Ektacolor RA blix concentrate shelf life (opened)

[Wayne]

I've got some open concentrate in original bottle about 2/3 full but it was opened 2 years ago. I presume its toast but without any developer at the moment can I be sure?

 

[koraks]

What does it look like? My Fuji blix concentrate had visibly gone very bad (sulfured out) after about a year after opening the bottle.

 

[Photo Engineer]

The red part will last a long time. The "clear" part is bad when the concentrate goes cloudy or otherwise looks bad. You can use the C41 fix as an emergency replacement, but you have to double or triple the wash.

PE

 

[Wayne]

The red part will last a long time. The "clear" part is bad when the concentrate goes cloudy or otherwise looks bad. You can use the C41 fix as an emergency replacement, but you have to double or triple the wash.

PE

It appears that I only have the red part anyway. I think the clear part "A" went bad very soon after I bought it several years ago and I just hung onto the B part. But (all sorts of surprises around here!) I found a full gallon of mixed, unused blix also 2 years old. But it looks perfectly good with no precipitate and smells normal and it turned an undeveloped scrap of RA-4 paper white in about 10 seconds. Think it is good?

I will only be able to print for about 6 weeks so I don't want to buy new developer AND blix if I only need the developer, especially since the blix is more expensive.

 

[koraks]

There's a chance the mixed stuff is still good, but I'd recommend dropping a b&w test strip into it instead of blank ra4 paper. The clearing you see with ra4 is just some dyes rinsing out, not necessarily the silver. Developed b&w paper should largely clear within a few minutes.

 

[dkonigs]

As I just opened a fresh package of this stuff, and only mixed 1L so far, I'm wondering what the expected shelf life actually is. More specifically, is it better to mix the concentrate in small batches as needed (e.g. 1L at a time) or to mix the whole thing all at once (into a collection of full bottles of stock solution that I gradually work my way through)?

 

[138S]

More specifically, is it better to mix the concentrate in small batches as needed (e.g. 1L at a time) or to mix the whole thing all at once (into a collection of full bottles of stock solution that I gradually work my way through)

It's always better to mix the amount you are to use, in special when something comes in two parts: it is made in two parts because when mixed a faster degradation starts.

What comes in one part usually is more stable (if mixed with distilled water) than the chem than comes in two parts. If water is not distilled then one never knows...

What I do with E-6 chem is mixing exactly what I'm to use in a short time, then I spray Tetenal Protectan inside the bottle to displace air and to make a protective "butane" layer on the liquid that displaces any oxygen up. You may also use bare butane or dust-off "canned gas".

To test, I sprayed Protectan in E-6 half emply concentrate bottles, after one year chem was OK, not noticing a change in the results, but anyway after a long storage always test with a single roll with not much important images, one never knows...

Also if you store concentrated bottles in a fridge probably you will extent its life and improve its preservation, using kitchen's fridge is not a good idea, but if having a dedicated and "controlled" fridge for photo then you may do it, some people think that all liquids inside a fridge are drinkable sure blix is tasty.

 

[dkonigs]

It's always better to mix the amount you are to use, in special when something comes in two parts: it is made in two parts because when mixed a faster degradation starts.

Except I've heard that with C-41 concentrate you need to mix it all once opened. That's because one of the parts apparently goes bad rather quickly once exposed to oxygen, but lasts longer once fully mixed into a working solution. (Photo Engineer gave a better explanation of this on another thread.)
Since RA-4 developer also comes in 3 parts, I decided to mix that whole batch up at once in the same way. However, just like my C-41 developer, I'm keeping it in a series of completely full and capped bottles. With any luck, that'll make it last a decently long time.

With blix, I'm not sure if the two parts actually react as part of the mixing process, as I'm assuming its just "a bottle of bleach" and "a bottle of fixer" that you pre-combine with water into a working solution. Of course I could be wrong here.

For preservation, Tetenal Protectan isn't something I can actually buy here in the US. However, I have started using "canned air" instead. With some chemicals, it seems like it gets "consumed" and causes the bottle to buckle inward significantly. Not sure if that's a good or bad thing.

 

[138S]

Except I've heard that with C-41 concentrate you need to mix it all once opened. That's because one of the parts apparently goes bad rather quickly once exposed to oxygen,

If you spray Protectan inside the concentrated bottle then oxygen is not a problem, you displace it and as butane is heavier than air any remaining oxygen is not in contact. When tetenal filled the bottle chem also was in contact with oxygen, no problem. The problem is having oxygen in contact with the liquid for a long time.

Test it on your own, split one bottle of C-41 color developer in three fractions:

> Store 1/3 with the mixed 3 parts in full bottles.

> Store 1/3 concentrates in a bottles with air.

> Store 1/3 concentrated in bottlea with Protectan or butane.

Wait six months andtest, you will find that bottle with preserving gas is perfectly ok and the other two are destroyed, specially the one that is mixed.

 

[dkonigs]

If you spray Protectan inside the concentrated bottle then oxygen is not a problem, you displace it and as butane is heavier than air any remaining oxygen is not in contact. When tetenal filled the bottle chem also was in contact with oxygen, no problem. The problem is having oxygen in contact with the liquid for a long time.

Test it on your own, split one bottle of C-41 color developer in three fractions:

> Store 1/3 with the mixed 3 parts in full bottles.

> Store 1/3 concentrates in a bottles with air.

> Store 1/3 concentrated in bottlea with Protectan or butane.

Wait six months andtest, you will find that bottle with preserving gas is perfectly ok and the other two are destroyed, specially the one that is mixed.

I don't want to go too far down this rabbit hole (and/or line of argument), as this thread is supposed to be about Ektacolor RA Blix.
However, I have actually tested one of these cases before. (And from what I've read, the concentrate bottles are actually sealed under inert gas, not air, which is why concentrates last longer when "still sealed from the factory" than they do when "opened and completely full.")

So during the summer, I bought a Fuji C-41 X-Press kit. This kit makes 5L of processing chemistry. I ended up mixing all 5L of the developer, and stored it in five completely-full 1L bottles. At right around the 6-month mark, I opened one of these bottles. I then used some of it to process a C-41 Process Control Strip. Once dry, I inspected this strip on my densitometer and compared its numbers to the reference. The results were pretty much perfect (within the margins of error of my instruments). They were actually better than the results from my previous processing runs, but I mostly credit that to improvements in my overall process (I switched from hand-inversion to a rotary processor). I then used more of that bottle to develop a few rolls of film, which also came out fine.

FWIW, I'm very glad that I actually decided to incorporate those test strips into my process. It gives me actual confidence in my processing chemistry and workflow, without having to rely on gut feelings based on aggregated hearsay. (Especially since official recommendations are extremely conservative and would lead to way too much expiration waste.)

 

[138S]

FWIW, I'm very glad that I actually decided to incorporate those test strips into my process.

I agree, this is the good way to do things.

(And from what I've read, the concentrate bottles are actually sealed under inert gas, not air, which is why concentrates last longer when "still sealed from the factory" than they do when "opened and completely full.")

For this reason if using Protectan (or butane) to displace air in an opened concetrated bottle you mostly restore the preservation conditions we had before unsealing.

Good if that chem is good after 6 months mixed and stored in full bottles, anyway IMO by using preserving gas in the opened concentrated bottles we have a better preservation, that would be as good as with sealed concentrate bottles.

My experience is mainly with Tetenal E-6 kit. Once mixed the color developer is what failed the first. By mixing only the amount I'm to use and spraying protective gas inside the original containers I get the same shelf life than with sealed containers, or very close to it.

Of course, allowing to enter air and shaking the concentrate bottle would not be smart.