C-41 developing options with focus on shelf life of chemicals

When I do C-41 processing I collect the equivalent of 16 rolls of film and get all my processing done in two to three days. Then I dump the chemicals. Other people have been successful spreading it out more, I just have never done that.

 

One suggestion is to read the entire forum from the beginning (yes, all posts) related to C-41 processing. I did this as a sort of seminar/training course, and it helped immensely. Plus it was enjoyable.

Developer is the only solution that is sensitive to oxidation. The best practice on this site is to store in 100% full containers, tightly stoppered. I use 1 liter, 0.5 liter and 0.25 liter PET plastic beverage bottles, with the label removed and re-labeled with the appropriate information. Another good storage material is bag-in-box systems, such as for storing wine. Be sure to check that the bag includes an EVOH plastic layer, this is the oxygen barrier.

You can process film in batches as SG suggested, or you can utilize a replenishment system. A replenishment system relies on a certain amount of throughput, which from the sounds of your post, you may not be interested in.

Bleach doesn't necessarily have a shelf life in terms of losing strength because of oxidation. It is depleted through use (processing film). Same with fixer. Rinse isn't depleted by processing, but it gets diluted from previous baths, whether they be plain water or fixer.

The Kodak CAT numbers below are from my most recent receipts from Unique Photo in New Jersey.

1. 8231672 Developer / replenisher, to make 5L
2. 6601074 Developer / starter 1.2L

Mix 1 and 2 with water according to the instructions to make 7.5 liters of working strength developer.

3. 8255549 Bleach/replenisher: product includes 5 liters of chemical, use undiluted as a working solution
4. 1077577 Fixer/replenisher, to make 5L: dilute 1:1 with water to use as a working solution
5. 8673170 Rinse: mix with water according to the instructions to make 5 liters of working solution.

 

I have no problem with preferring to limit waste and expense.
However, don't be afraid to make a choice that involves a small amount of waste, and a little extra expense, in exchange for ease of use and quality of result.

 

Regarding LORR, etc., I went with bvy’s list for my first batch. So I did not choose or discriminate between the options. The only thing I changed is bleach and fix, choosing to purchase single chemical, larger containers. For me working out of larger containers and avoiding the fussy minilab fitments of the processing unit were factors.

I replenish bleach and fixer; you can look at this as a quasi mix on demand method. But the initial 1 liter working bottle needs to be established.

For developer I mix the entire quantity. One of the developer components is highly active and is used in very small volumes. To mix on demand does not make sense to me because of oxidation with each opening and decanting occurrence, plus partially full storage of an active substance which is to be avoided. Don’t do this. The other scenario you mentioned above seems like a version of on demand mixing. For bleach and fixer this makes sense to me. For developer it does not for the reasons given above.

For tank rinse, the concentrate is used in such small amounts it would be a pain for me to mix on demand. It doesn’t have the same oxidation risk that developer does, so in principle you could mix on demand if that’s what suits you.

 

The LU/LORR/SM stuff will confuse you to tears. Here's everything you need chemical-wise to get started (not including water). Unique Photo in New Jersey stocks and ships everything (to the US), so I refer people there. But you can get the part numbers from the links shown.

#1 - C-41 Developer Replenisher ($13.95)
http://www.uniquephoto.com/product/c-41-dev-repl-lorr-tm-5l-ek-kodak-xhaz-hazsp1-832-0608-8231672/

#2 - C-41 Developer Starter ($14.00)
http://www.uniquephoto.com/product/kodak-c-41-dev-starter-lorr-1-2l-6601074/

#3 - Separate Bleach and Fix ($38.00)
http://www.uniquephoto.com/product/...sing-unit-f2-for-color-negative-film-1173319/

#4 - Final Rinse ($4.98)
http://www.uniquephoto.com/product/kodak-c-41-rinse-replenisher-tm-5-liters-8673170

#1 will make 5 liters of developer. I would mix it all at once, not on demand (see Wilmarco's post). It's a box containing three small bottles (A, B and C) with clear instructions.

#2 is developer starter. You'll dilute some quantity of it with water and add it to the 5 liters of developer. You'll get about 6.5 liters of working solution developer. You'll have starter solution left over to use with your next purchase of #1. Again, there are clear instructions on the packaging.

#3 is a box containing two bladder bags. One is bleach (greenish black, 1 liter) which you'll use straight. The other is fixer (clear, 2 liters) which you'll mix 1+1 with water -- all at once or as needed. No starters are needed for either of these. Plan to reuse these solutions; one purchase should last a long time.

#4 is a final rinse, the last bath before hanging the film to dry. Dilute according to the instructions (~1+100). Use one shot or reuse sparingly.

If you want to add a stop bath between developer and bleach steps, I use 5% distilled white table vinegar, mixed 1+4 with water.

 

I didn't have any problems with C-41 press kit sold by BH for more than one year. Bottles with squeezed air and stored in the refrigerator.

