Sous vide emersion heater for larger trays?

[keithostertag]

The only reasonable place for a darkroom at my home is in my unfinished basement. it is very light tight, but stays cold most of the year, ranging from about 55 to a high of 65 degrees during a summer heat wave. So even though I only want to process B&W film negatives, I am looking for a way to water bath my 5x7 sheet film trays to 70 degrees or so. Heating the room isn't really a viable option currently.

Rather than use something like the standard Patterson 5x7 developing trays I plan to use larger glass cooking casserole dishes- the glass will hold heat better but they do take up considerably more real estate.

So I am wondering if I could use one of those inexpensive sous vide immersion heaters effectively. In my case, I need a "sink" for a water bath large enough to hold three trays but not too deep. Do those sous vide heaters pump/circulate the water? In your experience, would they be good for circulating water in a wide but not very deep container?

In the past I used a drum roller to process my 5x7 sheet film, and I may move back to that in the future. But I just wondered if this water bath approach might work.

Thanks,
Keith

 

[abruzzi]

the challenge willl be as you hint at--the sous vide will have a minimumdepth of fluid. I have the Cinestill one, and while I'm not at it at the moment, I'd guess the minimum fluid level is probably 1-2 inches. which would be enough to float most dark room trays. So you may want to arrange a grid of bricks or other heavy objects so the trays aren't on the bottom of your sink, but sitting higher on the objects.

Edit--maybe you can find a baking rack that sits high enough?

 

[Paul Howell]

I would get a water proof heated pet pad, use stainless steel trays for better heat conduction.

 

[markbau]

Check out a home brew shop. They have heater pads that are designed to put a keg of beer on while it ferments to keep it at a constant temp. I use one for my print developer and it works perfectly.

 

[jvo]

i had a below ground basement in NY that was a pretty steady 68 degrees year round - varied by 2 degrees, if at all. on some winter days i found it necessary to keep interrupt my sessions with an hour warm-up break!

the upside all the chemicals never needed temperature controls of any sort!

 

[Donald Qualls]

Here's one way to use a sous vide with trays: Get a dishpan or laundry tub deep enough for the sous vide unit to be sufficiently immersed and broad enough to hold all the trays you need, plus leave some area open, and put milk crates or similar in it to support your trays. You want just enough water depth above the crate surface so the liquid in the tray will be deeper (else the trays will float).

The sous vide heats the water in the tub, and can also heat the chemical bottles while you're getting things ready in the darkroom, and when you're ready you'll fill each tray so it sinks in the correct position -- still with sufficient freeboard that you don't have water slopping in or chemicsl slopping out, but deep enough for heat transfer. Stainless or (unchipped, please) porcelain coated trays will help here, as they're significantly heavier than plastic and will stay put more readily.

If you don't/won't have a way to fill the tub with prewarmed water, you'll need to allow an hour or two for the water bath to come up to temperature, of course...

 

[Paul Howell]

JVO made a good point, what the temp of your basement? If close to 68 then maybe a electric radiator with baby oil would keep your space at 68 without any fuss. Here is the desert my problem is cooling, in the summer I crank the AC down to 70 while in the darkroom.

 

[otto.f]

I'm not a fan of seeking stability of temperature in a water bath, much too soon cooling off. I use this under my developer tray, stopbath and fixer are much less critical in temperature.

https://www.amazon.nl/LERWAY-Verwar...vtargid=pla-423114385625&psc=1&language=en_GB

There are other brands and sizes too.

 

[AgX]

JVO made a good point, what the temp of your basement? If close to 68 then maybe a electric radiator with baby oil would keep your space at 68 without any fuss.

What is a "electric radiator with baby oil"?
I know electric heaters, shaped like a classic radiator from a central water-heating, but filled with oil. Got such myself, but your wording puzzles me.

 

[Paul Howell]

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[MattKing]

I think that "baby oil" may be more commonly referred to as "mineral oil" in the heater world.

 

[wiltw]

The only reasonable place for a darkroom at my home is in my unfinished basement. it is very light tight, but stays cold most of the year, ranging from about 55 to a high of 65 degrees during a summer heat wave. So even though I only want to process B&W film negatives, I am looking for a way to water bath my 5x7 sheet film trays to 70 degrees or so. Heating the room isn't really a viable option currently.

Rather than use something like the standard Patterson 5x7 developing trays I plan to use larger glass cooking casserole dishes- the glass will hold heat better but they do take up considerably more real estate.

So I am wondering if I could use one of those inexpensive sous vide immersion heaters effectively. In my case, I need a "sink" for a water bath large enough to hold three trays but not too deep. Do those sous vide heaters pump/circulate the water? In your experience, would they be good for circulating water in a wide but not very deep container?

In the past I used a drum roller to process my 5x7 sheet film, and I may move back to that in the future. But I just wondered if this water bath approach might work.

Thanks,
Keith

The sous vide has a minimum water depth required. My unit minimum to function is 62mm, and then there is the clamp to hold it upright is 140mm minimum. And then not all units can control down to 68 degrees, but many have higher lower limit.

 

[MattKing]

You could combine a sous vide with some sort of recirculating pump to feed and drain a surrounding insulated tray.