What's the best way/utinsil to maintain a developers temperature at, say 100F, during processing 12X15 paper in Patterson plastic trays?
Thanks,
Thomas
What's the best way/utinsil to maintain a developers temperature at, say 100F, during processing 12X15 paper in Patterson plastic trays?
Thanks,
Thomas
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.
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 (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.
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
Three words: pig warming mats
Drug store heating pads work, but I'm not sure they would maintain the temp you need.
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
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.
The heater would be in a larger tray of water in which you would place the tray of developer.Originally Posted by tgtaylor
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.
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
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