Blix or bleach and fix for C41

chorleyjeff · Jan 30, 2007

I currently use Paterson C41 chemicals including universal blix.
Is using blix likely to significantly prejudice the quality of negatives compared to using seperate bleach and fix? I guess the answer may well be yes and if so can anyone recommend packs of bleach and fix suitable for low throughput amateur use - say 6 films a month? I live in the UK and have to buy chemicals by internet or phone.
Cheers
Jeff

PHOTOTONE · Jan 30, 2007

The C-41 separate bleach and fix are quite stable and have a very long life. The bleach may require oxegenating from time to time to keep its bleaching qualities. You can bubble air into the bleach from a common aquarium aeriator, while in the bottle, for a while before you use it each time.

bob100684 · Jan 30, 2007

bleach then fix......labs do it for a reason, though I forget why, but I'm pretty sure it helps to make sure your negatives last.

Mike Wilde · Jan 30, 2007

formulae attached

I use the pH given for the bleach and fix (I splurged for a pH meter for the garden, wine and beer efferts, as well as the darkroom to spread the cost guilt around many hobbies. I also home scratch mix the developers, where pH control is a bit more important.

I bleach 2.5-4 minutes in C-22 formula, just potassium ferricyanide and potassium brimide, but don't regenerate - I have tried and ended up with a gunky mess. I replenish instead - mix up two 1L batches and designate one as the replensher. I go 45mL fresh replenisher into the used solution per 36-35mm or 120 roll. I keep the overflow, and evaporate it down to a smaller volume in the spring sunshine before taking it to the hazardous waste depot along with my similarly treated used B&W fixer. When the replenisher is empty it is time to start with fresh solutions

I rinse for 30 seconds between bleach and fix.

I bleach 2.5 - 4 min in a fixer based around ammonium thio. There i not a ton of silver in c41, so it goes for a long time with the upstream rinse to protect it.

By the way, after the film is in the bleach for about 30 seconds you can do the rest in interior light. Watch and see that the film is bleached if you are worried about bromide buildup as the bleach is getting near its toss point. You can then alos be sure that you are fixing for twice the time it takes to clear.

The amm thio comes as a 60% solution usually, so it should be sourced in britain. The other chemicals are dry (save the acetic acid of sodium hydroxide you may need for balancing pH- easy to find locally) and may be satisfactorily mail ordered. I believe that Photographers formulary, and Artcraft in the USA mail order overseas; I know that JD Photochem here in Canada does. There are UK mail order houses, but I have not yet patronised them.

Photo Engineer · Jan 30, 2007

To date, no one has been able to formulate a good blix for C41 films. A couple of us have patented one formulation and I am working on another alternative.

Most blixes result in retaines silver which causes muddy colors.

PE

OldBikerPete · Jan 30, 2007

I mix my own solutions for C-41 including bleach and fix. In order to do that I had to buy a pH meter from Radio Spares (AU$135) and a jewellery scale which weighs up to 200g at a precision of 0.01g off eBay for AU$20 - plus assorted beakers and measuring cylinders. The chemicals came from JDPhotoChem in Canada by surface freight.
Formulae are published here on APUG - do a search for C-41 and you'll find those formulations and many others. The bleach I use is a modification of the one posted above by Mike Wilde. I could not get the Ammonium Bromide so I substituted Sodium Bromide and added Ammonia solution so as to get the same concentrations of Ammonium and Bromide in the bleach. In using a pH meter one also has to calibrate the meter with solutions of standard pH each time. I use the carbonate solutions at pH=7 and ph=10.2.
You can but such calibrating solutions made up if you wish - I would start by asking a pharmicist where to get them.
Alternatively, bleach and fix last almost indefinitely in storage, so why not try buying a quantity from a local developing shop with a minilab? They usually buy their chems in 5L or 10L containers - some formulations may need an 'activator' added as well.

chorleyjeff · Feb 2, 2007

Thanks for the various replies.
Seems the best solution (sorry) for me is to buy the bleach and fix in larger quantities and get developer in small quantities.
I'm not yet ready to start mixing my own chemicals again - did it 45/50 yeras ago for cheapness- but the way things are going I may well have to start again!
Cheers
Jeff

pentaxuser · Feb 2, 2007

chorleyjeff said:
Thanks for the various replies.
Seems the best solution (sorry) for me is to buy the bleach and fix in larger quantities and get developer in small quantities.
I'm not yet ready to start mixing my own chemicals again - did it 45/50 yeras ago for cheapness- but the way things are going I may well have to start again!
Cheers
Jeff

