Jobo 2509n & C41

[miha]

I'm about to purchase a Jobo 2500 drum, a 2509n sheet film reel and their manual roller base to be able to home process C41. Here is the question: can the roller be operated in a water bath in a deep enogh tray so that a quater or so of the drum is kept under the water level. I have a dish warmer from Kaiser: http://www.kaiser-fototechnik.de/en/produkte/2_1_produktanzeige.asp?nr=4141 which will heat the tray. Should I skip the roller altogether and agitate as I do with B&W films?

Thanks.

 

[DanielStone]

I've never used the manual roller base, but have done C-41 on a Jobo processor many times w/o any issues.
If you use the rotary method, you'll use much less chemistry than w/ inversion processing. MUCH less. This will allow you to stretch your chemistry more, saving you some money in the long run.

Make sure that you're well stabilized temperature-wise when using the Kaiser hotplate. Unless specific degree markers are marked(and read true), you might want to take a day to head up a tray SLOWLY, allowing the water temp to stabilize after each adjustment. When you reach a WATER BATH TEMPERATURE of 100-102˚F, make a mark on the adjustment dial so you'll have it for next time . Also, are you using a METAL tray? I'm asking because a plastic tray won't transfer the heat to the water like a metal one will.

I believe you can get great results using manual agitation and the Kaiser hotplate. But take the time to set up your system, and keep good notes on color chemistry usage.

cheers,
Dan

 

[miha]

Hi Daniel, yes I was thinking of getting a metal tray due to conductivity. What I'm not sure about is how fast should I roll the drum.

 

[DanielStone]

I'd work on keeping a 2-3seconds per rotation schedule. Not too slow, but not too fast either.
Forward and backward, both ways. Don't ask me why I recommend this

-Dan

 

[miha]

Thanks, 2-3s per rotation seems fine and not too exhausting for the operator

 

[CatLABS]

Miha,

You only need 1-2 inches of water (to make good contact with the drum) to maintain the dev temp for C41.
If the water level is too high the tank will float (unless you have more liquid inside of it then outside), though for the multitank 5, it might just balance at the above mention height.

The multitank 2 might be too small to do this with it floating off the roller all the time, unless the water level in your tray is 2-3cm, max.

Either way it should not be a problem.

Reversing the direction does not matter that much, but does not hurt either. You want to be at 50 -65 RPM or so in speed.

Good luck!