Bleach not Blix RA-4

[Particle Accelerator]

I've done a lot of looking and have found much discussion but no formula for using a separate bleach and fix instead of an RA-4 Blix. Since separating the two makes for a very cheap long lasting bleach why not do it? However I have not been able to find a correct formula or time for room temperature tray development. Farmers Reducer has many proportions and I would like to feel secure that I am not shortening the longevity of my prints. I imagine the fix would be a paper strength rapid fix for 2 min. at 68 F ?

 

[Photo Engineer]

If you use part A and part B of the RA4 blix they make a good bleach and fix individually. Use 2 minutes for each with a wash in between for best life.

PE

 

[Ian Grant]

Not sure why you really need to separate the step into two. There's not much silver in RA-4 papers and the Blix keeps reasonably well and isn't expensive. Don't by amateur kits get Minilab packs, far cheaper, many stores split multiple packs for home use. This is why Champion/Kodak dropped a lot of amateur packaged chemistry.

So why mess about using a Ferricyanide/halide bleach and then a separate fixer ?

Ian

 

[Particle Accelerator]

I don't know how long Blix lasts in a tray. I don't know when I might be underfixing. So I read while researching apug from a fellow who suggested separating the two. That way you get a cheap bleach that lasts and lasts, and your fix is always that days fresh mix. And much cheaper than buying RA-4. Together the exhausted fixer renders the blix unusable. I believe PE once said 4 hours in the tray was the limit, and that just doesn't seem cost effective. Maybe he just meant the developer.

 

[Photo Engineer]

PA, tray life depends on the blix, the temperature and the usage as well as work flow such as use of a stop bath, use of a drum and etc. The current blix can be used as 2 parts as I stated above, with 2' bleach, 2' wash and 2' fix at 20 deg C. Use a 4' - 8' wash at about 20 - 30 C afterwards.

PE

 

[Particle Accelerator]

I currently tray develop using RA-RT at 68 F , and use 2 liters at a time. I use a citric acid stop bath. After about six hours I usually have about 40 8x10's. The developer is then tossed. What condition is the blix in? People talk about storage life, and reuse, but I have no idea if this solution is now capable of proper functioning. If on the other hand I mixed the correct amount of Farmers Reducer for the paper, I could reuse this indefinitely, and then simply mix fresh fixer for the next go round.

 

[Photo Engineer]

I have been told that a Citric Acid stop is not good with color products. I have not investigated the reasoning, as a Citric Acid stabilizer was once used, but it was preceded by an acetic acid stop. So, just leave it as an unconfirmed comment here.

Farmer's reducer does not enter into any of my comments.

A Ferricyanide bath of any sort should have a Sulfite containing clearing bath before use and after use to prevent stain and prevent contamination and destruction of the fix. Ferricyanide reacts with color developer to form dye as a stain unless an excess of Sulfite is used beforehand. It harms fix if not cleared with Sulfite afterwards.

Ferricyanide can oxidize the incorporated dye stabilizing agents as well. IDK regarding new stabilizers, but that was considered to be a possible outcome when I worked on them.

PE

 

[Particle Accelerator]

How much ferricyanide per liter and are there any other chemicals added to that bleach formula? Any idea of the capacity of blix in trays, hours, and amount of 8x10's. And if A and B are separated, does that extend the use considerably? Thanks for the heads up on the citric acid. I never would have thought that an issue.

 

[Particle Accelerator]

Sorry to persist PE, I know you have written a library on blix, because I have read a good portion of it, but I have never yet found a firm number of print capacity for this solution. I have also after a weeks worth of photo.net, and elsewhere not been able to get a formula for a ferricyanide bleach for color paper. People respond with all kinds of things but almost never the original question. Funny. I've gotten entire lectures on color dynamics, removing gases, measuring ph, on and on, but never the answer to the original question. I wonder why this is?

 

[Photo Engineer]

I do NOT recommend a Ferricyanide bleach for RA4 paper for the reasons stated above.

However, if you insist, here is one:

Water 1 L

NaNO3 28.5 g
KeFe(CN)6 16.8g
KBr 5.47 g
Boric Acid 2.75 g
Boric Anhydride 1.54 g
Borax 5M 3.33 g

pH to 7.40 at 20 deg C

This may disturb dye stability and may cause severe stain if not used with a clearing stop bath and clearing post rinse before the fix step.

As for the RA bleach as parts A and B, the clear part will keep just like any hypo and goes bad at about the same rate as any hypo solution or concentrate. The red part really does not go bad at all. Exhaustion is about the same for the fix as a B&W fix, and the red part (bleach) has about the same capacity as the fixer. These are given on the Kodak web site. I think you should get the exact figure there.

