Keeping Developer Warm

[tgtaylor]

What's the best way/utinsil to maintain a developers temperature at, say 100F, during processing 12X15 paper in Patterson plastic trays?

Thanks,

Thomas

[Scott Walker]

I have a large sink and all my trays sit in about 2 inches of water. The water is running and temperature controlled. I use a piece of PVC that I turned on the lathe to fit the sink drain. The PVC has a couple of small holes at the bottom to allow some draining of water from the bottom but most of the water drains over the top. Not great for conserving water but it sure works well.

[cyrus]

I don't know about 100F but other than putting the tray in a larger container of warm water, you can also try an immersion cup heater, or better yet, an aquarium heater (http://www.amazon.com/Aqueon-Pro-Submersible-Aquarium-Heater/dp/B003GKL4J2/ref=sr_1_2?s=pet-supplies&ie=UTF8&qid=1326995822&sr=1-2) (which has a thermostat) placed directly into the developer. But in either case it is a good idea to constantly monitor the developer temp using a thermometer. In my case, I find that I can work with colder or warmer temps for BW photography - it just takes a bit longer to get fuller blacks when the developer is cooler. The important thing is to keep the temp relatively constant, even if it is cooler than the standard 67 degrees F.

[tgtaylor]

Thanks Scott. Unfortunately my bathroom sink (my "darkrooms" wet side is the bathroom) is too small. That size of tray will fit in the kitchen sink but then I would need to light-proof the whole front of the apartment.

Thomas

[Phil]

Three words: pig warming mats

Drug store heating pads work, but I'm not sure they would maintain the temp you need.

[tgtaylor]

Thanks Cyrus.

The aquarium heater sounds like a good idea but my concern is will it work for a relatively small volumn of developer in the tray. This will be for an alternative process and the chemistry is more expensive than that for regular B&W and I will be processing only a couple at a time.

Thomas

[jeroldharter]

That seems pretty warm but i assume you have a good reason, maybe for toning? You could try a pig blanket. There are several threads about them. I thunk they are used in farming as warming mats for pigs so they are water resistant. Not sure if they go up to 100 degrees.

Patterson or Kaiser used to sell an electric tray warmer. I rarely see them available and i think they were more common in Europe.

Otherwise a water bath is about it. An aquarium heater plus a pump to circulate the water could work. If you do that, add hot water initially or you will wait forever for the heater to warm the water. There is also a submersible Doran water heater that has a manual thermostat. It work best in a large tray because it is rather bulky, much more heavy duty than an aquarium heater, and has a stiff cord.

Also, Phototherm makes waterbath trays of various sizes. They are just plastic tubs and on the back left corner wall they attach a heater with thermostat and recirculating pump. Those easily get to 100 degrees.

[jeroldharter]

Thanks Cyrus.

The aquarium heater sounds like a good idea but my concern is will it work for a relatively small volumn of developer in the tray. This will be for an alternative process and the chemistry is more expensive than that for regular B&W and I will be processing only a couple at a time.

Thomas

The heater would be in a larger tray of water in which you would place the tray of developer.

[cyrus]

PS: I wouldn't mess with anything electrical near water unless I was absolutely sure that it was not going to fry me. I would strongly recommend testing whatever heater you get before you stick your hands in the water, to make sure there are no stray currents.

[tgtaylor]

Thanks everyone!

Looks like food warming trays would work and they are the right size. Also Christopher James's idea of using an electric crock pot would also work and may be the best idea for this particular process. The development stage is up to 10 minutes and need is to keep the solution above 78F at which temperature the borax percipitates out of solution. James recommends starting with the developer at "80 to 85F" but that seems awfully close to 78F. Conversely Crawford recommends 100F and it seems likely that the developer would remain above 78F with that starting point.

This is for the Kallitype process.

Thomas

[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) (http://www.acehardware.com/product/index.jsp?productId=1275033&kw=pelonis&origkw=pelonis&searchId=59974332473). 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.