DIY Temperature Control Water Bath for Color Analog Film and Paper Development

Motivation

Keeping chemicals at a stable temperature is important for C41 color film developing and RA4 color paper development. It is possible to warm chemicals to the necessary 100 degrees Fahrenheit by placing them in a warm water bath from the hot water faucet, but this process requires continuous monitoring and replenishment of the hot water to keep the temperature up. This is an even larger problem when working with color paper developing since many sheets of paper must be developed over a long period of time and it is impractical to correct the temperature on every step.

Materials

• Pump
• Temperature Controller
• Heating Element
• Bucket — big enough to hold everything
• Small Basket — to separate the heating coil from the bottles of chemicals.
• Power cable to hack — You can use any standard power cable that plugs into the wall. I used the wall side of a broken apple power adaptor.

Tools

• Wire Strippers / Knife
• Tape

Wiring

Wire the pieces together as shown. You will need an additional piece of wire for the middle red connection, but you can also cut this from the power cable.

Small Scale Test

You should now be able to test the setup by inserting the temperature sensor and heating element in a small cup of water and setting the controller to a temperature following the instructions that come with the temperature controller. At this point you should be able to observe the system keeping the water at a stable temperature.

Full Setup

Now that you have the full setup, you’re ready to develop with relative ease! Yay!

Where to get Chemicals

• RA4 Developing Chemical Kit for Color Paper
• C41 Developing Chemical Kit for Color Film

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