Rodinal in a Jobo

[Ed Sukach]

Anoter thing - I found those "Footnotes" referred to in the JOBO text above:

The CPE-2 and CPE-2 Plus should not be used with more than 600 ml of solution. Excess volumes will limit the useful life of the rotation motor.
The CPA-2 and CPP-2 processors should not be used with more than 1000 ml of solution. Excess volumes will limit the useful life of the rotation motor.

I wonder if you could be a little more specific as to the location of these "footnotes". The only "maximums" I've found on the JOBO web site referred to the 3000 series tanks --- specifying, No more than 1000 ml in the CPA, and no more than 1500 ml when using the 3000 series tanks in the CPP2.

It does recommend caution in the use of the heavily loaded tanks ... something I do as a matter of course anyway. I simply manually assist in raising the tank by lifting the tank carrier in addition to using the lifting lever.

 

[Denis P.]

I wonder if you could be a little more specific as to the location of these "footnotes". .

Ed, try here:

http://www.jobo.com/jobo_service/us...nstructions_misc_tank_and_drum_capacities.htm


Scroll down to heading "Never use a tank or drum loading that exceeds the processor's specifications". There's a link to bottom of the page, more specifically:

http://www.jobo.com/jobo_service/us...s_misc_tank_and_drum_capacities.htm#Footnotes

I'm not trying to split hairs here, just trying to explain why JOBO might have warned against too dilute chemistry in drums - like I said, you're facing either developer (or fixer, or whatever) exhaustion, or you're nearing the upper limit of the quantity recommended for a particular drum/tank.

Regards,

Denis

 

[Ed Sukach]

Originally posted by Denis P.
...
b) you make Rodinal 1:100, providing enough "soup" to be sure the developing agent won't exhaust as in a) above, but then you are probably pouring too much liquid into the drum, and are running the risk of damaging the processor! (Remember that JOBO always states the MIN and MAX quantities of chemicals to be used in each particular drum!). JOBO processors have plastic gears, and the lift (particulalry the handle) are relatively fragile, so if you pour in too much liquid in the drum, you're simply asking for trouble! The drum is simply too heavy for tha processor...

and ...

... Scroll down to heading "Never use a tank or drum loading that exceeds the processor's specifications". There's a link to bottom of the page, more specifically:
http://www.jobo.com/jobo_service/us...s_misc_tank_and_drum_capacities.htm#Footnotes
I'm not trying to split hairs here, just trying to explain why JOBO might have warned against too dilute chemistry in drums - like I said, you're facing either developer (or fixer, or whatever) exhaustion, or you're nearing the upper limit of the quantity recommended for a particular drum/tank.

Ah... it is often good to get to the source of the confusion..

In the first quote, you had specified "DRUM" capacities (emphases above are mine). JOBO states PROCESSOR capacities - irrespective of drum types/ configurations. I had NEVER seen information limiting the maximum capacities of the individual DRUMS ... so began the discussion.

Be that as it may, I've been considering the "load" involved: rotating (and reversing rotation) inertia. This could getcomplicated, considering that the liquid in the tank would probably continue in its rotational movement for some time, only reversing when the friction (liquid) with the tank exceeded equilibrium...

Shades of a Mechanical Engineering exercise!! --- and dim, distant, memories...

Are you there, Ole? Want to tackle this one?

 

[Clueless]

Couldn't the whole concern be circumvented by simply going to a second unit of fresh dilluted developer that "follows" the first drum-full half way through the development time? You'd get your dillution and not strain your Jobo.