View Full Version : Darkroom Ah Ha Moment - Keeping it cool

Steve Feldman
5-Sep-2011, 17:23
I'm sure someone out there in traditional darkroom land has done this, but I've just now discovered this on my own. I'm in Sunny Southern California. Make that HOT! Sunny Southern California. I was mixing up developer for black and white print processing. The cold water in my darkroom comes out at over 80 degrees. I added a few handfuls of ice to the water before mixing it into the Dektol. Thus getting it all down to 68 degrees. After 2 prints I checked the temperature and it was up to 75. I didn't want to add more ice because it would dilute the developer. So I thought for awhile. Hmmm . . . Went to the fridge and took out a frozen gel pack that I use to ice down sore muscles. Placed it under the developer tray. Five minutes later the temp in the tray was 68 and held there until my print session was done. Cool huh?! (Pun intended). An added but unplanned benefit was that it made the tray self rocking. Didn't have to lift one side and then the other. Just gently push down one side and then the opposite side. Easy. I'm so proud of myself.:)

Can I patent that?:rolleyes:

5-Sep-2011, 17:30
that really is a good idea....off to target to buy some ice packs!

6-Sep-2011, 04:55

I use those packs as well. I'm in CT and because of the orientation of my darkroom (make that kitchen sink, heh), I get a lot of sun. I use a daylight tank in a cat litter water bath and the packs work great. I just had to experinent with the size and number of the packs to get the cooling effect right.

Good trick.


6-Sep-2011, 05:33
This is a neat solution to an otherwise difficult problem. Thanks for sharing.

6-Sep-2011, 07:54
I use these:


6-Sep-2011, 08:06
What problem are you having with Dektol at 75 or 80F?

Steve Feldman
6-Sep-2011, 09:16
What problem are you having with Dektol at 75 or 80F?

Lower contrast and a mottled appearance. Depends on the paper in use.

Steve Feldman
6-Sep-2011, 09:19
Darn! I knew I shoulda taken out that patent sooner.:eek:

Jim Andrada
2-Oct-2011, 21:20
Glad I stumbled on this thread - I'm just getting back into LF film and have been puzzled by the same issue - I have a Jobo temp controlled processor but it works by warming the water bath - not what one needs in Tucson in the summer when the "cold" water comes in over 90 degrees and the temperature in the garage area I get to use is over 100. At one point I was thinking of a thermoelectric cooler but something like this might work.

2-Oct-2011, 22:08
You can get Small gel packs that are meant for soothing muscle aches that can be frozen or heated in the microwave.


Brian Ellis
3-Oct-2011, 08:22
There's nothing magic about 68 degrees. Any temperature within reason will work fine, temperature (within reason) only affects time. I used to start with a temperature of 75 degrees, by the time I was through it was usually around 80 or 65 in my Florida darkroom (depending on how I set the air conditioning). Actual time was adjusted automatically by the Zone VI Studios Compensating Developing Timer but even if I hadn't owned that timer I could have adjusted about as well by eye.

Even if you can maintain the temperature at some fixed number throughout the length of the darkroom session, that doesn't mean your printing times will be consistent from start to finish since the developer loses strength as you make prints (there are ways of dealing with that too and if you're making the same print over and over, as for a portfolio, then they're worth using but IMHO they're too big a pain to worry about when you're working on several different prints in the course of a session).

So to me there's no real good reason to worry about keeping the print developer temperature at a constant 68 degrees (or any other number within reason). I know that Ansel Adams maintained that the character of some developers changed with significant changes in temperature. All I can say is that if there was such a change with the developers I used either my temperature changes weren't great enough to cause it or the change was so subtle that I couldn't see it.

Obviously all of this is just my opinion (though based on years of darkroom experience), others may disagree.

Brian C. Miller
3-Oct-2011, 09:18
When I'm using my Jobo CPP2, I hook the cold inlet to a fish pump in a bucket of cold water with ice packs. Then the water is guaranteed to stay cold.

Otherwise I adjust for temperature, and maybe dilute the developer some more. So far, so good. (barring an out-of-whack thermometer, but that's been replaced now.)

Jim Andrada
3-Oct-2011, 11:01
Happened to be reading the Jobo manual and noticed that for cooling they recommend filling any unused bottles with water and freezing them and putting them (or some "blue ice" packs) directly in the water bath They say that the built in heater will compensate adequately.