Freezing C-41 developer components?

Christophoto · Jan 25, 2017

Sorry if this has been beat to death, I searched and saw a few references but didn't come away convinced of anything. I have a fresh Fuji x-press 5L C-41 kit and only need 1L at a time. I've read that at least one of the developer components goes bad quickly once opened and thought maybe I could purge enough air out, but now I read about freezing instead. First recommendation was to mix all 5L into 1L batches and freeze the extra 4 batches, and the second recommendation was to just mix 1L and freeze the rest of the concentrates. Good idea or not?

Also, the instructions for mixing the developer cracked me up, photo attached. Better not forget that last 3mL of water if you're mixing 1L.

RPC · Jan 25, 2017

Do not freeze or refrigerate anything. Mix all of the developer and put it in 1 liter glass jars filled to the top and tightly sealed and it will last many months at room temperature. High quality plastic such as PET also works well from what I have heard, but I use glass.

Christophoto · Jan 25, 2017

Many months? The directions say that mixed developer in full glass bottles is only good for 6 weeks, are they just being highly conservative? I'm hoping to get it to last lot longer than that.

Sirius Glass · Jan 25, 2017

This is not a good idea. Freezing film is good. Freezing chemistry, not so good.

Christophoto · Jan 25, 2017

Understood. Think I'd have better luck mixing it all and bottling into 1L bottles, or mixing 1L and purging the remaining concentrates with gas? Never tried purging the air out, not sure if the damage is done and it gets oxidized when you open it for the first batch or not.

amateur_trombonist · Jan 25, 2017

Try the Swissmar Epivac system. Get some glass bottles with the standard soft drink soda pop neck - one-liter medicine bottles from a pharmacy also work. I've been using this system for 2 or 3 years now. Just keep pumping until there is no air left in the bottle. Recheck the vacuum in each bottle daily until you're sure there is no air leakage, then occasionally thereafter.

Christophoto · Jan 25, 2017

Hmm, that system does look pretty easy. The real question now is how long will it prolong the life of mixed developer for. Thanks for the tip.

RPC · Jan 25, 2017

Christophoto said:
Many months? The directions say that mixed developer in full glass bottles is only good for 6 weeks, are they just being highly conservative? I'm hoping to get it to last lot longer than that.

Yes, many months. Success with this method has been reported by many on this site. I use Kodak chemistry, but they too, say only a few weeks.

Do not freeze, do not use partial concentrates. The key is to prevent oxidation, and filled and sealed tightly in oxygen-impermeable containers does this.

Christophoto · Jan 26, 2017

Couldn't find 1L glass bottles I liked anywhere online, so I gave up and bought two cases of brown glass swing top 1L bottles from my local home brew supplier. Still need to see if I can find some glass marbles in town so I can mix tonight. If the bottles don't work for some reason I can always use them for my next batch of beer. Can't imagine them not being airtight if they're good enough to carbonate beer in.

alanrockwood · Jan 27, 2017

Freezing solutions is a chemists standard way of preserving them. It does not always work. It depends on what is being frozen, but in most cases a frozen solution degrades slower than one held at higher temperature.

However, one danger in freezing of solutions comes from what comes later. In general, freezing of solutions tends to drive solutes out of solution. At the very least the frozen material is not spatially uniform in composition. (There's some pretty fundamental chemical thermodynamics behind the cause of this effect, but I won't go into detail right now.)

What often happens when the material is subsequently thawed is that there are concentration gradients in the thawed solution. In other words the concentration is not the same at every point in the solution. In the worst cases there may also be undissolved crystals of the solute(s).

The standard way of dealing with this is to mix the solutions after the thaw but before removing any of the solution for use. This may be tricky if there are undissolved crystals, because some crystals are hard to re-dissolve.

In a few rare cases freezing a solution may actually de-stabilize the solution. I am not talking about solutes crystalizing out, but rather about chemical reactions that may occur, but this sort of thing is very unusual. The most common problem is the one about non-uniformity in the thawed solutions, including the possibility of components of the solution becoming undissolved during the freezing process.

