How long does E-6 chemistry last?

[Ariston]

I bought some E-6 chemistry, intending to shoot enough rolls to make use of it. But after several months I have still only shot three rolls. I don't want to combine the parts and waste it on just three rolls, but I also don't want it to expire.

Does anyone know - how long does it last in its un-mixed form?

 

[Donald Qualls]

In concentrate form, it should be good for at least two years from date of manufacture -- and with good storage conditions (room temp, reasonably constant) might well last two or three times that. Once mixed, it should be good for at least two months -- if bleach and fixer are separate, they'll likely last much longer than that. Color developer is the limiter. BTW, remember that the first developer is a one-shot, mix from concentrate just before use (at least in most E-6 kits). Still ought to last longer after opening than the color developer will last after mixing.

 

[Rudeofus]

There are a few things which determine how long your chemistry will last:

1. have the concentrate bottles been opened?
2. which e6 kit do you use? is it a BLIX kit or one with separate bleach&fixer?
3. have you mixed the whole kit to make working solutions, or did you mix only parts and kept the concentrate bottles with the rest?
4. do you have inert gas to protect concentrates and working solutions?

Here is my personal experience with Tetenal's E6 kit. I mixed only small volumes of working solution as needed, and kept the rest of the concentrates in their bottles and sealed them off with inert gas:

• First developer starts turning dark after 9-12 months. You have to extend FD time at this point to get normal looking slides
• Color developer also turns dark in this time frame, but this is less critical, since color development runs to completion.
• It is very important to protect the BLIX part containing the thiosulfate (that's the bottle with the light yellowish liquid, not the deep red one) with inert gas, or it will sulfur out within 6-9 months.

If you use a kit with separate bleach&fixer, or a BLIX kit with three BLIX concentrate bottles, you should not have the sulfuring out issues, but FD and CD concentrates still face the same problems. Working solutions should be used within 2-3 weeks IMHO.

 

[Nodda Duma]

I’ve found after developing E-6 over the past several several years (Arista Rapid Kit) that I start getting paranoid and dump the working solutions after about 6 months. It lasts that long as long as you compensate per instructions. If I develop a lot from a batch — to the point that compensating development time is like 9 minutes — then I dump it then, too. Figure at that point I’ve gotten my money’s worth out of it. Color shifts are non-existent for E100 (new and old), Velvia, Provia, Aerochrome, Sensia

 

[Ariston]

Thanks guys. It is a sealed kit with blix, so hopefully it will be okay. I need to shoot more E-6.

 

[peter k.]

Maybe a little off topic:
Just about completed with my first Tetenal E-6 kit, have one more batch we can mix, but curious about your mixing of small volumes, can you give more detail. Also from who do you order your inert gas from. Thanks p.

Here is my personal experience with Tetenal's E6 kit. I mixed only small volumes of working solution as needed,

 

[Donald Qualls]

I've used butane lighter fuel (available most places that sell cigarettes) for gas blanketing with very good results in the past. Not recommended if you smoke in your darkroom, though...