Bleach Recovery Process in SSK-8R

[NortheastPhotographic]

Hi! i have some questions about the bleach recovery process in my SSK-8R for greatest economy...

So here is my understanding how of it's supposed to work...

You process you film and set the SSK-8R to save bleach. After the bleach stage the SSK-8R dumps to a SEPARATE "old bleach" bottle, which has a dump tube, and a suction tube. You then program a replenishment ratio of old/new bleach and the SSK-8R mixes them together on the next batch.

(Meanwhile I imagine I'm theoretically topping off the new bleach? I have a 5L bottle that I'm going to mix my bleach in. Of course Bleach Replenisher A & B make 10L, so I'm going to mix half quantity for this. If I want to top off I suppose I should just mix it all into 2gal of solution, and keep the 2nd gal separate for topping off the main feeding bottle to the SSK-8R...)

Here's where I'm confused.... Many of this site have indicated that bleach essentially lasts indefinitely. With aeration I should be able to get months if not years out of it. So why separate the old/new bleach? Why not just dump the used bleach back into the main feeding bottle, and just make sure to keep aerating regularly? Is that possible or am I missing something here...

Also, is there any truth to the idea that the bleach starter isn't necessary? I forgot to purchase some from Unique Photo and would rather simply not haha.

 

[EdSawyer]

Here's what I do with my SSK4. I have a separate bottle for used bleach. I don't top off the main bottle, and I save the used bleach in the second bottle. When main bottle is empty and the used bottle is full, I add bleach regenerator, aerate it all, and then that becomes that main bottle. I would recommend using bleach starter especially for your first batch of new bleach. That's the only time I used it, after that I used bleach regenerator to regenerate the used bleach and use it another time. I have used regenerated bleach For multiple runs, I think I did about 400 or 500 rolls on one 5 L bottle, regenerating it about eight times. It was still going strong, but I'm dumped it anyway just to be safe. Plus I had plenty of new bleach anyway (I bought the huge quantity containers of it) so it didn't hurt toss some

 

[Mr Bill]

Many of this site have indicated that bleach essentially lasts indefinitely.

Hi, this is not exactly true. Here's basically what happens along the way: every time you process a roll of film, the film, wet with developer, slightly dilutes the bleach. Consequently the chemical components of bleach gradually become less and less concentrated, although they will continue to work adequately for a long times.

The bigger problem is that the bleach will eventually run out of a key component - bromide ion. What happens is that all of the developed silver IS converted back to silver bromide which can be dissolved by the fixer. But... that bromide is lost from the bleach. If your film is heavily exposed, the loss happens faster. Eventually you will "hit a wall," and lose your ability to bleach.

In a normal replenished process adding a small amount of replenisher essentially cancels out the losses, keeping your process tank in the spec condition. But, since you are always increasing the volume slightly, you end up with too much bleach, and have to throw some of it away. Which you hate to do since it is so expensive. What EdSawyer is doing is to save that "waste" material, then "regenerate" it back to the same chemical specs as a fresh replenisher, and reusing it as same.

 

[NortheastPhotographic]

So strange, Kodak doesn't even seem to sell the regenerator. Where can I get some?

 

[Mr Bill]

I don't know any good sources, but B&H does seem to carry a listing - https://www.bhphotovideo.com/c/product/926453-REG/kodak_3626850_flexicolor_c_41_bleach_iii.html

Probably larger than you want, though.

Ps, you should probably check the Z manuals to see if this is advisable or not, even the replenishment with your machine. Sometimes Kodak's recs in these areas confuse me - not the specifics of WHAT they say, but WHY they say certain things. In my experience Kodak has tended to be conservative in protection of the customer, perhaps against dumb mistakes one might make, so I suspect this might have something to do with recs that don't seem to have a good basis. Anyway, go counter to these at your own risk.