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Keep Your Chemicals Fresh

The initial start when you want to process your own film at home might be a bit expensive, but it's cheaper in the long run. You are able to reuse some of the chemicals that you bought, as long as you maintain its freshness. Check out the article to find out how!

Photo by paperplanepilot

So how do you know when you can still reuse your chemicals and when it’s time to use fresh new ones? To get the maximum value out of your chemicals, it’s good to know how and why your chemicals “expire”. So let’s talk about each chemical and get to know them better!

Developer

Developers are exhausted through hydrolysis (breaking down of developer components in water), oxidation (reaction of developing agent with oxygen), bromide build-up (restrainer or anti-foggants that are given off each time a film is developed), pH change (loss of alkalinity), and actual exhaustion of the developing agents.

Sometimes the developer will change color, but this is not always true for every developer. You should always check the use-by dates on the bottle.

What is surprisingly common is that most people overestimate the amount of developer needed for a given area of film. When you pour that 250ml developer into the canister, most of the developer is there to make sure the film gets wet quickly and evenly. The actual amount of developer agent that does the work is actually not that much.

However, reusing developers is pretty dangerous, because it’s quite unpredictable. It would be better to use develop films “one-shot” using dilute developers and disposing them after that single use.

Stop Bath

Stop baths neutralizes the alkalinity of the developer. Since it’s actually a weak acid, stop baths can be reused over and over again until they lose their acidity. You can check its acidity with indicators or litmus paper. Stop baths are cheap, and if you can reuse them repeatedly, it would be even cheaper!

Fixer

A Fixer slows down all activities that is happening to the film. You can test a fixer by taking a small piece of unexposed, undeveloped film and put a drop of fresh fixer on it. Let it get to know each other for about 20 seconds (it will create a clear spot) then throw the film into the old fixer, making sure that it’s all covered. Time how long it takes for the whole film to get as transparent as the spot that got the early drop (clearing time). Take note of this time or write it on the storage bottle for your fixer. This time will tell you how long to fix, which is twice this time and at the most three times.

A Fixer also results in more and more silver solution called silver thiosulphates. To test this, you would need a silver test paper. But these test papers have a short life and are pretty expensive. So, for this you would need to follow the manufacturer’s guidelines.

Do you have another way to test the quality of your film processing chemicals? Tell us on the comment section below!

written by ilkadj

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This is the original article written in: English. It is also available in: Português & Spanish.