Digibase C41 mixed life span

[luke778899]

Hi,

I mixed 500ml of stabilizer, developer, bleach and fix from the digibase C41 kit about 3 months ago. I only developed 4 rolls and then they have been untouched and well stored in air tight containers in a cool, dark environment. Now, I'd like to develop another batch of film and I'll probably mix up some more developer to be on the safe side but how can you tell whether the other chemicals are still workable. I know how to 'clear' test the fix, but is it possible to test the stabilizer and bleach?

Thanks for the help.
Luke

 

[Lamar]

I'm pretty sure the stabilizer would be fine but the developer would definitely be in question. 3 months is pretty old for C-41 developer and even more concerning would be it's a small 0.5L batch that has had 4 rolls run through it already. I would just mix more. I think I used to see a real drop off at about 2 months and around 8 to 10 rolls in a 1 Liter batch.

 

[Simonh82]

I've used digibase c41 chemicals that are over a year old with no noticeable detection. I've still got the same partially regenerated bottle in my fridge which is now approaching 2 years. I might finally get a chance to use it tonight, after about 6 months of neglect. It has been fridge stored throughout and has always performed well. I scan my colour film so don't know how it would print in the darkroom.

C41 is much more robust than many people think.

 

[kb3lms]

Pour a bit of your developer into a small glass or dish at room temperature. Drop in a small piece of exposed film (should be color but b/w will do in a pinch) cut from a leader or such and see if it develops to a good density in 3 to 4 minutes. If it does it is probably OK. If it's dead, nothing (or not much anyway) will happen.

I, too, store my C-41 developer in the garage refrigerator in a tightly capped heavy PET bottle, which extends life by quite a bit. Glass would be even better if you have it. I've found that "Power-Ade" bottles work well. Also, I keep the bottle stored sealed in a good ziplock bag.

Freezing does not work, contrary to my once proclaimed success.

 

[Gerald C Koch]

Partially used chemicals are going to have a shorter life than unused ones. What many people do is to save up their rolls and then develop them all within a few days. This is the most economic way of doing things.

 

[bvy]

If stored properly, the developer should be fine. To add to the good advice of kb3lms, I usually put a piece of clear tape over part of the emulsion and then proof it as he describes. The emulsion under the tape shouldn't change color; the surrounding area should turn quite black. In other words, look for strong contrast between the taped and untaped areas.

The other chemicals degrade more with use than time.

 

[Simonh82]

I finally got around to developing some colour film with my two year old Rollei chemistry and it worked perfectly. The scanned results are here http://www.flickr.com/photos/28305528@N02/sets/72157641582684004/. This is Ektar 100 developed for 4 minutes to compensate for the age and use of the chemistry. The film was scanned on an Epson V500 and some basic post-processing was done in photoshop. I know that the digital route offers more flexibility for colour correction so these may not wet print so well if there are colour cross-overs but there is plenty of life left in the developer and the colours were not difficult to correct with my very basic photoshop skills.