120 film in Jobo

[Jim Andrada]

I've been using my Jobo CPP-2 w lift for sheet film only but would like to try roll film. When I got it it also had a set of reels and a 1520/1530 tank combination. There was also a plastic core that would fit the 1520 but no extension for the combined 1520/30. The clips that I believe are supposed to prevent two 120 rolls overlapping each other are not there and it isn't clear if there would be any way to use them if they were - the set I have might be fairly old.

Questions:

What is the function of the extension core and is it really necessary? (I suspect it's to keep the reels from slipping relative to the tank - is this correct?)

Is there much risk of the film overlapping if the clips are not used to separate the rolls.

Any other comments on the use of the system wold be helpful - particularly re loading film into the reels. Probably better to sacrifice a blank roll for practice than to sacrifice a roll with photos!

[Fred L]

Can't speak to the plastic reels as I use the metal Hewes reels for 35 and 120. The centre core is supposed to slip over the bottom of the lid's funnel intake. If it doesn't, you chance light leaks through the pour hole. Probably unlikely but I wouldn't rule it out.

Secondly, the fit between the lid and core should be such that the core should be snug against the bottom of the tank. If not, the bottom of the core won't engage the stops (I'll call them that) ,which keep the core locked and from rotating inside the tank.

[Larry Gebhardt]

I've never used the 1500 series tanks. But in the 2500 series tanks you need to core. Otherwise you will ruin your film from light leaks. The 2500 have a tab to prevent the film form overlapping. I imagine you need the clips.

[Jim Andrada]

Thanks guys! I've found a couple of cores online but they seem to come with the extension tank which I already have:<((

[ic-racer]

The cores form a light trap for daylight processing. The red plastic 'stoppers' are needed when doing 2 rolls of film (120, 35mm or 16mm) on a single reel, I think you can get new ones here: http://processorparts.blogspot.com/ or maybe from Greg Blank or ebay.

[Steve Barber]

Also, the core allows an efficient means of washing the film with the use of a "cascade" to direct water down to the bottom of the tank to return up through the reels along the exposed emulsion and be exhausted through the lid while the lid remains on the tank.

[Ari]

The clips are important when loading two 120 reels; if you can find a pair, get them.
If not, practice loading in daylight, and learn to "feel" when the reel is loaded properly; it can be somewhat tricky not to cause any overlap.

[richardman]

To load two rolls, you can also just tape the ends together. It works best if you carefully remove tape from the first roll when it's mostly in, and then tape the beginning of the new roll (obviously carefully by touch only of course)

[Ari]

To load two rolls, you can also just tape the ends together. It works best if you carefully remove tape from the first roll when it's mostly in, and then tape the beginning of the new roll (obviously carefully by touch only of course)

Excellent solution if you don't have clips.

[Ari]

Found these, if you're interested:
http://www.ebay.com/itm/LOT-of-3-Job...item3f1e1b0ba7