Keeping Developer Warm

[evan clarke]

Kane pig warming mats..I have two and my neighbor has two..they hold the temp spot on with the addition of a duro stat thermostat from farmtek with a probe for the tray.

www.kanemfg.com

[Andy Eads]

I've had good results with a submersible aquarium heater (with solid state temp control) and a submersible circulation pump. The set that I have cost about $60 at my local pet store.

[tgtaylor]

Looks like there are plenty of options.

This afternoon I stopped at a Costco and a WalMart. No warming plates at Costo but WalMart had a couple of Osters that looked like they would be perfect. One side has 2or 3 slots for 1.5 QT glass dishes for holding food and the back side is a flat warming plate that would be big enough to accomodate a tray. One advantage of the Oster is that I can actually use it for food instead of being a dedicated lab instrument.

The pig pads look good also if they came in an appropriate size. I went on one site and looked at the "baby" pig version but the descrioption wouldn't open up so I couldn't determine the size(s) available.

Thomas

[Michael Wainfeld]

I use an aquarium heater, in a water bath. Even though I keep the room temp at 68, the developer tends to cool, from evaporation I suppose. Adjustment is a little tricky, because 68 is close to the low end of the scale. It probably would work better at higher temps. Rocking the tray for normal agitation is enough to avoid any hot spots.

[Wayne]

I use an aquarium heater, in a water bath. Even though I keep the room temp at 68, the developer tends to cool, from evaporation I suppose. Adjustment is a little tricky, because 68 is close to the low end of the scale. It probably would work better at higher temps. Rocking the tray for normal agitation is enough to avoid any hot spots.

I use/do the exact same thing like the picture. The temperature in the developer never varies more than a degree, and I don't worry about variations less than a degree. No pump is needed.

[nolindan]

Heating pads from the drugstore will get that hot (well, it isn't that hot - body temperature really). You would probably want two for a 20x24 tray. Keep something thermally insulating between the pads and the bench/sink. You will need a thermostat for color work, without a thermostat the temperature stays quite constant but doing fine adjustment on the temperature is a PITA.

The heating pads are made for damp application to bare skin. They are electrically well insulated so there should be no problem using them under a tray.

It is a good idea to have all the darkroom equipment plugged into ground fault interrupters - mandatory anywhere there is water or piping. Especially mandatory here - be it aquarium heaters, pig mats or heating pads.

[Michael Clark]

The Pig mat site did not say anything about using them in the sink with water and chems around, are they designed to be used that way?

Mike

[Ken Lee]

What's the best way/utinsil to maintain a developers temperature at, say 100F

If your room is 100 degrees, then the developer will stay at 100 degrees - and so will all your chemistry: there will be no need for fancy or dangerous equipment. It shouldn't be hard to warm up your bathroom with a small electric heater.

I found a nice brand of heater at my local Ace hardware store, called Pelonis® Ceramic Heater Fan (HC0120). it costs around $27.00, and it's small, light, and fairly quiet. Amazon carries this same model.

I place mine on the floor, and warm my darkroom to exactly 70 degrees when developing sheet film in trays, and around 80 degrees for Pt/Pd.

If you're concerned about dry air, you can get a humidifier from your local pharmacy for around the same price.