Storing chemicals

Discussion in 'Black and White' started by patrick_mason|3, Feb 8, 2010.

  1. Hi just a quick question about how to best store chemicals. I have started developing and printing my own film again recently and i am still a bit unsure on what to do with my chemicals when i'm not using them. i know i can reuse my fixer for a certain amount of time so should i just pour the used fixer into another container and reuse it until it is fatigued (if so what would be the best type of container?) or would it be better to just make up a big lot of working solution and just keep pouring the used fixer back into that? As far as developer i guess just leave it in its original bottle? Any help or suggestions on what you do would be great.
    Cheers
     
  2. I use milk clear PET bottles or better the milk dark multilayer bottles for developer, fixer, stop, toners, bleach, ecc ecc...
    I change bottles one or two time a year and I reuse same chemicals for weeks and weeks (TMAX developers only, others developer only 1 time!)
    I like using milk bottles because different colors of caps (blue, red, yellow, green, ecc) and because is simple reduce air in the bottle...
    Bye
     
  3. Just to chime in on the plastic milk container mention.
    I put my D76 mix in to one of these (gently pressing out the air) for about two months of use, after which it sprung leaks at many of the creases all at once! Leaked out all of the D76 chemical.
    Maybe it's the biodegradable time clock that kicked in and the nature of these milk containers?
    I use the clear "bottled water" ones now. I can't squeeze out the air much, but I've used a squirt of canned air as I cap it up to displace the oxygen. Seems to work OK...
     
  4. For years and years, glass bottles have been the preferred storage container for liquid photo chemicals. Glass is the most impervious thus less likely to contaminate. Following glass is polyethylene. This is a highly inert plastic. Polyethylene chemical storage bottles are thick walled thus highly robust. Most photo chemicals are subject to aerial oxidation. Developers, by definition have an affinity for oxygen. The developing agent is a derivative of benzene and when it oxidizes reverts to coal tar. This is a staining agent that turns the fluid murky and it will damage films and prints.
    To reduce the effect of aerial oxidation, marbles are added to the fluids in glass bottles to displace excess air. In open tanks, a floating lid is constructed using plastic or paraffin. Plastic bottles can be squeezed to displace air.
    The developer is suitable to breakdown upon prolonged exposure to light. To extend shelf life, brown or green bottles are preferred.
    PET is OK too however beverage bottles are usually designed for one-time use thus they are not nearly as robust as bottles specifically designed for chemical storage. In most cases the shelf life of a mixed photo chemical is about 8 weeks tightly capped and unused. Used fluids generally last 2 - 3 weeks.
    Most photo chemicals are formulated with a preservative. A replenisher formula is used to extend the working life of a photo chemical indefinitely. A replenisher returns the working ingredients to specifications and adds more preservative. Automated processing machines thrive on high volume because of this principle.
     
  5. I gave up on glass a long time ago. Glass is fragile, breaks into sharp dangerous shards when dropped, and slippery when wet. IMO, these are not good properties for a container to be used in compromised lighting conditions. Everything gets stored in cast off PETE soda bottles. The 1L and 600 ml sizes are most convenient, all things considered. They are robust, have good closures, and best of all, they can be free for the taking. I've no problems getting the claimed 6 month life span from stock solutions of D-76, XTOL, and Dektol when using them. For fixers, keep the used stuff away from the fresh stuff, and don't re-use developers unless you plan run a replenished system.
     
  6. Motor oil containers work great. Yup, sounds crazy, but I do my own oil changes, and keeping my fleet of 5 cars maintained I was throwing dozens of these quart (they hold a liter fine) polyethylene bottles out. The Chevron ones are a nice blue color, the air squeezes out easily, and they store compactly. I've been using them for over a year with lots of different chemicals with no problems. I rinse with paint thinner, then wash twice with a strong detergent like laundry detergent. I just pour the same quart of paint thinner from bottle to bottle. When I was starting out contemplating photography as a hobby, I wasn't thrilled with spending $4 each for bottles, hence the solution.
     
  7. I store my stop, fixer and print developer working solutions in old 2 litre plastic domestic bleach bottles. They have air-tight, child-proof caps and are ideal for the job.
     

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