Advice on how to get correct E6/C41 temperature on Jobo CPP3?

[dede95064]

Hi,

I have a Jobo CPP3 and I'm having difficulty getting the correct 38 degree temperature as I use the auto mode. If I let the machine do its thing and I start off with room temperature chemicals, it will take several hours before it can warm up the chemicals to the correct temperature. If I start off with chemicals that are closer to the 38 degrees, the machine still takes its time to warm up the bottles once the chemicals are inside them. So far, if I want to process E6/C41 within an hour, I have to warm up the chemicals with hot water from the sink until they are ready to be used. Does anyone have a better or more efficient way to process E6/C41 that doesn't take hours?

Thanks!

[Greg]

Whatever process I am doing, way ahead of time I use a JOBO TEMPERING BOX TBE-2/12 to bring my chemistry up to temp. About an hour before processing (lots of the time way less than an hour in practice) fill up the JOBO with water at processing temp and turn the JOBO on, and also load up the Drum(s). Then when I go back down to the darkroom, I can start processing within minutes.

[tgtaylor]

Well, I have a CPA2 so this may or may not work for you:

First, I bring the tap water to about 5 degrees of the processing temperature and then fill the rinse bottles with it and then the processor with a 2L beaker leaving just enough room for the developer, fix, etc., bottles without overflowing the unit. Before turning the tap off I fill the 2L beaker with the tap water and mix the developer and the rest of the chemistry. That way everything starts off at about the same temperature. Lastly I install the tank, turn the unit on, start the proper tank rotation and bring-up the water temperature which I monitor with a Jobo color thermometer which I find to be accurate. When the water temperature in the trough reaches the proper temperature I let it run for a few minutes to verify that it is stable as recommended by Kodak and then start with the developer. At that point I usually turn the temperature dial down as it takes several minutes for any difference in the air temperature to make a difference in the processor and monitor the thermometer which always remains at the proper temperature through at least the developer which is the critical part of the process. I keep 3 plastic bottles of water frozen for the few times that I have to lower the water temperature placing a frozen bottle in the furthest slot from the heating element and placing the container in that slot (if full) in the trough.

This works for me.

Thomas

Thomas

[Willy]

Hi dede'

I have an ol' CPE-2
Our tempering volume is roughly the same....not quite 4 gallons (15L)

in close to 30 years of use, 2 hours is about the shortest time I've been able to go from a dry jobo, to beginning to process at a stable 37.7c (100f)

I use cold tap water to avoid any calcium buildup on the heating coil.

Greg and Thomas both give great advice

Another device to use as a heat source are sous vide low temperature cookers
You could put together a reliable and effective tempering box for chemicals, for about a $100
Follow suit as Greg does.

My routine is close to Thomas.
I temper my tank by rotating it dry on the processor as everything comes up to temperature.

[ic-racer]

Not sure what you are doing wrong. I have been using a CPP2 for 20 years and it is ready to go almost instantly after filling and mixing chemistry.
Are you filling the JOBO with the correct temp water? For example one degree C over indicated process temperature.
Are you mixing the chemistry with the correct temp water? For example the Arista C41 instructs 49C water mix to bring room temp concentrate to working temperature.

Usually I'll fill the Jobo and mix chemistry before loading the film holders in the drum. So the Jobo establishes exact temperature while I'm removing the film from the film holders and placing the film in the drum.

[RedSun]

Most time I use my CPE2 Plus. I have CPA/CPP, but I only use them if I want to have large print.

For CPE2, it is easy to start from scratch. I fill the basin with mixed hot/cold tap water, right to about 100F. I can even boil hot water to raise the temp quickly. During the mean time, I fill the bottles with working solutions and put them in the water.

Then I wait for about one hour to get to stable temperature. During the mean time, I load the film and finish other stuff.

I understand it is a pain to change the bath water in CPA/CPP. But I do not want to wait for 2-3 hours.

[thomas ciulei]

Hi,

i have a CPP3.
try turning off the water inlet which fills the tempering bath once your water levels are correct.
i find that the machine will always add a little cold water to the bath in case the temp sensor reads 38.1 degrees Celsius.
This will result in prolonged heating times. I save about 1/2 hour of heating time this way.

Also, try covering the area right of your drum with a plexiglass or some kind of lid, even plastic foil.
This area is very large, so there is a big heat loss there.
I also have an atl1000, where all is under a lid. That machine heats up super quick because there is virtually no heat loss.

good luck

ps- on a sidenote, always check developer temp with thermometer inside the plastic bottle.
I find that sometimes water bath temp does not equal developer temp if you are rushing stuff.

[dede95064]

Thanks for all the great suggestions! I ended up buying a Jobo TBE-2 and that's made a big difference in getting the temperature warmed up faster since there's much less water to heat than the CPP3. It almost seems like it does a better job at keeping it at the correct temperature again, probably because of the less water needed to keep it heated. I also like that I can use the smaller 600ml bottles to fill up if need be.

[Peter De Smidt]

If one can't find a Jobo TBW-2, a sous vide device should do the same thing.

