Jobo 2523 Tank Volume

[rshepard]

I just bought a couple of Jobo 2500-series tanks on eBay. The 2523 (holds one reel adjusted for 120 roll film) has the volumes 270/560 ml printed on it. But, the Jobo web site's sheet on the series says that the capacity for a single roll of 120 film is 170 ml, and 270 ml for two rolls of 120 or a single roll of 220.

Does anyone know why the tank itself shows volumes twice what the spec sheet shows?

Thanks,

Rich

 

[Denis P.]

My guess is that the lower volumes listed are for rotary (machine) processing, while higher volumes are for "traditional" processing (hand inversion, etc.).
OTOH, you might be referring to quantities required for ONE film, as opposed to TWO films - you know that you can load two films on one reel, right? So, if you have one film on the reel, it is closer to the edges of the reel, and lower volumes are required - if you load two films, they will go all the way to the center of the reel, thus requiring more chemistry to cover them both when the tank is rolling (horizontally) on the processor.

Does that make any sense?

Regards,

Denis

PS: if the 2523 is too small for your requirements, I'll gladly take it off your hands

 

[Paul Sorensen]

My understanding is that the numbers are for rotary processing. Since you load the film from the outside, a single roll of 120 won't go as far toward the center as two rolls or a roll of 220. That means that it will take less solution to cover the film adequately when the tank is laid on its side. I have never used mine with 120 film, so I am only guessing, but that's my guess.

I don't really know what the 560 ml is in reference to, perhaps that is the amount that it will hold before the solution starts spilling out the top when it is rotated.

Paul.

 

[Huub S]

Neighter do i know what the 560 ml means. The table on my tank states that you need 170 ml for one 120 film and 270 ml for a 220 or two 120 films. Mine has also a second table that shows the volumes needed for inversion processing. For 120 and 220 it's 900 ml.

Huub

 

[Nick Zentena]

Is it an older tank? If it is the higher number is for inversion. Sounds about right. At some point they stopped even mentioning using 2500 tanks for inversion.

 

[rshepard]

Thanks, all. I should have mentioned in my original post that the tank itself does not mention hand-processing, only rotation (in English and German), followed by the two volumes. That's what threw me.

Yes, the smaller volume is for a full load (2 135 strips, 2 120 rolls, or 1 220 roll), but the larger volume ...? Strange.

I'm going to give the tank a test drive this morning with some film-speed test rolls. I see that the 2502 reel has a built-in stop to prevent a single roll of 120 winding in too far, but I need to look more closely to see how to open it so I can load two rolls on the same reel.

I appreciate your responses. Perhaps it is an old tank, but as long as it works, who cares, eh?

Rich

 

[Nick Zentena]

My oldest tank reads something like:

Rotation : Small number / big number.

The big number is way too big for rotary use. The tank would burn out the motor on a Jobo. You can check if the bigger number is for inversion pretty easy. Put the empty reel in and pour 560ml of water in. If it covers the reel you'll know.

Just flip the red thing up. Load the first roll all the way then push it down. That's all.