Temperature control for C-41 tank/tray processing

[mfratt]

I'm in the process of setting up a darkroom for myself, and I'm going to try to get myself set up to process C-41 for 4x5 sheet film. I've only processed black-and-white in trays before, never done color, but I've done my share of research and I get the gist of it.

I'm probably going to do it in dip-and-dunk tanks, just so I don't have to get my hands too close to the chemistry. I will of course be taking necessary precautions regarding ventilation and skin/eye protection.

For those of you processing C-41 without a processor like the Jobo, what do you use for temperature control? I don't want to just get the temperature right at first, because it will no doubt cool down and is too imprecise for me.

I was planning on getting a large tank to fill with water held at a constant temperature, and keep the smaller tanks inside that bath so as to maintain their temperature. Is there an underwater heater I can buy for this? If so, where can I get it (couldn't find anything on a Google search other than some fish tank heaters, none of which specified whether they went up to 100F or not).

Also, while I'm on the topic, do you have any recommendations for a light-tight window vent? I'm a college student on a bit of a tight-ish budget, so I can't go crazy but I'll do what I have to do to make my darkroom work out.

Thanks for you advice, and any other tips for a C-41 newbie you could provide would be appreciated.

 

[mfratt]

Thanks, Greg. I'll pay a visit to a pet store and see what I can find.

I can just picture asking someone, "Do you have a heater that goes up to 100 degrees?" They'll probably think I'm trying to cook my poor fish for dinner!

 

[markbarendt]

Double hot plate at Wal-Mart and two stew pots.

Bought mine for $32 and the stew pots were leftovers. Worked great.

 

[mfratt]

Oh, nice! That will make my life much easier if I can find one like you've got. Would ya know that its actually cheap too? It would probably be $249 if it were marketed at a photographic accessory instead of an aquarium accessory...

 

[MattKing]

Would something like this help:

Dead Link Removed?

 

[Mike Wilde]

I too use aquarium stuff, to heat a cooler (eskie in some parts of the world) filled with water as a tempering bath for tanks and bottles. I use narrow mouth boston round bottles for chems, so the bottels don't float arounf when mostly full. They are slow to heat up, but also slow to cool. I when processing 4x5 I boot the pre-tempered stop and fix and bleach out of the tempering bath during processing and they keep warm sitting in the sink, while the bakelite like 4x5 tank and hangers go in to pre warm. My tank holds 6 hangers, and will do them with only 1L of chems, which is the size I mix and store for my C-41 smaller format use as well.

The analog bimetallic controlled fish tank heaters (glass tube with screw knob adjustment in top) work just fine. Bust the knob stops off, or move the knob up the shaft to miss them, and the thing will merrily heat up. Be sure to keep water levels up to cover the thermostat section if using theis type of heater