Mixing the Chemicals
Handling, best practice and not drinking it

There are two stages of chemical mixing. The first stage is done to make the reuseable chemistry, specifically the stopbath, the fixer and the wetting agent. In the second stage you need to make up fresh developer just prior to use. The below instructions apply to black and white processing. There is a paragraph at the end of this chapter that discusses colour chemicals.

Reusable chemicals

You can mix this up well in advance of developing your first film. In your ‘STOPBATH’ and ‘FIXER’ measuring jugs mix up each chemical three with distilled water to the appropriate concentrations and then transfer them one at a time to the similarly labelled bottle using your funnel. Make sure you clean the funnel between uses.

For the wetting agent, I simply add one teaspoon of the chemical to my labelled 1 litre bottle and then fill to the top with distilled water. This is close enough to the perfect mix as makes no odds. I believe a similar amount of washing up liquid can also be used instead, but I’ve never tried it. I would suggest trying to find a simple, unfragranced version if you would like to try it. I buy a bulk Ilford kit, so I effectively get the wetting agent quite cheap.

With proper storage, these chemicals can be reused many times. In my experience, I find that (with argon storage) the fixer starts to runs out after about about 16 films, which is 8 sessions of 2 films each. This is less than Ilford state in their guides. Be aware of this. Your fixer is running out if your negatives come out slightly cloudy and a little more purple than before. This was the first sign to me that my reusable chemistry needed to be renewed, so watch out for it.

The stopbath appears to last longer, but I replace it at the same time. I believe the Ilfostop changes colour when it starts to run out, but I have never seen this myself.

As it happens, the stopbath isn’t a critical part of the process. You can just wash the film in water for a few minutes to stop development. However, using a stopbath is supposed to bring a quicker and more uniform halt to the dev process and extend the life of the fixer. I have always used it myself, since purchasing a full ‘kit’ of chemistry is more cost effective than individual bottles. Also, I want to follow the full and standard Ilford process before going ‘off piste’, if I ever decide to do so.

One-shot developer

If you have chosen to use a high-concentrate developer as I have, then you will need to mix up a fresh batch each time. Do this after you have loaded your tank and are ready to develop. This is true for most developers. Below, I describe my process for using Ilford Ilfotec HC, although the advice applies equaly to any high concentrate ‘syrup’, such as Kodak HC-110.

The Ilfotec HC guide tells you to make up a ‘working solution’. It tells you that mixing direct from the concentrated ‘syrup’ is hard. I disagree with this advice. There is a way of working that allows you to keep your concentrate fresh while still mixing up directly each time.

You should have a 100ml brown glass bottle, the sort that kids medicine comes in. As stated earlier, this needs to be completely clean. You need to fill this little bottle from the big bottle of concentrated developer. Be careful while doing this. Wear rubber gloves and work over a sink. Ideally use a larger plastic syringe with a short hose on the end. Once you have filled your little bottle you will draw from it to make up your one-shot developer. This leaves your big bottle untouched on the shelf most of the time. Top it off with argon for long term storage.

You do not need distilled water for the developer. Before you begin mixing a dev solution, you do need a pitcher of tap water at 20oC. I like to keep two 2 litre bottles of tapwater stored in a dark place in my house. This means I always have water at about 20oC ready to use whenever I need it. Alternatively you can adjust the temperature of your tapwater using boiling or chilled water from your fridge as required. It doesn’t have to be exactly 20oC. Within 0.5oC is good enough for me.

Get your measuring jug labelled ‘DEV’ and make sure it is clean. Using your little syringe, draw out a full 10ml and empty into the ‘DEV’ measuring jug. Do the same again, to get 20ml of concentrated developer in your jug. Fill up your jug to 650ml using the water in your pitcher at 20oC. This is your 1:31 dev mix. Now you can ‘wash out’ your little syringe you used to draw the concentrate using this dev mix in the jug. Stir your dev mix thoroughly with a metal spoon or fork.

Please note that you should mix up your developer only after loading your films in the tank. if you were to mix the dev before loading the tank, then there is a chance that developer solution could get onto the films accidentally, either from a surface or your hands. This will of course spoil your negatives.

C41 Colour chemicals

I have sucessfully processed Fuji C200 colour films using the Tetenal C41 ‘colortec’ two bath kit. Mix all the chemicals according to the manufacturer instructions and store them in dedicated bottles. All the colour chemistry is reusable many times. You may read online that the C41 colour chemistry is ‘nasty’. This might be true. However, in my experience using both, the black and white fixer has the worst smell.

previous: Loading the Development Tank

next: Developing Your Film

James Burton on 08 August 2017