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.

86010

[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-Jobo-04042-Duo-Clip-NEW-reel-separator-clips-FREE-SHIPPING-WORLDWIDE-/271088028583?pt=LH_DefaultDomain_0&hash=item3f1e1b0ba7

[Jim Andrada]

Thanks for the suggestions - I was thinking of taping the rolls together but wasn't sure it would hold during processing.

By the way, is there any reason a second extension couldn't be used to process 8 or so rolls at once? (And I ordered a set of the clips - thanks for the link)

[Sevo]

Thanks for the suggestions - I was thinking of taping the rolls together but wasn't sure it would hold during processing.

It will depend on the tape - but the majority of films ever developed will have been adhesive tape chained, as that has been the standard procedure on high volume continuous processors ever since they went off heat weld and wet splicing. Just make sure the tape is not water soluble and the area is big enough that water creep into the gelatin does not break the bond during the processing.



By the way, is there any reason a second extension couldn't be used to process 8 or so rolls at once? (And I ordered a set of the clips - thanks for the link)

As long as you don't exceed the weight limits of the lift or length of the processor, your only concern would be the delay in filling and the effect it might have on the difference between inner vs. outer film processing times. But whether that matters will depend on the process and temperature.

[koh303]

As long as you don't exceed the weight limits of the lift or length of the processor, your only concern would be the delay in filling and the effect it might have on the difference between inner vs. outer film processing times. But whether that matters will depend on the process and temperature.

The Jobo lift is deisigned to introduce the chemistry while the drum is rotating, thus creating a near instantaneous introduction of all the film in a said tank to the chemistry. Jobo once offered a multitank 12, which could hold up to 12 rolls of 35 or 16 rolls of 120, for use on larger ATL machines. Either way, the time difference between the inside and outside loaded rolls on each reel would be meaningless as the entire induction of chemistry would take less then 20 seconds. Unless you are running some super short BW dev, you will not see any difference, and even then i think you will be hard pressed to see any chance, as the drum rotates splashing the chemistry all around inside the tank.

The only limit, would be as noted, the physical size constraint, along with the max safe load capacity of the motor (differs for each machine).

[Jim Andrada]

The lift has never inspired me with it's "robust" design - every time I use it I half expect it to break, but so far it hasn't. Just in case I always put a finger underneath and help it up a bit to take some of the weight off the lift arm. I suspect it won't be an issue with the few ounces of extra weight going from 6 rolls to 8 or so.

I've been using the Tetenal c-41 chems and they seem to work well for me. I do wonder though why they say to not run the stabilizer in the processor. I don't, but just not sure why they recommend against it.

[koh303]

Wetting agents, in this case the tetenal stab bath, clings to the reels, and is somewhat hard to clean off 100%, so they say you should never use it the tanks. The stab also leaves a thin absorbent layer of goo on the reels, which will eventually stain the reel which can in some cases lead to chemical cross contamination.

The Jobo lift instructions call for the user to support the lift with his spare arm as it is being raised. That said, if used carefully and with some thought will last for ever.

An assist handle might make it feel a bit more solid.

[ic-racer]

Thanks for the suggestions - I was thinking of taping the rolls together but wasn't sure it would hold during processing.

By the way, is there any reason a second extension couldn't be used to process 8 or so rolls at once? (And I ordered a set of the clips - thanks for the link)
You can do 10 rolls of 120 in a CPP2 with the 1500 drums. With t-max developer that comes in just under 1000ml of chemistry.

[alexn]

Good that you ordered some of those clips... I will say this.. Take care.. Even with those clips, I have overlapped films.. Its not impossible to do. Just make sure when you get the first roll in, that it is the whole way onto the reel, as far as you can make it go... I have only done it 3 times in the maybe, 200 times I've loaded rolls onto my reels, but two of those times they were critical images that were lost...

[Jim Andrada]

I'm thinking that when I load the reels I'l be sure the first roll is in all the way, insert the clip, and stop feeding the second roll as soon as the end is just into the grooves.

Re the stabilizer contaminating the reels and tanks, I can use a different tank for stabilizing, but don't see a good way to avoid getting stabilizer onto the reles themselves so I guess I'll just have to pretend I'm back in Organic Chem lab and clean the H out of everything. It would seem that there must be some cleaning agent that would get the stabilizer off the reels but I can't think what it would be (Chem lab was more than 50 years ago!)

[koh303]

Fill a 2 liter or larger jug\beaker with stab\wetting agent.
Hold the reels over the jug, and rotate the two halves counter clockwise to unlock the two halves, separate and let the roll drop softly into the stab bath.
Let sit for as long as kit requires, then hang dry, easy.

No need to drop the reels in.

[Ari]

I've been using the stabilizer with my reels for a long time, and never noticed anything amiss.

[ic-racer]

Just make sure when you get the first roll in, that it is the whole way onto the reel, as far as you can make it go...

When I push the red clip in I always check that the film end still 'bounces' when I touch it with my finger. If it is caught by the red clip you can tell. In which case lift the red clip and advance the film more. Usually the film stops not quite at the end and it needs just a little extra twisting of the reels to make that last few inches.