Tank compatibility for Jobo CPE2

ac123

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Hi,
I recently acquired a Jobo CPE2 (non-plus) which I am hoping to use for processing chemicals for RA4 printing.
Unfortunately there is no tank so I need to acquire one. I'll be mainly printing 8x10 and so was looking at the Jobo 2830.
Would this be compatible/fit with the CPE2 motor system?
Thanks in advance!
 

koraks

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I've run an 2800 on occasion on my CPE2. Works OK, but you need to to use the supporting rollers (the little black bar with the two white wheels on it) as otherwise the magnet won't hold this tank.

Also keep in mind you need the regular lid with the rubber cap and not the cogged one unless you have a lift, as @mshchem also hints at.
 

mshchem

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And a tank magnet.
 

koraks

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Don_ih said:
Does that mean you use tanks on your Jobo without using support rollers?
Click to expand...

No, certainly not! Sorry to be unclear; I meant to say that the support rollers are absolutely crucial in this setup.
And I don't use them at all at the moment. I've done it on occasion, in the past, but presently I wouldn't even know where my single remaining 2830 drum is.
 
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ac123

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mshchem said:
And a tank magnet.
Click to expand...


Copy that, thanks - unfortunately no lift on this machine.

So I would need a rubber Inversion Lid like this one, that would theoretically be compatible with the 2830?

Would I also need to obtain a tank magnet? Is this something that is attached to the Jobo or the Tank?
 

koraks

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ac123 said:
So I would need a rubber Inversion Lid like this one
Click to expand...

Yes, and the cap that goes with it. There are two caps for these Jobo tanks; one with the cogs, and one with a rim on which you can put the lid you linked to.

Usually it makes more sense to look for a drum with a magnet and the right type of cap for your use than to buy a drum and then hunt down the accessories. You generally end up paying a lot more that way.
 
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ac123

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Thanks!

This here would be the lid and cap you're referring to?

That makes sense- I'll keep an eye out. Ideally I would be looking for a full tank setup that looks like this one ? (Except specifically larger than 10" so that I am able to process 8x10s)

Should I assume all jobo tanks/cap setups to have this magnet?
 

mshchem

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The lid you've shown is for the smaller diameter 1500 series tank. I would suggest you get in touch with Catlabs. They may have a used 2830 tank and magnet. The tank needs the correct lid and a cup inside not the funnel.
Here's a picture from Catlabs. Last I checked Jobo doesn't make print tanks.

USED Jobo 2830, 2840, AND 2850 Film/Print drum for sheets up to 16X20, 8.5x11 with cog lid

2830 USED: good working condition Generic photos - Labels vary, fill quantity data available online • for film or prints up to 8.5X11 • Inversion...
www.catlabs.info

Again you need ordinary cap with the inside cup.
 
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ac123

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Thank you for this info!
Catlabs did have the tank/magnet I needed and was able to obtain from them.
 
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ac123

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Question for any Jobo bath users - is it OK to use this machine to warm the temperature of the water from room temp (around 70 deg F) to the 84 deg F that I usually print at?

I was under the assumption from something that I read online that you should only use this machine to raise the water temperature at max 3-4 deg F, and that anything more than that would damage it in the longterm.

However I was just reading the manual, and it seems to encourage using this machine to heat up from room temperature over the span of 1-2 hours? If so, this would save a lot of time as I could leave it filled with water overnight rather than having to dump it out and refill with new hot water before the start of every session.
 

koraks

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ac123 said:
you should only use this machine to raise the water temperature at max 3-4 deg F, and that anything more than that would damage it in the longterm.
Click to expand...

I don't see how this would be harmful in any way.
I do know that Jobo manuals tend to warn against filling the machine with pre-warmed water. Supposedly because of the risk of people dumping boiling water into the machine and then mixing some cold into it to speed things up. Full disclosure: when I use my CPE2, I usually fill it partly with cold water from the tap and then dump some boiling water into it that I allow to mix with the cold. Guess what...works fine. Of course, "not recommended" and "no liability accepted".

ac123 said:
this would save a lot of time as I could leave it filled with water overnight rather than having to dump it out and refill with new hot water before the start of every session.
Click to expand...

Yes, sort of; the problem if you leave water in it for extended periods of time is that you tend to get bacterial and algal growth in there. It's kind of yuckie. It won't happen overnight though, so if you use the machine today and then use it again tomorrow, and then drain it, this should be perfectly fine.
 

Don_ih

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ac123 said:
I could leave it filled with water overnight
Click to expand...

I noticed the room would get pretty steamy after the Jobo had been heating it's tub of water for a few hours. I don't think I'd want it maintaining temperature all night. Water above room temperature readily evaporates. Not as quickly as boiling water does but I bet you'd still need to add a few cups in the morning if you had it on overnight.
 
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ac123

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Yes, thinking I would turn the machine off overnight, and turn back on in the morning to heat the room temp water back up to working temp


This just eliminates having to dump/refill the tank directly every session since I don't have the Lift.
 

grahamp

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The Jobo processors were designed to run at 38C if needed (for C-41). My CPE2+ is rated at 330 Watts for the heater (360 Watts overall), so you should be able to use an outlet timer to bring it up to temperature ahead of planned use. The risk with doing automation is that you can forget to turn it off, and it dries out with the heater on.
 

koraks

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Don_ih said:
I bet you'd still need to add a few cups in the morning if you had it on overnight.
Click to expand...

grahamp said:
it dries out with the heater on.
Click to expand...

It has a thermostat, so it'll keep the bath on whatever temperature you set it to. If you mistakenly leave it on, it'll mean you have a tub of let's say 38C water sitting around. How long it'll take before 5 gallons (or whatever the capacity of the tub is) will evaporate under normal room vapor pressure I wouldn't want to begin to calculate, but I am quite sure it'll take many days at the very least, and likely several weeks.

Things won't get out of hand as quickly as you guys fear. I've had my Jobo on during the (entire) day several times and for several hours pretty much routinely. It won't run dry overnight and not over the course of a couple of nights either. It's a tempered bath, not a steam generator.
 

Don_ih

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Yes, and I've run mine for a full day and it made the room quite humid - and quite a bit warmer, also. Having a large open tub of water at 38 degrees do that to a room that's normally around 17. It's not a "fear". I'm suggesting it's not a great idea to needlessly humidify your darkroom to that extent.
 

koraks

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Don_ih said:
I'm suggesting it's not a great idea to needlessly humidify your darkroom to that extent.
Click to expand...

It's not a great idea to work extended periods of time in a room that has so little ventilation that running a single Jobo will effectively humidify it. Just your breath alone will raise RH more than a single Jobo, so if the Jobo is a problem, then the root cause of the problem is much more severe.

It's wasteful in power of course.
 

Sirius Glass

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The supporting rollers are a must. I use a cog to connect the drum, not the magnet. I use the lift, but the bar was broken off when I received it, so I left the tank by hand.
 
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