Jeff As a fellow sufferer from the U.K., I'd be interested in what sources, quantities etc you find. I don't think I have ever found a "small" source in the U.K. for separate bleach and fix. Speedibrews via Silverprint do a very small kit of 600ml which is powder so has unlimited shelf life until mixed but even that is blix and not bleach and fix. Of course it is used very quickly and I hadn't given separate bleach and fix another thought until I saw PE's comment on blix and muddy colours.

I had assumed that my colours were OK but it begs the question of how muddy they might be as I haven't any film to compare them to which was bleach and fixed as opposed to blixed.

pentaxuser

Photo Engineer · Feb 2, 2007

If you cannot get Ammonium Ferric EDTA easily, you can make a close approximation by using Ferric Chloride and EDTA, and then bring it to pH 6.5 with concentrated ammonia solution. You have to be very careful so as to prevent precipitation of Ferric Hydroxide. If this forms, the solution is useless.

Before the Ammonium Ferric EDTA plant was up and running at Kodak, I used to make my own in the lab to make up the EP3 blix.

I may have that formula around here somewhere. If anyone is interested, I would give a try at finding it or recreating it in the lab.

It is slower than the straight Ammonium Ferric EDTA blix or bleach due to the presence of chloride ions, which repress the fixation reaction, but it does work.

IIRC, you can also use Ferric Nitrate.

Powder bleaches, fixes bleaches and blixes are generally slower than liquid ones due to the use of sodium salts which slow the action of bleaching and fixing considerably over the pure ammonium based blixes, bleaches and fixes.

PE

chorleyjeff · Feb 3, 2007

pentaxuser said:
Jeff As a fellow sufferer from the U.K., I'd be interested in what sources, quantities etc you find. I don't think I have ever found a "small" source in the U.K. for separate bleach and fix. Speedibrews via Silverprint do a very small kit of 600ml which is powder so has unlimited shelf life until mixed but even that is blix and not bleach and fix. Of course it is used very quickly and I hadn't given separate bleach and fix another thought until I saw PE's comment on blix and muddy colours.

I had assumed that my colours were OK but it begs the question of how muddy they might be as I haven't any film to compare them to which was bleach and fixed as opposed to blixed.

pentaxuser

Yes the comment about muddy colours echoed what I have heard hinted at elsewhere and is an additional reason for me to do seperate bleach and fix. I have not yet looked for, say, 5 litre packs of Bleach and fix because I have some Paterson C41 and Universal blix to use up but had assumed such packs were available but now I'm not so sure!
Cheers
Jeff

rosseelj · Feb 4, 2007

Photo Engineer said:
To date, no one has been able to formulate a good blix for C41 films. A couple of us have patented one formulation and I am working on another alternative.

Most blixes result in retaines silver which causes muddy colors.

PE

PE, from your postings here and on PN, I conclude that your biggest objection against blixes is long term unstability of the solution. In other words: a blix of a few weeks old is not strong enough to remove all the silver.

But what about freshly mixed blixes? Are these strong enough to not suffer from retained silver?

Reason for asking: I'm using (Tetenal/Jobo) blix at the moment, and I have the impression that the colors are less muddy than what I got from the minilab I used before. And that was using seperate bleach and fix...

Regards,

JanR

Nick Zentena · Feb 4, 2007

Do you mean the colours in the prints or on the negatives? Minilabs to me print that way. They get the exposure a little wrong. They get the colours a touch wrong. Not enough for the average person to notice but when you make a good hand print and put the two next to each other the difference is clear. Same negatives will print much better then the minilab would.

rosseelj · Feb 4, 2007

Nick Zentena said:
Do you mean the colours in the prints or on the negatives?

It's the negatives - I do all my printing myself.

I doubted for long to develop my negatives myself. Made the step a year ago. I've ruined a few films (CD-R really ages fast in an ATL and I learned that the hard way by two completely blank films), but overall, I'm very happy with the results I get.