I am a professional chemist with a pretty good knowledge about chemical thermodynamics and how thermodynamics relates to solutions, so if you would like to know more about the general principles involved please do not hesitate to ask.

Martin Rickards · Jan 27, 2017

Don't forget that any water left open to the air, including tap water, will have about 9mg/litre of dissolved oxygen at 20ºC. It would be better to boil before making up the solutions.

RPC · Jan 27, 2017

Ideally, yes. But there seems to be enough preservative in the developer to consume most or all of the oxygen in the air dissolved in the mixing water, which then will inhibit oxidation of the developer over time, if stored properly.

kmphoto · Jan 28, 2017

I keep it pretty simple.
Nearly 50 years ago, a old photographer told me…..
"To top your bottles off completely to the top using clean, dry glass marbles".
You just keep adding them as you use the solution.

It’s always worked for me. They displace the air and keep the bottle topped off until you get down to the bottom.

I buy mine from Amazon by the bag or box.

https://www.amazon.com/s/ref=nb_sb_...s&sprefix=marbles,aps,1007&crid=2BKY8206G8565

(You can always teach your kid how to shoot marbles in the backyard).

Sirius Glass · Jan 28, 2017

I also use marbles when I cannot squeeze out all the air.

Christophoto · Jan 28, 2017

I already ordered a big sack of glass marbles last night. My plan now is to mix my 5L batch, fill 4 of my 1L glass swing top bottles to the brim and the 5th one top off with marbles. I want at least 1L of working solution so I can process 2 120 rolls in a Paterson tank at a time, and filling a bottle to the brim I'd imagine will give me more than 1L, hopefully enough to make up for losses as I go and top off with marbles as I go. The 5th bottle I'll just use for single roll development when I run out of the first 4. Now I'm just wondering if I'll have to top the first bottles off with fluid also as I go. I also bought some 1L clear beverage jars, basically jars with handles, that I'll transfer chems from the bottles to when I'm preparing to develop so I can pour in and out of them quickly without messing around with funnels. I'll measure and mark 1L on the jars so I'll know if my marble topped bottles are getting low. Did I miss anything?

kmphoto · Jan 29, 2017

> Did I miss anything?
No, you've got the concept down.
It's called the K.I.S.S. method.
(keep it simple stupid)........

Photo Engineer · Jan 29, 2017

I'm going to put it more simply than Alan did. There is a mix order of the chemicals; A, B, C! If you do it out of order, some chemicals may not dissolve correctly in the water you are using to dilute it. Also, some chemicals have to be added first so as to remove excess oxygen and metal salts in case you are not using distilled water.

If you chill or freeze the mixed developer, it can cause crystallization of the contents and they may not re-dissolve properly thereby causing problems.

You can safely chill or freeze the concentrates in unopened bottles though. Just warm to room temperature and let stand for a few hours before diluting as per the instructions.

PE

TattyJJ · Feb 2, 2017

Photo Engineer said:
I'm going to put it more simply than Alan did. There is a mix order of the chemicals; A, B, C! If you do it out of order, some chemicals may not dissolve correctly in the water you are using to dilute it. Also, some chemicals have to be added first so as to remove excess oxygen and metal salts in case you are not using distilled water.

If you chill or freeze the mixed developer, it can cause crystallization of the contents and they may not re-dissolve properly thereby causing problems.

You can safely chill or freeze the concentrates in unopened bottles though. Just warm to room temperature and let stand for a few hours before diluting as per the instructions.

PE

Out of curiosity, if i was to say buy a kit but only wanted to mix half of it. Could i then top up the unmixed remainder with marbles and freeze to preserve it?

Photo Engineer · Feb 2, 2017

Yes, I do just that Tatty. But, I use Nitrogen.

Christophoto · Feb 2, 2017

Dang, maybe I should have done that instead of mixing it all. Oh well, it'll be a good test to see how long they last in completely full swing top bottles. I made a goal to seriously ramp up my C-41 use this year so I might use it all before it has a chance to expire anyway.

Freezing C-41 developer components?

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