I've got a heating element in a ~13x9x4 plastic container. It seems to heat itself to about 50ºC. The "tank" was my wife's grandfather's (along with most of my other darkroom equipment). I'm going to build a new one using a water heater element connected to a water heater thermostat to give a better control on my temperatures. For RA4, my current setup is perfect, but for C41, I need the water to stay hotter but not too hot.
I use what is basically on of these.
At the very low setting it heats water to exactly the temperature I want.
I just put my flasks in there and wait and hour or more for them to get to the right temperature.
Then I put my reel tank in until it heats itself up. There have been no problems so far with a drop below crucial developing temperature.
I've ordered a customized temperature controller in stainless steel which has a capacity to store 8 1 liter bottles of chemicals (I intend to use this for E6 too). I got quite a bargain and I'm hoping that the product turns out as promised. It has an accuracy of 1/2 degree centigrade. Hopefully this will take my developing to a more accurate level and make it trouble free. At least for C41 and E6. I'll post some pictures when it arrives. Thanks everyone for your feedback and response.
Can you please provide specifics of the controller or a link to the website? TIA!
Originally Posted by ashokgoyal42
I use Unicolor 3 bath press kit and prefer processing at 30C. It will work down to room temps as well, but I didn't try that. At 30C, the temp is much easier to control (microwave plus water bath), plus an added benefit is that the processing time errors one may inadvertently introduce become less important. 5 seconds of 3.5 minutes is a bigger problem than 5 seconds of seven minutes. Works fine with no noticable colour shifts.
Instructions call for a one minute pre-soak. Tried with and without with no noticable difference. I do also put the tank in the water bath for a few minutes together with the chems. I use steel tanks and rolls for 120 and plastic for 135. Find those combinations easiest to load.
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Originally Posted by tnabbott
My system has been ordered from a company based in New Delhi called Sensors India. This is the link to their website -- http://www.sensorsindia.com/
What other detail can I offer you? What specifics would you like to know. Glad to help.
Sorry for the bump, but I was wondering about the feasibility of stovetop C-41.
I have a portable electric stovetop (kinda like a hotplate thingy) that we use when we go camping. An electric range/hot plate of sorts like this.
Basically I plan to put a pot of boiling water and place the bottles of chems in there. Then while I process, I leave the patterson tank in the same pot in between agitations. Will this work? Or will it melt my tank?
The heat that those things are designed to produce is probably much more than you would need, and it is maybe not easy to regulate it to the right temperature, consider also the risk of "boiling" your chemistry, melting plastic objects etc.
A food-warmer is probably a better choice, you don't risk melting anything. You then put a basin over the food-warmer (so it must have a flat surface, or be of the kind which is fillable with water) and let the water, tank, and chemicals' temperature stabilize, after which you should be ready to operate safely.
Probably something like that:
You can also find Jobo "warmers" quite cheaply on auction sites. They don't have any rotating ability, only keep the chemicals at the right temperature. Something like this:
Hello, I have said this before, but I hope it will be helpful:
Stuff you need:
*Semi-insulated or insulated container. No need for insulation per se, but makes the whole thing more efficient, I use a cooler chest.
*PID-thermostat, very cheap from china via ebay, or expensive thru your local industry supplier
*PT100 sensor, as above
*Depending on the pid-thermostat you might need a relay, best is a solidstate relay
*Heating element (I use a 300W travel immersion water heater)
This gives you a very consistent setup for little money. Mine cost less than $50 bucks. And it's self calibrating and extremely adaptable. Could be used for a large tank for huge RA4 printing drums, or a small thing for doing single rolls of 35mm.
Don't overheat C-41! I once did a pre-soak at 50C or so and ended up with red spots (in reverse) so it looks like I damaged the emulsion.