Possibly a stupid question on pre-soaking in Jobo.

[Lachlan 717]

Historically, I have pre-soaked when using Jobo tanks by filling them to the brim.

This is fine for, say, a roll or two of 120, or even a Multi Tank for 4x5.

Where it gets difficult is when I'm using a 3063 with 3 sheets of 7x17 in it. That's not only a heap of water, I'm worried that the back pressure "gurgle" could knock the sheets from the seemingly small ridges that hold them in place.

So, my hopefully not-too-stupid question is, can I do a pre-soak on the machine by pouring water into the tank in situ (obviously, whilst it's spinning)?

Thanks,

[Jon Wilson]

Historically, I have pre-soaked when using Jobo tanks by filling them to the brim.

This is fine for, say, a roll or two of 120, or even a Multi Tank for 4x5.

Where it gets difficult is when I'm using a 3063 with 3 sheets of 7x17 in it. That's not only a heap of water, I'm worried that the back pressure "gurgle" could knock the sheets from the seemingly small ridges that hold them in place.

So, my hopefully not-too-stupid question is, can I do a pre-soak on the machine by pouring water into the tank in situ (obviously, whilst it's spinning)?

Thanks,

I have pre-soaked my film ever since I started using the JOBO tanks several years ago. I put 50ml of water per 4x5 sheet, 80ml for 5x7, and 100 ml for 8x10. As long as you don't exceed 1000ml in the 3063 tank, that should be fine for 3 sheets of 7x17. It would seem that if you use the same amount of water to pre-soak as you use developer for your 3 sheets of 7x17, that should do fine without stressing the motor. IIRC, the max solution in the larger drums is 1000ml and anymore can stress the motors, especially the older ones. I am sure others with more knowledge than I do will respond too.

[Oren Grad]

That will certainly get the emulsion good and wet. As for whether adding the extra step will increase the odds that one or more of the sheets will slip out from between the ridges, my own experience with the 3062 and 3063 suggests that it will. But I think you'll just have to try it and see; results could conceivably vary based on small differences in cut sheet sizes or in our respective techniques for squeezing the film into the spaces around the drum.

FWIW, I don't pre-soak, either with ULF in the 3062/3063 or with smaller sheets in the 3004/3005/3006/3010.

[Lachlan 717]

Thanks for the advice.

I also do single sheets in a 28xx drum with extension. It seems to me that this tank holds the film in more firmly than the 3063. Perhaps it's the tighter circumference…

[John Powers]

Thanks for the advice.

I also do single sheets in a 28xx drum with extension. It seems to me that this tank holds the film in more firmly than the 3063. Perhaps it's the tighter circumference…

I have run two sheets of 7x17 "in a 28xx drum with extension" for 5-6 years. Of the several hundred sheets run, I have never (knock on wood) had one fall out.

What developer are you using? I have always read that with pyro in a 3062 or 3063 tank people have gotten marks where the small ribs touch the negative. You can't see the marks on the negative, but they show on the print. I tried it once and got marks. I have not tried again. I use Rollo Pyro developer from Bostick & Sullivan and Kentmere Fineprint VCFB with Ilford Multigrade developer.

I would prefer to develop three at a time in a 3062 if I could resolve this problem. Have you been successful or do you not use pyro?

Thanks,

John

[Lachlan 717]

I have run two sheets of 7x17 "in a 28xx drum with extension" for 5-6 years. Of the several hundred sheets run, I have never (knock on wood) had one fall out.

What developer are you using? I have always read that with pyro in a 3062 or 3063 tank people have gotten marks where the small ribs touch the negative. You can't see the marks on the negative, but they show on the print. I tried it once and got marks. I have not tried again. I use Rollo Pyro developer from Bostick & Sullivan and Kentmere Fineprint VCFB with Ilford Multigrade developer.

I would prefer to develop three at a time in a 3062 if I could resolve this problem. Have you been successful or do you not use pyro?

Thanks,

John

Thanks, John.

I've tried Pyro MC, but I think that the batch I received from PF wasn't the best.

The liquid developer I get in Australia is Tetenal UltraFin. I really like it. Very easy to use as a 1:20 one-shot, fine with constant agitation, and I seem to get really good negs with it. I really haven't run enough sheets through yet, but I hope to get stuck in to some soon. I also have a 3063 that I got for $40 that is begging to be tried.

I have found that it's quite easy to scan'n'stitch 7x17 on a V700, though!

Back to the original question, though: do you presoak via rotation?

Thanks,

[polyglot]

You normally presoak in a Jobo by adding the same amount of water as you would developer (i.e. more than enough to cover, less than 1L) and running it for 5 minutes. That will cover/soak the film quite well, just like it does with developer.

If you're doing a process that requires tight temp control (e.g colour), then you probably want to use at least 2 changes of water, both at process temp.

[John Powers]

Back to the original question, though: do you presoak via rotation?

Thanks,

The Rollo Pyro kit from Bostick & Sullivan comes with:

500ml of part A
1000ml of part B
75 gm of sodium metaborate

I start the process with a five minute soak rotation using 1/4 teaspoon or 0.75 grams of sodium metaborate in 500ml of water. I have a well as my water source, so I filter the water. I use #4 rotation speed for the whole process. A little research here and you will read that there is much difference of opinion on the correct rotation speed.

John

[Lachlan 717]

Thanks for your thoughts, John.

I've been using a Jobo CPA for quite a while (just replaced it with a brand new CPP), so have the speed down pretty well for my process.

It's just the thought of so much water being used if I fill the tank, rather than using it rotationally.