Author Topic: How long can I keep a developer  (Read 203 times)

JJChan

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How long can I keep a developer
« on: May 14, 2020, 16:38:48 »
Our local shop still has plenty of D76 powder.
I'm still new to developing film learnt from YouTube and stuff on the net only so probably doing things poorly.

Can I make a solution and keep it stored for a while or does it go off? Is it better to stick with concentrated solution (eg Ilford DDx) and mix amounts when I need it?
I'm probably developing a couple of rolls a month at the most.

TIA

JJ

Ann

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Re: How long can I keep a developer
« Reply #1 on: May 14, 2020, 17:43:27 »
I always preferred to make fresh solutions if I wasn't going to process for a while — except in the case of those solutions which are designed to be re-generated (such as the Bleach in colour film processing).

If you decide to keep and replenish for each batch, keep a record of the amount of film which has been processed and make sure that your storage bottles are filled to the rim and sealed tightly. Glass marbles added to the bottle can be useful in that case!

pluton

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Re: How long can I keep a developer
« Reply #2 on: May 14, 2020, 17:48:55 »
Exposure to/contact with air, and to a lesser extent light, is the enemy.  The dry powder in the original factory packaging should last longer than mixed liquid---assuming that however each is stored, air space in the container is absolutely minimized.
One strategy with liquids is to make the large amount (typically 1 gallon, ≈4 liters) per the directions, but instead of storing it in a single large bottle, store it is smaller containers that hold enough for one developing session, thereby avoiding the air space that occurs when the volume of developer in a large container is drawn down over time.
Concentrated liquids suffer the from same vulnerability to air exposure as dilute liquids. Dark glass is considered better than plastic. Store in the dark in any case. 
Keith B., Santa Monica, CA, USA

JJChan

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Re: How long can I keep a developer
« Reply #3 on: May 15, 2020, 00:27:51 »
Thank you Ann and Keith - will take these all onboard

Jacques

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Re: How long can I keep a developer
« Reply #4 on: May 15, 2020, 11:07:31 »
I used to use a series of concertina bottles, once the required solutions were removed press gently on the top of the open bottle until the remaining liquid is near the top and then fix the top on thereby minimising the air in the bottle. When processing B&W I always looked for the higher dilution option as in 1 part dev 3 parts water then discard the solution once processing is complete, it takes a little longer processing time but each film will be processed in the same strength ? Solution without having to make notes of how many films have been processed with the stock solution and working out if any adjustments to processing time are needed.
A.Jacks