[mikey1two]

I have incorporated a bucket heater to get my jobo to temp within 30min from a cold start to develop e-6.
The Sous Vide device looks promising as it has a thermostat that would shut the heater off when the temp is reached. I’m stuck pulling the bucket heater out as soon as the temp has been obtained. My bucket heater is rated at 1000W and the Sous Vide is at 800w (not much difference).
Mikey

https://www.largeformatphotography.info/forum/attachment.php?attachmentid=203481&d=1588794419

[grat]

The advantage of sous vide is that circulators typically use a hysteresis curve (probably some form of PID controller) so that as it approaches the target temperature, it backs off the power to the heating element. That way you don't get wild swings in temperature as the system chases it's own tail.

If your bucket heater does the same thing, then fair enough.

Otherwise you might be turning a little pail. ;)

[Duolab123]

I have a couple Jobo machines, I've noticed that my CPP3 has a lower overflow level. I fill my machine with 40°C water, I no longer use the solenoid valve in the machine. CPP3 requires me to fill to overflow, then I start the pump, let the upper level fill, then fill the lower until it's overflowing again. I have a TBE tempering box. I also will pour a portion of the chemistry into a beaker and warm in a dedicated microwave, I've been doing this for decades.

Easiest for me is to put slightly overheated water into the machines or the TBE, I'm really careful because HOT tap water will trip the over temperature breaker.

I run everything in manual so I can tweet temps. I can usually start up the machine, and by the time I get the film loaded it's ready to go.

[Duolab123]

I have incorporated a bucket heater to get my jobo to temp within 30min from a cold start to develop e-6.
The Sous Vide device looks promising as it has a thermostat that would shut the heater off when the temp is reached. I’m stuck pulling the bucket heater out as soon as the temp has been obtained. My bucket heater is rated at 1000W and the Sous Vide is at 800w (not much difference).
Mikey

https://www.largeformatphotography.info/forum/attachment.php?attachmentid=203481&d=1588794419

This is genius :o

[mikey1two]

My bucket heater just continues to heats up to about 160°f. The heating element in my cpp2 still functions, so once it reaches temp the machine will hold that temp on its own. The Sous Vide would be a better option if the heating element is not functional at all. At this point it’s more of a time saver.
Mikey

The advantage of sous vide is that circulators typically use a hysteresis curve (probably some form of PID controller) so that as it approaches the target temperature, it backs off the power to the heating element. That way you don't get wild swings in temperature as the system chases it's own tail.

If your bucket heater does the same thing, then fair enough.

Otherwise you might be turning a little pail. ;)

[agregov]

I never put hotter water in the Jobo than my target processing temperature. You can hear the cold water inlet activating when you do and believe that caused some pump issues with my CPP3 which required a repair. I regularly process C41 and do not have long wait times to get up to temperature. Use hotter water when you're mixing your chemistry will speed up heat time for your chemistry once the processor gets to temperature. Also, I would avoid the "automatic" mode with the CPP3 where it guides you step by step through a development process. I'd keep it on manual and agree to avoid connecting to a cold water intake. I never found any of those automatic features worked particularly well. Keep it on manual and preheat your chemistry with hot water and you're likely 90% of the way to solving your issue. The additional heating element ideas are interesting but with a CPP3 class machine, they absolutely should not be necessary for a efficient workflow. If you're still having issues, you might reach out to Omar at Catlabs because maybe there's a mechanical issue with your machine.

[Duolab123]

I don't put "Hot" water in. I have thermostatic mixing valves in my darkroom. I fill the unit at 4° or 5° F above the target temperature. This just warms up the plastic and pump etc of the processor.

Unless you have a chiller and circulation circuit hooked up to the Jobo solenoid valve I have found it to be of little value. Same goes for the older CPP2.

Chillers used to be standard equipment with big darkroom sinks especially in industrial settings for graphic arts.

If you lower the set temperature of the processor below the actual bath temperature, the solenoid valve will be energized, if you don't have COLD water at the valve the temperature can actually rise out of range, especially with black and white.

These machines are great, but experience and following the instructions (somewhat sparse instruction pamphlet ) works.

[Drew Wiley]

Never use a tempering box as a quick heater or you risk damaging it. It's meant to sustain temperature. You want to start with water in it just slightly below your specified temp, and then if necessary, ratchet up the heat bit by bit, rather than all at once. If the ambient air is too hot, the opposite direction, then just dunk one of those little frozen "blue ice" paks in there to offset the extra heat, but not in direct proximity to the heater element. Recirculating thermoregulators way more precise than anything Jobo offers are available from scientific suppiers, and for around the same price range as good photolab equivalents were - roughly a thousand bucks apiece. But they can also be a fussy headache in certain ways, so if you don't need extremely tight temp tolerances, a tempering box is more realistic. Then there are automated mixing valves like Intellifaucet that can provide mixed hot/cold water at a certain temp. Many of us have used those too at one point or another. A used lab supply that handles Kreonite etc might have something like that at a discount price.