repeating the C-41 blix step

[h._shafi]

Hi,

 

I think that I pushed my luck with the Tetenal C-41 blix the other

day. The unexposed part of the color negatives has a purplish tint

and is darker than the usual orange. I was experimenting with

reusing the chemistry for two runs, which is possible according to

Tetenal, but I forgot to extend the blix step from 4 to 6 minutes.

The negatives are now dry and cut, but can I still put them through

a prewash, blix, and wash cycle to see if I can recover from the

mistake? Of course, this could also be a developer problem but I

don't have enough experience to tell the difference.

 

Thanks in advance.

 

-Haz

[rowland_mowrey]

Haz;

 

Rebleach, rinse, Fix, wash, and stabilze at the normal temperature for the normal times will work with EK or Fuji Hunt chemistry. This should work if it was the bleach.

 

IDK if it was the blix. They are hard to design and are sometimes not very stable. IDK what they might do to the film. There was one report here that overbleaching caused problems in a C41 'compatible' blix. I have no idea if it was correct.

 

Ron Mowrey

[h._shafi]

Thanks Ron. I was hoping that you'd read this :-) I'll try and report back if successful.

 

-Haz

[stephen_allan]

Hi Haz

 

I use the Tetenal C-41 chemistry a lot, and as long as you increase the times as specified for the developer and blix, you can get 12 films per litre over four runs. It is rare that I actually do the full 12 films, but I routinely do three runs with 8-9 films, and have experienced no problems.

 

Tetenal state that the blix step can be extended by up to 50%.

 

<p>The JOBO Fototechnic site has some useful info on this <a href="http://www.jobo-usa.com/instructions/instructions_tetenal_mono_c-41.htm">C41 1 litre Instructions</a>

 

<p>Steve

[h._shafi]

Steve,

 

Are you using the 1 liter or 5 liter kit? I've been using the 5 liter kit and running 4 films at a time (mix of 24 exposure 35mm and 120) using 500ml of chemistry at a time using a Jobo 1540. I usually get 8 films per liter without any problems, but this time, I was trying to squeeze 6 films out of 500ml when the problem above arised. I went ahead and put the negatives through another blix cycle tonight. The negatives are drying as I'm typing.... We'll see. BTW, why do you only run 3 films? Are you using a Jobo 1530?

 

Thanks!

 

-Haz

[stephen_allan]

Hi Haz,

 

I use the 5 litre kit, and usually mix up a litre of chem at a time. Generally I use the Jobo 1540 tanks, using the full litre in the tank for each processing run. Though I have had success processing 6 films (3 runs of two) using 500 ml of the chem in both 1520, and 1540 tanks. I run three films at a time as it fits nicely with the capacity of 12 films over four separate runs.

 

On thing I do with the blix, is to give it a good shake to aerate it. I do this after first mixing the blix, and between each processing run. Tetenal state that this aids the action of the bleach.

 

I often only do three runs as I use a fair amount of 400 ASA film for 35mm, and Tetenal suggest that the chemicals have a lower capacity when processing faster films (400ASA and greater). Though this probably only affects the developer. If I am using slower films, and I have enough to process, I will go to the full capacity of 12 films in a litre.

 

Steve

[rowland_mowrey]

Gentlemen;

 

Please read the MSDS information on the bottle of any C41 bleach fix (blix). If you see the words "Ferric and Hypo or thiosulfate" on the label in the listing, you must know that these two chemicals react with each other as soon as mixed together. That is why they are shipped in an A and B part.

 

Take it from a guy who tried to develop (and did) a C41 blix, that particular mixture is NOT stable and loses activity rapidly once mixed. That is why both EK and Fuji-Hunt supply a bleach then fix process. It is to insure that you, the customer, does not get pictures with retained silver in them.

 

So, when you use a C41 or E6 process with a blix, if it uses iron salts (ferric) mixed with hypo (thiosulfate) you are skirting disaster.

 

The lower dilution of the RA paper blix makes this combination successful. That was the only blix I designed at EK that was marketable. Just FYI, it was internally marked as Blix 1066 at one time, as that was the date it was first formulated for the then-new EP2 Ektacolor paper process. I do wish I got just a penny for every gallon sold. ~sigh.... But, as you will find out, film blixes are a different matter.

 

Good luck to you.

 

Ron Mowrey

[h._shafi]

Steve/Ron,

 

Thanks again for your great input/advice. BTW, the blix cycle didn't fix the problem, so I assume that it was underdevelopment.

 

Steve, I think that I'm going to stick with 8 rolls (mix of 35mm 24/36 & 120) per liter of Tetenal since I've had good success with that. Maybe I should follow your practice of running the full liter of chemistry for each run though. Right now, I use 500ml/4 rolls (usually 100/200 ASA) as one shot for 3:15 minutes. I don't understand the pros/cons of using more chemistry as far as developer effectiveness/depletion are concerned. BTW, where do you get your Tetenal chemistry from? I've been getting it from Adorama, but their freight charges are very high for that stuff (compared to what I pay Calumet for shipping the heavier 10L RA chemistry for example).

 

Ron, I want to make sure that I understand your input above. I think that your warning about the C-41 blix applies to the Tetenal kit. I usually mix and do all the runs within a day so the reaction issue is probably insignificant. However, I've been looking into Flexicolor chemistry lately. Unfortunately, it seems that they don't market a 5 or 10 liter C-41 kit for rotary processing and their 1 Gallon kit has considerably lower capacity compared to Tetenal (about 4 rolls per liter). If there's anything better than the 1G kit that I've missed, please let me know. The unmixed kit needs to last for a max. of x months, where x is the number of liters since I typically go through a min. of 8 rolls a month. So far, the tetenal kit seems to survive that duration.

 

Thank you both again!

 

-Haz

[stephen_allan]

Hi Guys

 

<p>Ron, thanks for the extra info on the blixes. I have generally used a batch of solutions on the day I have mixed them. As you say, the fact they are shipped as separate parts gives the game away :^) (for my E6 processing I do use the Tetenal 6 bath which has the separate bleach and fix baths).

 

<p>Haz, I get my Tetanal chemistries direct from <a href="http://www.tetenal.co.uk/acatalog/Tetenal_Online_Classics_6.html">Tetanal</a> in the UK. If you are in Europe, it may be cheaper to contact Tetenal in <a href="http://www.tetenal.com">Germany</a>, as they may have cheaper delivery on the continent.

 

<p>As for the use/effectiveness/depletion issue, all I can do is outline what I actually do, which has always given me good results. In my case I am using the chemicals over several runs, and not as a one-shot as you are.

 

<p>If I am using a litre of chemistry at a time (i.e. to do 8 - 12 films) I always use the full litre of mixed chemicals for each run, and extend the development/blix times as recommended for each run. <p>I only load a maximum of three films in the tank, even if it will take four, this seems to fit well with Tetenal's statement that the chemistry can be used for a maximum of four separate runs to process 12 films. If I was processing 8 films, I would do two runs of three, and one run with two films.

<p>If I am using 500ml of chemistry I will process a maximum of six films. I use the full 500ml for each processing run. But will only load two films in a tank for any one run for a maximum of three runs.

 

<p>So I think you are fine on the capacity side, doing four films one-shot in 500ml, though I would be tempted to try extending the processing times to allow for the loading on the processing solutions.

 

<p>Steve