I am in the process of setting up my first ever darkroom in the basement laundry room. Is there a water temperature regulator that can be hooked up to a regular faucet without getting into any complicated plumbing? I know that the water temperature is critical to the film and paper developing. How do you handle this problem in a home darkroom without a temperature control?

-- Lee Freedman (leef@localnet.com), February 08, 1998

Answers

There are such gadgets, but they do cost a fair bit.

If you are just starting out in darkroom work, I suggest you initially just get a good thermometer.

For B&W film processing, you should easily achieve + or - 0.5 deg F. Get some cold water and some warm water (I use a microwave). Mix them, creating more water than you need, at exactly the right temperature, or slightly warmer if the developer is too cold. Then dilute the developer with this mixture.

Or you can bring the undiluted temperature to the right temperature by immersing it, in its container, in a water bath.

Developing prints is less critical. If the developer wants 20 deg C, make sure the room is about that temperature, and mix dilute the dev to about that, and it will be fine.

-- Alan Gibson (gibson.al@mail.dec.com), February 08, 1998.

To wash film I mix hot and cold water from the faucet in a largish vessle to the desired temp (75 deg. F) and dip out of that and pour into my developing tank. While deveolping I use a deep 11x14 tray (a dishpan will do) half full of water at temp with vessles containing each chemical. My tray is a stainless steel "hypo" tray, 5" deep with a mylar self sticking heating element on the bottom and a home made proportional controller. A light dimmer would also do. Dev Tech makes a temp controller for $100 (from B&H photo) that could do the job as well. If you are electrically inclined you can get the mylar heater from Minco Products, 612-571-3121. Call for a catalog. I used model HK5184R26.4B

-- Tim Brown (brownt@ase.com), February 09, 1998.

Temperature is critical for developing film. Much less critical in the darkroom with developing paper.

Maintain at least 3 or 4 times as much water as you need in graduated cylinders in a sink or bath at the target temperature.

Also, its a good idea to pre-rinse for a few seconds using the above water to get the developing canister to the right temperature.

After developing, pour some in small graduated cylinder to get an end reading to see how close you came to the recommended temperature throughout the developing process.

2 more tips: wear rubber gloves when you agitate the canister and set the canister in water between agitations.

As far as developing paper, room temperature is the best control. This is not as critical as film developing solution temperature. (Color printing is another story)

-- peter o'toole (potoole@mn.uswest.net), April 03, 1998.

I have been using a Delta I temperature control device. It is basicallt a 3" dial thermometer that mounts under a faucet. It costs about $60. and seems to work very well. I set the water temperature and the temperature holds steady at the setting.

-- Robert Orofino (www.rorofino@uscgelc.gov), June 10, 1998.

I've been through the water temp issue a few times in different darkrooms. The Delta tee with temp dial is a good compromise. The automatic, thermostatic temperature mixing valves are now quite expensive, over $400, and need some plumbing. An alternative is a shower temperature mixing valve, which new is still over $200 and requires some kind of plumbing. I got one of these used for $100 and it works fine. The problem with mixing valves (and tees as well) is that when the outflow valve is closed, hot water enters the cold water line. When you open the outflow valve again, you get a blast of hot, hot water. The answer is a one-way valve on the cold water side, needing more plumbing. Otherwise, live with it, or turn off the input valves between uses, an annoying bother. Another thought: adjust the water temperature to the room temperature and use time temperature charts for film developing time. No drift this way! No need for an expensive temperature compensating developing timer. And for the reasonably comfortable range of room temperatures, this is viable for black and white, in my experience. In any case, there is nothing like your own darkroom, "no matter how humble!" Best wishes.

-- Todd Foster (ptoddf@aol.com), January 20, 2000.