Help Identifying JOBO Tank.

[jzeairs]

ok so i recently acquired this jobo tank. it holds two 4x5 reels. i can not find and identifying marks on it. i am curious as to what kind of tank it is and how much developer i should add to process it in a roller. any info would be appreciated.

[Leigh]

I think I have the same tank, with two 2021 reels for 4x5 film (not adjustable).

Mine says RO-Tank 4323. The label shows various film sizes from 110 through 4"x5", all taking 950ml.

- Leigh

[jzeairs]

ok cool. do you develop by roller or by inversion?

[Leigh]

I've never used it.

It has a magnet on the bottom, so it would work on the non-lift machines (CPE/CPA).

Since the lid is water-tight, you could also do inversion, but that might result in uneven agitation.

- Leigh

[jzeairs]

Ok. Mine has the magnet bottom. I have a uni color roller that I was going to use with it. I've heard that your supposed to have your development times over 10 min when using a drum. Any truth to this?

[Leigh]

I would think longer times would be better. I've never heard a specific number.

- Leigh

[polyglot]

Ok. Mine has the magnet bottom. I have a uni color roller that I was going to use with it. I've heard that your supposed to have your development times over 10 min when using a drum. Any truth to this?

None whatsoever, especially if you presoak to avoid unevenness from how the developer hits the film.

[jzeairs]

ok cool. so pre soak and normal development and i will be fine. also how much developer do i need to put in the tank if i am using the roller? enough so when it is laying on its side it is half full?

[Leigh]

how much developer do i need to put in the tank if i am using the roller?

The amount of solution required is 950ml, as I stated in post #2 above. This applies to all solutions (pre-soak, developer, stop, fix, etc).

The actual amount of developer required depends on the dilution being used, the remainder being water.

- Leigh

[Chuck Pere]

My system box says 32oz for rotary and 68oz for inversion. My tanks are not marked but the box says 4323. Reels are marked 2021. I've used these tanks for 4x5 for many years. My own unscientific, and not recommended for anyone else, method is to use one reel loaded with 4 sheets, 1500ml of PMK and inversion agitation of 60s to start and once every 15 sec after. Good exercise turning that big tank.