View Full Version : ideas for a water jacket

brian steinberger
20-Mar-2005, 22:59
i'm planning on using a water jacket for both processing my 4x5 negatives in tanks, and also for tray processing prints. i'm curious if anyone has any ideas about the easiest way to make a water jacket. i just bought a submersible water heater off of ebay that i can use to keep the water jacket at a desired temperature. i just need ideas for how to build something to hold the water that i can put my tanks and trays in. thanks!


21-Mar-2005, 00:59
In the winter my darkroom gets down to about 64, and it gets difficult to process prints in Dektol. In the past, I would place my 11x14 developing tray in a 16x20, and add hot water as necessary. The problem was, I'd forget to check the temp, and my prints would vary.

So I bought a plastic storage container, about 16x20x8 high or so, and mounted a small submersible pump on the side. You could use a 12v fuel pump from NAPA, powered by a small transformer; I happened to have an old 120v one. Place the heater beside the pump outlet, so the exhaust water flows over it, and place a temp probe/thermo at the pump inlet. This container sits in my sink, so leaks aren't a problem. It's very similar in concept to the Jobo CPP system.

In use, I float my developer tray in the water container, held steady on some coat hanger wire, bent in a wide "U" and hanging from the top of the storage container.

This sounds real complicated, but it works great. I also use the container to float BTZS sheet film tubes.

21-Mar-2005, 06:25
The best thing for film tanks would be a picnic cooler. Closed it holds heat better then an open tray. They're insulated. They come with drains. You can get an aquarium pump that can easily handle getting wet.

Nothing really to build. My heating element has rubber sucker feet on it. So does the pump. Just make sure it has water in it when you plug in the heater.

Dan Jolicoeur
21-Mar-2005, 06:44
You can make some nice trays out of pvc sheet stock from mcmaster carr. If you are handy with a power saw, and drill. You can attatch the edges by drill and tapping with a reversable coredless drill. Drill thru both peices with tap drill, and then open up the hole you will not tap. You can put the tap in your drill and run it in and nice and easy. Seal edges before screwing together for a water tight seal. Works great have done it many times for many different size cantainers.


N Dhananjay
21-Mar-2005, 07:00
One of the most convenient ways I have found to keep trays at a constant temperature is the heating mats that are used for plants. Get one of thos emats, set out your trays on it and you are good to go. Cheers, DJ

Gem Singer
21-Mar-2005, 07:04
The problem here in Texas is that the water that runs out of the tap is too warm during most months of the year. During the winter months (December and January) the tap water usually runs too cold. It's easier to warm it up, than it is to cool it down. I find that a Zip-Lock bag filled with ice will cool down a tank, or tray, of chemicals very nicely if I stir it around in the chemical solution for a few minutes (a dedicated bag of ice for each individual chemical solution, will avoid contamination). I make all of my working solutions of developer (for both film and paper) with bottled distilled water. I helps to store the container of distilled water in the refrigerator during the warmer months.

Dave Schneider
21-Mar-2005, 07:30
Maybe I am just a simpleton. I simply let my print wash water overflow into my sink. I made a raised drain in the sink so there's about 1.5 inches of water in the sink at all times. The trays sit in the water and stay at the temperature of my print wash which I keep at 68F. You may have to adjust the level in the sink to keep your trays from floating.