The heating mats work better if they are well insulated from the bench. Place the heating mat on a sheet of Styrofoam and put the tray of pre-heated developer on top of the mat. Try it with water first to see what temperature the whole thing stabilizes at.
Does anyone have a recommendation for a tray heating mat? I've recently retired and downsized but I still like to make lith prints with my collection of outdated papers. I started in photography in 1974 after I enrolled in a college elective course and fell for the darkroom magic. I also have a lot of analog equipment which I'm downsizing as well. Send a message if seriously interested. Thanks for the help
From the description:I got one of these recently:
That's generally way too hot for most darkroom work with the possible exception of offgassing carbon printing gelatin 'glop', which could be done at the lowest temperature setting.3 adjustable temperature levels (140-212℉/60-100℃)
How long did you test for, and did you start out with cold water in the trays or warm? If you intend to use this to gently heat up the liquid in a tray, then it'll work. It'll also work for lith development where the developer spends only a limited amount of time in the tray before it's being dumped or at least removed from the tray again (assuming one-shot development with a developing time up to ca. 15 minutes).testing with trays with water seems to work.
From the description:
That's generally way too hot for most darkroom work with the possible exception of offgassing carbon printing gelatin 'glop', which could be done at the lowest temperature setting.
Now, a tray of water will dampen the temperature response somewhat so at least the heating of they contents of the tray will be slowed down; the larger total surface (walls of the tray, surface of the liquid) may in fact result in thermal equilibrium being reached at a lower point than the temperature setting on the mat. This depends mostly on whether the temperature control is thermostatic (good news: it likely isn't as this would add $0.10 to the bill of materials) and the actual power this mat works at. However...since the mat is designed to keep pots of food at a 60-100C temperature, which is a similar thermal profile to a photographic processing tray (similar liquid volume, roughly similar geometric parameters), the expectation is that your tray contents will drift up in temperature until they reach more or less the temperature set on the mat.
How long did you test for, and did you start out with cold water in the trays or warm? If you intend to use this to gently heat up the liquid in a tray, then it'll work. It'll also work for lith development where the developer spends only a limited amount of time in the tray before it's being dumped or at least removed from the tray again (assuming one-shot development with a developing time up to ca. 15 minutes).
That's its intended purpose.As an aside IMHO, the only way this would work for food warming is for hot plates of food to be placed on the mat
I have some and thought about those, but the lack of a temperature control had me look elsewhere.My Dad used the seedling mats, he put them under a shallow (maybe an inch) sand layer in a tray. He used for keeping seed pots warm for germination. Worked forever. This was 35-40 years ago. It was magical to see how well it worked.
I have some and thought about those, but the lack of a temperature control had me look elsewhere.
I have some and thought about those, but the lack of a temperature control had me look elsewhere.
From the description:
That's generally way too hot for most darkroom work with the possible exception of offgassing carbon printing gelatin 'glop', which could be done at the lowest temperature setting.
Now, a tray of water will dampen the temperature response somewhat so at least the heating of they contents of the tray will be slowed down; the larger total surface (walls of the tray, surface of the liquid) may in fact result in thermal equilibrium being reached at a lower point than the temperature setting on the mat. This depends mostly on whether the temperature control is thermostatic (good news: it likely isn't as this would add $0.10 to the bill of materials) and the actual power this mat works at. However...since the mat is designed to keep pots of food at a 60-100C temperature, which is a similar thermal profile to a photographic processing tray (similar liquid volume, roughly similar geometric parameters), the expectation is that your tray contents will drift up in temperature until they reach more or less the temperature set on the mat.
How long did you test for, and did you start out with cold water in the trays or warm? If you intend to use this to gently heat up the liquid in a tray, then it'll work. It'll also work for lith development where the developer spends only a limited amount of time in the tray before it's being dumped or at least removed from the tray again (assuming one-shot development with a developing time up to ca. 15 minutes).
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