So far I've worked with blix. But I always do a fresh mix before each development session. Main reason is the CD-R really needs this. I also do this for blix, as I understand the two main components work against each other so the solution isn't stable.

So I'm wondering, if with this approach I have a risk of retained silver? It doesn't look like that by judging the results, but I'd like to hear some confirmation. Otherwise, I will order separate bleach and fix when I run out of my current chemicals. It's just that separate chemicals are more work and take up more space, etc... And to be economical you have to regenerate the bleach, which is again more work and more room for error.

JanR

Photo Engineer · Feb 4, 2007

JanR;

Rebleaching and refixing should clean up the colors if it is retained silver.

And, photolabs are not immune to bad bleach or fix, especially if they under replenish.

Here is the problem. If a blix is strong enough to oxidize the silver metal image in film and to get around the dye clouds and inhibitor clouds in film and get through the thick layers, it will begin to self destruct nearly as fast as it is mixed. There are several ways around this, but they are not being used in blixes for films.

For the most part, a film blix is merely a paper blix mixed up at 2x strength and that won't do the job. A film blix has to be as strong as ferricyanide bleach plus a fix (don't try this though).

But, in the final analysis, use what works. What you end up with often is something that looks like a bleach bypass film.

Even extending the process time did not work in experiments I carried out when working on the C41 blixes we tested. We never achieved the results we wanted with all of the silver removed to a satisfactory level. Usually there was quite a bit left behind.

PE

pentaxuser · Feb 5, 2007

chorleyjeff said:
Yes the comment about muddy colours echoed what I have heard hinted at elsewhere and is an additional reason for me to do seperate bleach and fix. I have not yet looked for, say, 5 litre packs of Bleach and fix because I have some Paterson C41 and Universal blix to use up but had assumed such packs were available but now I'm not so sure!
Cheers
Jeff

Jeff. I don't think I'll ever be in the business of ordering the individual chems and mixing my own bleach and fix unless it was a purely " follow these simple directions" routine as in mixing Perceptol. My knowledge of chemistry is far too ltd with little chance of improving it.

As far as finding a source, then Michael Maunder who makes up the Speedibrews kits for Silverprint might be prepared to help. However the fact that he keeps things simple in his kit instructions by pre-preparing powder for blix and not bleach and fix suggests that: either he believes the problems of blix are minimal and/or he believes that the problems and pitfalls of getting users to mix their own bleach and fix successfully considerably outweigh the subsequent (marginal?)advantages.

This of course is me second guessing the reasons for Michael Maunder not making separate bleach and fix kits and I could be wrong. I am not trying to cast doubts on PE's point.

If it is simple to obtain and mix the chems in a relatively foolproof way for bleach and fix then even if the difference in neg quality is slight but noticeable it would be worthwhile trying.

When Rayco chems went bust a couple of years ago we lost maybe the only service that was dedicated to chems and helping apprentice photo chemists to indulge in DIY.

Anyway my request still stands. Please let us know how you get on.

As a chemist I wonder how PE feels about Paterson's universal blix i.e. the same stuff for film and paper. Could there be reasons why this is not ideal either? I don't think other companies follow this practice. They have separate blixes packaged in separate kits for film and paper.

I blissfully used the Paterson universal blix and it seemed to work OK but maybe only time will tell for both my prints and negs.

pentaxuser

PHOTOTONE · Feb 5, 2007

Any deviation in the process for which the film is designed for could result in the dyes fading faster than they would if the process is kept to the original procedures and chemicals. The dyes by themselves are not very stable (my understanding) and they are stabilized during the process.

Photo Engineer · Feb 5, 2007

What I said about film blix does not apply to paper blix.

There is a review of these kits in Darkroom Techniques about 15 years ago showing what can happen with non-Kodak and non-Fuji kits. But this only addresses the developer differences. There may have been some change since then, but IDK. The small companies are notoriously lacking in R&D.

I say "use what works for you" and point out what can and does happen with a blix with films. I doubt if many could see the difference in some cases.

However, the present kit film and paper blixes are very similar except for concentration and the keeping is rather similar. It is the silver retention that is the real problem.

