Does anyone know of online plans for a tempering bath?

[steven_clark]

I always thought it would be nice to be able to process my own color materials. The problem is that I have alot

more time than money and tempering baths cost more than I can afford to pay in the latter. Does anyone know of

plans or instructions posted somewhere online for building a tempering bath at the heat levels needed for E6 and

C41? I'd call it a Heathkit Jobo, but I don't know that anyone would get what I meant.

[mike_earussi1]

I never needed one. I just used a Beslar motor base with drums and heated the chemistry in a plastic tub using fish tank heaters I picked up cheap at the Goodwill store. I found that as long as I kept the timing the same the process was repeatable.

[victor_ho2]

Steven

Before I had a darkroom, I used a bathroom as my processing lab for E6. It's been a while but the principles would be the same. Water loses temp rather slowly. A larger body of water will get cooler more slowly. I used the bath tub filled to the point where the 2 liter E6 bottles would just about float. The temp of the water was measured with a lab grade [ in tenths] thermometer and i kept the temp at about 3 degrees C above the process temp. This kept the chemicals at about the right temp. You'll need to compensate for room temp etc. I checked the temp of the bath regularly but need to adjust about once every hour. This is crude but all my E6 was developed without losing a roll.

 

By the way, to keep the developing tank - stainless steel - at temp, I used the sink to maintain a constant water temp bath. Smaller volume of water in the sink meant more fine tuning of temp.

[aaron_muderick]

I made a neoprene coozy for my steel development tank. Uninsulated, the liquid temperature would drop from 100.4F to 82F in six minutes. Two layers of neoprene and a warming pre-bath changed that to only three degrees drop over the same time. It had an added bonus of increasing the tank diameter enough so that I could use a Beseler Motor Base for continuous agitation.

[aaron_muderick]

Here is a link to everything I did:

http://www.kryptosinistographer.com/2008/03/at-home-e-6-pro.html

[edomazlicky]

Not exactly on the subject but this link is interesting:

http://home.hccnet.nl/e.vd.logt/htm/hardware_uk.htm

 

This person made a home-brewing tank with precise temperature control. You can take a lot from the principles here and apply them to a tempering bath. The basic idea is to use a LM92 temperature sensor (0.33 accurate!) combined with a heater and Solid State Relay (basically a dimmer for the heater) all controlled by a PID algorithm run by a microprocessor or computer. This is on my list of things to do. If you did it right this could be more accurate than a Jobo.

[aaron_muderick]

You can use a standard (and cheap) aquarium heater. Most can be hacked/tweaked to change the range of temperature they work within. Once set, they are pretty accurate and consistent.

[steven_clark]

I think that temperature sensor might be the missing component. One of those, a microcontroller, some relays, and some nichrome are probably all you really need in terms of electrical components.

[aaron_muderick]

All aquarium heaters have built-in thermostats. You don't need a microcontroller or anything complicated to make a switch that flips on/off at a specific temperature.

[steven_clark]

I thought the problem was that Aquarium heaters didn't usually go hot enough. The chemistry temp's supposed to be 100 Fahrenheit right?