RA-4 Developer & BLIX Replenished Tank Life

RellikJM · Aug 11, 2008

I am using a moduline slot processor that holds 3785mL of each solution and I'm processing 14 8"x10" sheets at time. Last night after processing 52 8"x10" sheets I replenished 20mL per sheet for both developer and BLIX and an extra 200ml to make up for loss. Total replenishment volume was 1240ml. I removed 1040mL from each 3785mL of solution and added back 1240mL.

First: Am I on the right track for replenishment?

Two: I know that the 3785mL should be good for 60 8"x10" sheets non replenished. Is the replenished solution now good for another 60 8"x10" sheets?

Thank you for any help!

Photo Engineer · Aug 11, 2008

Kodak's web site gives 16 8x10 sheets per liter. Even that seems high to me. Your figures are way beyond that. It does not sound good to me. I use not more than 8 sheets / liter, non-replenished. Above that and I replenish.

PE

RellikJM · Aug 11, 2008

Photo Engineer said:
Kodak's web site gives 16 8x10 sheets per liter. Even that seems high to me. Your figures are way beyond that. It does not sound good to me. I use not more than 8 sheets / liter, non-replenished. Above that and I replenish.

PE

I'm using the replenshment rates listed in Kodak's RA-4 Manual under roller transport processors. I can't see whether I lift the prints out or a roller moves the print to another tank makes any kind of difference in replenishment rates.

16 per Liter works out to 62.5mL per 8"x10". I'm not getting any bad effects by using the 60mL per 8"x10". Is there something that is going to happen to my prints after some time after they are processed e.g. fade, color shift?

Photo Engineer · Aug 11, 2008

Your process is ok. I misread your OP, sorry. The fix (part of the blix) and wash rate will determine image stability more than anything else. If you wish, you can run a standard silver and hypo test on a blank sheet of paper to see if the fix and wash are going well.

PE

RellikJM · Aug 11, 2008

Photo Engineer said:
Your process is ok. I misread your OP, sorry. The fix (part of the blix) and wash rate will determine image stability more than anything else. If you wish, you can run a standard silver and hypo test on a blank sheet of paper to see if the fix and wash are going well.

PE

Forgive my ignorance :confused: but how do I run the "a standard silver and hypo test on a blank sheet of paper" ?

Photo Engineer · Aug 11, 2008

Process an unexposed sheet in your machine, or use a clear white piece of the paper that has been processed and after it is processed properly according to your methods, use the standard test solutions for retained silver (sodium sulfide solution) and retained hypo (silver nitrate in acetic acid). They give colored stains if the paper is not washed or fixed properly. These solutions are available from most photo suppliers and there is a long series of threads on this here on APUG.

PE

PHOTOTONE · Aug 18, 2008

I have found that the blix oxidizes from sitting in the processor, regardless of use, or rather non-use. I think one should consider mixed up Blix as having a rather short tank life if used infrequently, which improves with frequent daily use and replenishment. Replenishment rates do not take into account low usage.

frotog · Aug 18, 2008

PHOTOTONE said:
I have found that the blix oxidizes from sitting in the processor, regardless of use, or rather non-use. I think one should consider mixed up Blix as having a rather short tank life if used infrequently, which improves with frequent daily use and replenishment. Replenishment rates do not take into account low usage.

I have found that adding kodak blix additive to your replenisher alleviates this problem. Unfortunately it is only available by the case from minilab supplies.

Photo Engineer · Aug 18, 2008

The blix is a mixture of an oxidant and a reductant (Ammonium Ferric EDTA and Ammonium Hypo). Eventually they self destruct.

PE

frotog · Aug 19, 2008

How does the blix additive work?

Photo Engineer · Aug 19, 2008

IDK. That is new. I would have to do some research on it.

PE

Photo Engineer · Aug 19, 2008

Done looking. The only thing I can guess, without looking at the MSDS, are from my own notes.

The life of a bleach or blix with Ferric EDTA or Ferric NTA can be extended by use of extra sulfite and EDTA or NTA depending on the complexing agent. The other way to extend a bleach is via oxidation, but this depletes sulfite and hypo. So a blix regenerator can be two parts. A mild oxidant and then sulfite EDTA. That is about all I can find. The amounts would have to be very carefully tuned to prevent destruction of the blix or bleach.

PE

frotog · Aug 19, 2008

Photo Engineer said:
The amounts would have to be very carefully tuned to prevent destruction of the blix or bleach.

PE

Thanks Pe! That explains why you're only supposed to add it to the replenisher (20ml/litre if I remember correctly)....anyhow, it works for me and makes a big difference in the lifespan of the working bath, especially with small tanks where excessive oxidation is oftentimes a problem.

RA-4 Developer & BLIX Replenished Tank Life

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