Waterless Jobo CPE2

<p>I use a Jobo CPE2 processor for C41, obviously with the water bath. I would like to try to use my 2509n tank for traditional film, and it would be a great timesaver if I could do without the waterbath - certainly when using my Paterson 35mm/roll film tanks, or the Orbital processor there is no water bath necessary.</p>

<p>What I am proposing is to turn the thermostat right down below ambient, and perhaps barely covering the element with water as a safety measure, but not filling the water bath up to reach the tank, so its temperature will not be affected by the bath. It should save a long warm up t ime.</p>

<p>Is there any technical reason why I need to fill the waterbath completely before starting to process? I am loath to risk damaging the processor at all obviously.</p>

<p>Any opinions welcomed, thanks.</p>

<p>N ick</p>

 

<p>That's how I'm using mine but I don't put any water. You do need to wight it down a bit though, I use two small sandbags.</p>

<p>And what the heck is the problem with havig water in it? In the plastic of the CPE 2 its carved: Do not heat without water!</p>

<p>What can that possibly means folks?<br>

Hello wake up!</p>

<p>Erik - The problem is that even at B&W temperatures the CPE2 takes some time to stabilise, and so, as I made perfectly clear in my original post I was intending to keep the thermostat turned down below ambient so the heater could not turn on and, after listening carefully to the experence of anyone who was kind enough to contribute, I might also insure against the unlikely, by covering the element with a little water.</p>

<p>I am not so daft as to turn on a heating element without water, no matter what is written or not written on the processor!</p>

<p>The reason behind my post was that I wished to know if there were any additional reasons for not running the motor without a full water bath - for example to lubricate nylon bearings or to maintain stability (as appears to be the case).</p>

<p>Sorin - Thank you for a useful response based on your actual experience.</p>

<p>Why not just fill it with room temp water. You get your stability due to the weight of the water and protection in case the heating coil turns on.<br>

With the weight of the water the lifting and lowering of the lift is so much easier.</p>

<p>Jobo do have a different roller for running the CPE2 without water as the water does lubricate the standard roller as you suspected.<br>

Easy Running Roller<em> Item No. 92167</em> <br /> Roller<em> Item No. 07007</em> <br>

http://www.jobo.com/web/Spareparts.348.0.html<br>

You must put some water in the bottom to cover the heating element before switching it on.</p>

<p>Thanks for all of the help everyone, I think I know what I will do now.<br>

Danny - Thank you for your info re the lift - The reason that I was doubtful about using water from the tap was that this is usually a few degrees colder than B&W processing temperature, and if I were to fill the processor it would cool the tank down. An empty, or nearly empty, processor where the tank was in air does not appear to cool off apprecciably over the duration of B&W development. On the other hand if I need to heat a full water bath to 20 degrees or so it takes some time to stabilise, hence my desire to avoid it if possible, and my request for help.</p>

<p>If you mix hot and cold tap water to as close as 20 degs as possible [aiming slightly below], and use that to fill the jobo, it shouldn't take long to stabilise.</p>

<p>William</p>