My suggestion is to test it this way. Take 3 rolls of C41 film under identical conditions. Run one through a normal Kodak or Fuji process and then run another through the same developer but with a blix. Run the third through the Kodak or Fuji process using bleach bypass.

The normal process is the reference, and the bleach bypass is the worst case. It will turn out, depending on kit, that the blixed film is somewhere in between these extremes.

BTW, I get no royalties on any Kodak blix or bleach. I got $1 plus "valuable consideration" for my contributions at EK. I have no commercial interest in any blix, bleach or fix at this time. I am working on a color film blix due to this very problem, but that is for the future to decide. I know how to do it, but doing it economically is the poblem.

PE

chorleyjeff · Feb 6, 2007

pentaxuser said:
Jeff. I don't think I'll ever be in the business of ordering the individual chems and mixing my own bleach and fix unless it was a purely " follow these simple directions" routine as in mixing Perceptol. My knowledge of chemistry is far too ltd with little chance of improving it.

As far as finding a source, then Michael Maunder who makes up the Speedibrews kits for Silverprint might be prepared to help. However the fact that he keeps things simple in his kit instructions by pre-preparing powder for blix and not bleach and fix suggests that: either he believes the problems of blix are minimal and/or he believes that the problems and pitfalls of getting users to mix their own bleach and fix successfully considerably outweigh the subsequent (marginal?)advantages.

This of course is me second guessing the reasons for Michael Maunder not making separate bleach and fix kits and I could be wrong. I am not trying to cast doubts on PE's point.

If it is simple to obtain and mix the chems in a relatively foolproof way for bleach and fix then even if the difference in neg quality is slight but noticeable it would be worthwhile trying.

When Rayco chems went bust a couple of years ago we lost maybe the only service that was dedicated to chems and helping apprentice photo chemists to indulge in DIY.

Anyway my request still stands. Please let us know how you get on.

As a chemist I wonder how PE feels about Paterson's universal blix i.e. the same stuff for film and paper. Could there be reasons why this is not ideal either? I don't think other companies follow this practice. They have separate blixes packaged in separate kits for film and paper.

I blissfully used the Paterson universal blix and it seemed to work OK but maybe only time will tell for both my prints and negs.

pentaxuser

Did a Fuji 1600 35mm and 100 MF roll sequentially in the same 500cc of Paterson C41 and Universal blix using boiled and filtered water for mixing and washing.
The negs look nice and clear but shall not be able to print for a couple of weeks. Although the instructions suggest each 100cc of working strength dev will develop one film (ie 5 films in 500cc) I have kept to the 2 films which maybe a safer option - but brings the price to labs like Peak Imaging which, of course, begs another question.
Cheers
Jeff

rosseelj · Feb 7, 2007

Photo Engineer said:
There is a review of these kits in Darkroom Techniques about 15 years ago showing what can happen with non-Kodak and non-Fuji kits. But this only addresses the developer differences. There may have been some change since then, but IDK. The small companies are notoriously lacking in R&D.

PE

The blix I'm using doesn't come out of small "home" kits. It's the Jobo/Tetenal blix that is used in both their 3, resp. 2 bath E6/C41 processing aimed at the professional market (ATL machines). Given that both Jobo and Tetenal are respected companies of a decent size (Tetenals production volume is roughly that of FujiHunt), this should maybe give a better guarantee than the much smaller producers.

But given PE's explanation, I'll probably go for the separated bleach and fix. Main problem is now to decide what to buy. Goal is to have minimizing shipping cost. I'm thus looking at the smallest packages, and thes are the LR bleaches that replenish at 5ml/m of 135 film. That's a very low replenishment rate, but this should be no problem given that the lifetime of bleach is roughly infinite.

Question back to PE: is a starter for these LR bleaches really necessary?

JanR

Photo Engineer · Feb 7, 2007

No starter is needed for a bleach or blix.

PE

rosseelj · Feb 8, 2007

Photo Engineer said:
No starter is needed for a bleach or blix.

PE

Given that bleach works to completion, this makes sense. Which leaves me wondering: why do Kodak, Fuji and other then sell bleach starters?

Photo Engineer · Feb 8, 2007

For preseasoning in replenished processes.

PE

Blix or bleach and fix for C41

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