PE

 

[Particle Accelerator]

Nix to the ferricyanide then.
So the bleach even separated in use has the same capacity as the fixer? That contradicts my entire assumption, which was that merely separating these resulted in a longer lasting bleach, which also availed the option to use an ordinary fixer, without the Ferric Ammonium needed for the combination.

 

[Photo Engineer]

You are misunderstanding me.

Longevity and capacity when talking about photographic processing solutions are not the same thing. Longevity is how long something keeps, but capacity is how much it can be used. The two parts here (Blix A and B) kept apart have longer longevity than they do when mixed together. They have approximately the same capacity mixed or separate, but the exact figures are on the Kodak web site.

PE

 

[Particle Accelerator]

My apologies if I am misunderstanding. I have not inquired about longevity of solutions stored. In oxidizing trays yes, but not stored in bottles. Capacity has been my principal interest. Many statements made repeatedly on apug have indicated to me that bleach lasts a long time, and that blix got the early toss because combining bleach and fix resulted in much earlier exhaustion, therefor I simply reasoned as I did. Separate the two. All one had to lose was a little time, while gaining economically. Repeated use of the bleach and a much cheaper fix.

 

[Photo Engineer]

The Kodak and Fuji RA blixes have been formulated to be the most stable possible mixtures of oxidants and reductants. That is about the best I can say at this point.

PE

 

[Particle Accelerator]

Blix was formulated for roller transport, as we know you well know. For home darkroom, especially using trays, a benign stable bleach formula, and plain fix makes more sense, to me.

 

[Photo Engineer]

I formulated and used that original blix in trays at home in the late 60s and early 70s. It was formulated to work in trays, baskets and roller transports as well as drum processors and others on the market then. The original formula at work was formulated using large glass or plastic cylinders with hangers. It was then tested in our Calumet basket processor and the large Pako paper processing machine.

PE

 

[Particle Accelerator]

Of course it works in every conceivable situation. But why should I have to buy a packaged substance when a few dry chemicals would do the same job.? That is if a benign and stable bleach can be made without the drawbacks of the ferricyanide you mentioned.

 

[Photo Engineer]

If it works, use it. I gave the Ferric EDTA powder version here a few weeks ago.

PE

 

[Particle Accelerator]

Ferric EDTA is nearly impossible to obtain in the states. China and India want to sell it by the hundreds of pounds. Art Craft, Art Chemicals, and Formulary cannot obtain it.

 

[Photo Engineer]

My formula made the Ferric EDtA from the dry chemicals, ie, Ferric Chloride and EDTA + Ammonia.

PE

 

[Particle Accelerator]

Great, I'll look for it then. Thanks for your help.

 

[hrst]

I have never had Kodak RA-4 blix go bad. Tens of hours in open trays, and reusing for months - no problem. I just make a new one when I feel that I have reached the maximum capacity or if much more than 6 to 9 months have passed.

I'd suggest you use the normal procedure. Then, IF you have any problems, you can try something else.

However, I have had problems with Tetenal RA-4 blix. Don't buy anything that is mixed together on the plant, if you cannot confirm you can buy it very fresh (a few months old max). The blix must have parts A + B that are mixed by the user. Then the shelf life is something like 6 months, or even more if you are lucky.

 

[amateur_trombonist]

Using RA-4 compatible Bleach/Fix (Blix) in a divided method

If you use part A and part B of the RA4 blix they make a good bleach and fix individually. Use 2 minutes for each with a wash in between for best life.

PE

This is great news - I mixed up an entire 10 litre kit of the Blix. I had to set aside darkroom activities for about a year. When I used brand new developer I got a cyan/green border on my prints. I had been under the impression that Blix basically did not go bad. Maybe my offwhite borders has been a Blix problem all along. I'm careful to fully rinse my drums with water before pouring in the Blix.

One question - if I only want a litre of bleach and a litre of fix do I use 1/10th of the component and add water to make up a full litre?

 

[Bob-D659]

If you are talking about liquid concentrates, yes.

 

[Photo Engineer]

If you have a 4 liter RA-4 blix kit, then this will make about 3 liters of bleach and 3 liters of fix. This does not work for film. For film, you would only get about 2 L of each when properly diluted, and you would have to add EDTA to the bleach and fix. Well, strictly speaking if you see any yellow stain in your prints or film, you would need to add more EDTA to both.

For use with film, you would have to add about 50 - 100 g/l of Ammonium Bromide to the bleach part, and the times would have to be about 8 minutes in each bath. The film is based on 100 F for film and 68 to 100 F for paper.

PE