 

Others participating in this thread are much better sources for that info, because for C41 I'm not currently developing my own.
My comment was more general - essentially a recommendation to step back a bit and look at the various factors in context. I see a lot of posts where people seem to be complicating their choices tremendously because they don't want to waste about $4.00 worth of chemicals, due to the fact that they didn't use it up within six months (XTol being the perfect example).
What I do recommend, whenever possible, is to have unopened chemicals in reserve before you are likely to need them.

 

If you are interesting in shelf life, concentrates have a much longer stability than working solutions. I have used a Tetenal Colortec kit for over nine months doing partial mixes without major problems. There were some minor color shifts with different working solutions but nothing really important and easily corrected with the digital edition or enlarger.

 

The F2 boxes are seriously overpriced for what they are. They are also discontinued, so best to not get used to using or relying on those. Getting separate bleach III and C41 fix is a more economical solution anyway.

 

I've used working solution developer a year after mixing it with no signs of degradation. Others have reported longer. I store it in a cabinet at room temperature in my basement. Refrigeration really isn't necessary. I absolutely would NOT mix it as needed from concentrate. Two reasons: The concentrates don't keep well at all, but the working solution stored in good volume in bottles filled to capacity (glass or thick plastic) are quite stable. Also, you're unlikely to mix with the same accuracy every time. Part C is the critical component and a very small bottle. So if consistency is important, prepare it all at once.

 

That is a shocking affirmation for me. Why color developer is packaged in three different concentrates form? PE made a recent statement regarding presentations as a single component...

"a color developing agent keeps best in solution when it is acidic. It also keeps best when in the presence of sulfur dioxide or sulfite ion. Therefore, color developer in a liquid kit keeps best in a solution of acid (sulfuric or hydrochloric) and sulfur dioxide or sodium sulfite. A single part kit is alkaline, and therefore keeping is pretty poor."

https://www.photrio.com/forum/threa...o-monopart-c41-kit.148544/page-6#post-2026885

Two of the three concentrates (parts 1 and 2 of Tetenal Colortec, parts B and C of Kodak Fleixcolor LORR) are packaged excactly like that, acidic pH and in some presence of sulfite ions. There is only one part alkaline (Part 3 of Tetenal Colortec, Part A of Kodak Flexicolor) but it does not include any developing agent, just acelerators and preservants for the working solution. My experience supports this, I have used Tetenal kits along nine months doing partial dilutions without any care about the keeping conditions of the concentrates with any complaint from my side.

I think bleach and fixer doesn't matter so much how you keep it, but if you use a Blix is definetevely better to keep it as separate concentrates. Also I would take care with part 2 of the blix with Tetenal kits (the "fixer" part). Like other fixers from Tetenal for B&W, they have a pretty poor shelf life compared to products from Ilford or Kodak and I would suggest to keep it in a fridge or in close airless bottles to be in the safe side.

C-41 is a quite flexible color process and film tolerates some rudeness/errors in the development without much complaint. If someone seeks precision and reliability...go to a professional lab.

 

The chemistry lasts much longer if you mix it, and store it properly. I have had mixed C-41 and RA-4 last years when stored in glass bottles filled, and sealed tightly. The solutions hardly even change color. I use canning jars which have a good seal.

Mixed, the preservative is combined with the developing agent which protects it from air dissolved in the solution. But storing it properly is important to exclude oxidation from air outside the solution.

 

I'd like to see a source that the F2 kit has been discontinued. The price has gone up, but someone processing C-41 casually can get a lot of mileage out of it. I put over a hundred rolls through the last kit bleach that I got, and had fixer leftover. Anything film related can be discontinued by the time we get around to reordering it.

 

Tedwar, the stored C-41 (Kodak) developer has the starter added to the replenisher, making it ready to use. The RA-4 developer is Kodak RA-RT replenisher used without starter.

I had some C-41 developer mixed in 2011 and used it up in 2015. It worked well, showing no sign of any problems, and I believe it could have gone longer. I have gone about three years with RA-4, with prints showing no sign of degradation.

 

Tedwar - yes, those are the right parts you listed. Get some bleach regenerator too if you can, that will allow recycling the bleach nearly indefinitely.

You can probably skip bleach starter if you want - I've never bothered with it, but it wouldn't hurt to use it either. It basically pre-seasons the bleach, mostly used if you are running replenishement line, generally.

 

I concur with all of this. A year with C-41 and probably more than a year with RA-4. I use thick plastic 600ml drink bottles with good caps, clearly marked, and filled to capacity. For C-41 I recently switched to one liter glass bottles with polyseal caps, but not because I was having issues. I like the larger size and that it's glass.

 

It is pretty straightforward for me, I just follow mixing directions and have mixed up to two gallons at a time in a plastic bucket, but I mix it all. Then I pour it (slowly to minimize aeration) usually into half-gallon canning jars. I write the date on the jars with a sharpie. As I use it I dump it onto smaller jars--I have half-pint, pint and quart to keep them full.

 

I mix it in a steel pot, used only for this purpose. As I recall the batch produces 7.5 liters of working strength developer. I decant this from the pot into 7x1 liter bottles and 1x0.5 liter bottle, using a plastic funnel that is used only for this purpose.