Can film processing chemicals be kept for re-use?

Dear friends,

 

Just wondering if the chemicals I used for processing film can be

kept for re-use over a couple of weeks. I have discarded the

developer 'cos I know it is not advisable to re-use, but how about

the stop bath and fixer? I use the following:

 

Ilford IN-1 indicator stop bath.

Ilford Hypam rapid fixer.

Ilford Ridfix

 

All have been used for two rolls previously and kept in tightly

capped bottles.

Stop bath has an essentially indefinite shelf life.

About the only way it can go bad is if it gets too

much alkali (developer) in it, and if this happens,

the indicator will change color. OTOH, it's so cheap,

I often make up a new batch when I replace my fixer.

<p>

Fixer keeps for several months, but it also has a limit

to the amount of silver halide it can dissolve, so it

wears out after a number of rolls of film. The capacity

varies, depending on the type of film and fixer. Capacity

may be listed on the instruction sheets, but a

rule of thumb is to put a piece of undeveloped leader in

fresh fixer and time how long it takes to clear. After you

use it awhile, repeat the experiment. When the

clearing time for old fixer becomes double what it was for

brand new fixer, it's time to throw it out.

<p>

You can also get a bottle of hypo-check to test your fixer.

This is a chemical that will

form a white precipitate when you put a drop of it in

exhausted fixer.

Yes you can keep using the stop bath until it changes color (it normally goes a purplish color), and then change it.

With the fix you can keep on using it, however test before you use it. This test normally involves taking a piece of exposed, undeveloped film (I tend use the leader/tongue that usually gets cut off and discarded before loading onto the reel), pouring some of the fix in a small dish or cup and then put the mentioned piece of film into it and time how long it takes the film to go clear. This should normally happen in around 3-5 minutes. If it takes any longer then 6 minutes, I would say the fix is exhausted and needs replacing. Also the test is good way to work out how long you need to fix your film for... unless your using Kodak T-Max films, then give it extra third of the time to fix properly.

Another good note to mention, make sure you invert the bottles a few times (but don't shake, you don't want any air bubbles forming) you store the chemicals in, before you use them. This way you mix the chemicals up and mix up any chemical/water separation that might happen over a long storage period.

Also if the fix changes from a nice clearish color, to something with a brown tint, dump it. Another good sign that it is dead.

 

Stu :)

Information about keeping properties and exhaustion rates are usually available from the manufacturers (check the webistes if not supplied with the product). Some developers can be reused if not diluted (check the instructions).