, DDX and finally I am now using Xtol. Would all of these qualify? I think I had stopped using acid stop after ID11 and Rodinal and if some of them don't qualify under your definition then it may be that I am getting uneven image formation without realising it or should it be so obvious that I could not mistake it if it is there?

The films all look OK but I do not want to risk any potential problems either. Thanks

pentaxuser

brian steinberger · Jan 3, 2011

There is no reason to use a water wash anywhere in there, though I do use a water wash for a few minutes after the fix, before the hypo-clearing agent. Also, I would never recommend re-using an indicator stop bath until it changes color. By then its already been ineffective for a while. What I do is use my fixer until I have used it to half the recommended capacity. For Ilford Hypam this is 24 rolls per liter. I mix 2 liters at a time, so I use my fixer for 24 rolls of film (marked on the bottle on masking tape), then dump it and the stop bath and mix both new. I have never had stop bath change color before the fixer needs replaced.

hpulley · Jan 3, 2011

I don't wait until the indicator stop actually goes purple (Ilford), as soon as the yellow fades noticably I dump it.

Ian Grant · Jan 4, 2011

pentaxuser said:
Ralph Which developers are the weakly alkaline slow acting ones? I have used ID11, Rodinal, Perceptol, DDX and finally I am now using Xtol. Would all of these qualify? I think I had stopped using acid stop after ID11 and Rodinal and if some of them don't qualify under your definition then it may be that I am getting uneven image formation without realising it or should it be so obvious that I could not mistake it if it is there?

The films all look OK but I do not want to risk any potential problems either. Thanks

pentaxuser

Of all those Rodinal has the highest pH by a long way because it contains free KOH (Potassium Hydroxide).

However if there's sufficient water used to wash/rinse between Dev & Fix there's no issues.

Stop-bath has a greater advantage in a Jobo or similar rotary system as a much smaller volume can be used, but with inversion processing the volumes are much larger so water alone works just as well.

Ian

pentaxuser · Jan 4, 2011

Ian Grant said:
Of all those Rodinal has the highest pH by a long way because it contains free KOH (Potassium Hydroxide).

However if there's sufficient water used to wash/rinse between Dev & Fix there's no issues.

Stop-bath has a greater advantage in a Jobo or similar rotary system as a much smaller volume can be used, but with inversion processing the volumes are much larger so water alone works just as well.

Ian

Thanks Ian. Before seeing your post I decided to check the PH of the devs I had mentioned and it seems that Xtol DDX and Perceptol all qualify as weakly alkaline with PH's of between 7.7 and 8.5 whereas as you have said Rodinal is very alkaline.

My current dev is Xtol at about a PH of 8.2 so it looks as if all but Rodinal would qualify as weakly alkaline. Whether they do under Ralph's definition of weakly alkaline needs Ralph to comment but it looks as if my water rinses with Xtol and probably the others mentioned except Rodinal will not create the dangers that he mentions.

pentaxuser

pentaxuser · Jan 4, 2011

PS I never use less than 4 changes of water so 1L(4 x 250mls) instead of stop bath if its 35mm and 2L ( 4x 500mls) if its 120. Water is very cheap

pentaxuser

Washing between dev/stop and fixer

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