what does c 41 Bleach starter do
I need some help clarifying an issue I have.
I know some C41 bleach products are available pre mixed and ready to use (kodak Bleach NR) and some (Kodak Bleach III) require a starter added to a replenisher to make a tank solution.
I acquired some bleach that is similar to the latter Bleach III that requires starter) that is made by Silver Pixel and the limited info I can find says a starter is required.
What is in the starter and is it necessary? Even the Kodak bleach starter is hard to source and I'm hoping I can get by with just a replenisher solution.
What does the starter add/do that facilitates correct bleaching in C41 process that would be absent in just the replenisher?
As always, thank you in advance for any help you may be able to supply.
Bleach takes elemental silver and moves it to ionic silver. The fixer then removes the ionic silver. It gets the ion from the Ferric Ammonium EDTA in the bleach ferric ion becoming ferrous (I might have the electron thing backwards). It also removes the dye formers that have not formed a dye in the colur developer, but I am not sure what the mechanism that does this is.
So I would guess that starter gets the bleach acting as though it has had a few rolls of film though it. It also usually is added to the replenisher along with water to make up the final volume of working solution. Replenshers are usually more concentrated than working solutions and replace the 'active ingredients' as they are incrementally added.
One way to 'fake' the starter action might be to fog some c-41 films and then develop in a b&w film developer to get lots of elemental silver, and then let them soak in the blaech. There should be lots of elemental silver to cut back to it ionic form , and oodles of uncoupled colour formers to digest. I don't quite now what the dilution amount of water should be used to take your replenisher and make a working solution. There are instructions for big photo labs to check thier solutions with hygrometers, but that is beyond the realm of most of us here.
Sorry, but I don't know how many exactly would be required. This thought comes to me from using Harveys 777 b&w developer, which has to be 'saesoned' with a couple of wasted films if you are mmixing it from a fresh bath. With 777 you keep the overflow from after the replenishment is made, and use the 'old gunk' to start the next batch after the first batch with film seasoning is done.
A wierd alternative that the Harveys route suggests is to beg some bleach overflow from a friendly minilab operator to act as your starterless working solution blaech. Start bleaching with this route with perhaps 1/2 to 3/4 of the tank made up of used 'munge', and then replenish from there.
C-41 bleaching can be visually inspected under tungsten everyday indoor lighting, after the film has been in the bleach for a minute of so. You can see whenthe film has bleached. If it has not bleached in the specified time, bleach longer, and next time add more replenisher.
I do/have done home brewed c-41. Presently my bleach is e-6 bleach, of which I I found three jugs to make 5l each at the HHW depot re-use shelf when I was dropping off used fixer one day. Once that is gone I will be back to my old bleach method with uses 80g of K ferricyanide and 20g of K Bromide per liter of bleach. I woul mix 2L at a time, and make 1L the working solution, and the second L the replenisher, adding 45mL per 80 square inches of film processed. I would harvest the overflow and when the 1L of replensiher was gone, turn the working and overflow into the HHW depot. This is C-22 belach, the precursor to C-41, and it works faster; 2.5 mnutes to the e-6 recommended 6 minutes as I recall.
I believe E-6 bleach is rated to 30 rolls of 80 sq in before it exhausts without replenishment, but I play it safe, and turn it in to the HHW after I have done 25 rolls.
my real name, imagine that.
Once again Mike,
Thanks for your experiences.
I do have plenty of c 41 films that are rather cheap (1usd a roll or less) if you get them outdated.
perhaps I should just run some film to season the bleach and see what happens.
I was taught b&w and some rudimentary color at an excellent local community college and my mentor up there drilled in process control so I'm always paranoid with not going by the book. I specifically departed from kits with blix due to the excellent advice I've gained here.
I'd love to hear any other thoughts on how I should proceed from some of you with experience.
I should mention that I'm running ss tanks and reels in a hand inversion setup.
Well I would consider just trying to buy the colour developer; I am not sure all of my colurs are bang on with the home brew mix I use. I have heard of people buying the 5L kit,and decant it off to samll sealed bottlles that are openned one at a time as needed, and otheriwse kept in the fridge.
the stop is dilute acetic acid, glacial 10mL per L.
I wash 1 min after stop to keep the bleach pH consitent.
I wash 2x 30s after bleach to prevent carry over into the fix for the same reason.
Fix is a basic rapid fixer I scartch mix.
I learned a lot by harvesting from rec.photo.darkroom archives about 5 or more years ago. Now it is just almost all spam. Then I discovered this place - kind of like an oasis after a desert.
I have files from Maxwell Sandford, who also home brews; he hangs out here as MTS, and has fed lots into newsgroups in the past as well. I cannot locate the file he sent me with his notes at the moment, but have the hard ciopy at home; he may be able to send you the same if you ask.
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Basically, bleach starter for a color process is nearly an oxymoron. You do not need a bleach starter, a fix starter or a final rinse starter.
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I had the attachment as a rtf, which this site does not support. Hope this .doc upload helps.
my real name, imagine that.
So, I guess I can stop obsessing over the lack of starter. Thanks PE.
Mike, thanks for that .doc , I'm still perusing it. Good info.
Last edited by brucemuir; 11-10-2009 at 02:42 PM. Click to view previous post history.
Hm, how would I use this solution as bleach then?
Originally Posted by Photo Engineer
I think that the instructions are clear. But, as I said, the starter is not needed.
Just adding 300ml water to 700ml replenisher will make perfectly OK bleach?