Making RA-4 Chemicals Last Longer

[Chris Douglas]

I have read several threads that say Blix is not very stable or long-lived. I notice in the MSDS for Arista kits that Blix part-A is ammonium thiosulfate and part-B is ferric ammonium EDTA. Has anyone tried using them un-mixed as separate bleach and fixer? Seems they would last the normal shelf life if not mixed together. Second question, my current blix is a couple months old and sulfur has precipitated out. Can I still use it as bleach, and follow up with conventional ammonium thiosulfate fix?

 

[Photo Engineer]

If sulfur is pptg out, don't use it. The blix can cause white spots in the paper and can also fail to bleach properly.

You can use it as 2 parts with longer life but you will probably have to use 2 minutes bleach and 2 minutes fix. Also, you will have to put a 2 minute wash between the two. This is all in order to both bleach and fix, and also to preserve the lifetime of the separate fixer which would suffer from carryover otherwise.

PE

 

[kb3lms]

That's very interesting. I've also wondered about using Part B as a source of FeA ETDA for other uses, although I don't know how well that would work as there are other ingredients, acetic acid, I think. I am using the Kodak chemicals so not sure if they are the same as the Arista. I bought the 10 liter size and I am thinking that I could use some for another project, especially if the fixer part is really just fixer?

As for life of the working solution, I have been mixing up a liter at a time. I'm about to dump my first liter, but I have been using this one for a month. I keep it tightly capped in heavy PET bottles (PowerAde quart) and keep the bottles in a large ziplock plastic bag on a cool, dark shelf. I have had no problems or change in results, but the developer is down to about 3/4 of it's volume, getting dark looking, and some dirt so time to go.

I have also noticed that Kodak Edge paper changed the color of the developer and stop, probably from the pink dye overcoat. Fuji CA did not seem to do this, although the Fuji is coated light blue. The color change didn't seem to affect anything.

YMMV

 

[Chris Douglas]

PE,

Thanks for the straight answers. I am struggling to become a better amateur photographer, but I also enjoy the chemistry and being a technical practitioner. I can't find ferric ammonium EDTA, do you know of a source. Photo Formulary said they couldn't find a reasonable source. Thanks again.

Best regards,
Chris

 

[Photo Engineer]

I got my NH4FeEDTA at the Formulary, so I guess if they cannot get it, we are stuck. It was not exactly flying off the shelf last time I ordered some.

Try KYANTEC chemicals or ESP chemicals.

PE

 

[mts]

Also look for the sulfate of NH4FeEDTA. You must use a larger amount adjusting for molecular weight but the dry chemical can be shipped without surcharges that apply to the liquid form. Sadly, I too have not found a source for either.

 

[hrst]

I've had absolutely no problems with Kodak RA-4 blix even 8...9 months old and used. Stored in squeezed PET bottle. The same goes with developer. It may be very dark, deep red, even a bit dirty, but still working perfectly! Most of the color of used developer is dyes from the paper anyway. You can see the effect if you prewash your papers, the water gets pink quickly.

Tetenal monoconcentrate blix didn't work that long, even when it was good when freshly mixed. I had the precipitation in just a few months, sometimes in just a few weeks, and sometimes it was dead to begin with. Don't know about Arista...

 

[Photo Engineer]

Also look for the sulfate of NH4FeEDTA. You must use a larger amount adjusting for molecular weight but the dry chemical can be shipped without surcharges that apply to the liquid form. Sadly, I too have not found a source for either.

This is new to me. It can cause problems due to swell inhibition.

PE

 

[Mike Wilde]

I have bought the Kodak RA-RT developer, and two part Blix for my RA processing (apart from my mix from scratch experiments). The Blix from the wholesaler came as a A+B to make 40L, and it was only sold by the case. One of my 4 B bottles of ammonium thio sulfated out, and I have made up a replacement from a formula that Francis Miniter posted on rec.photo.darkroom many years ago, when his fixer component went south. It has worked just fine.

Sorry to hear of the demise of avaliable supplies of Ferric Ammonium EDTA. I ordered about 1.5L of the stuff from Johnny back when he was still running JD Photochem. Sadly, Claire, his sucessor, has since shut the company down. They gave such great service to me.

I still have about 1L, but it does not get used often, since the commercially mixed blix concentrates work fine for me.

I also was lucky enough to have 30L of new e-6 bleach concentrate turn up on the free to reuse shelf about a year ago at the HHW depot when dropping off spent fixer. I now use it for my E6 and C-41 bleach needs. When that is gone I will go back to my home mixed c22 bleach.

 

[EdSawyer]

RA-RT

I use Kodak RA-RT also, and it seems to last quite a while, I haven't exhausted it yet. I run it as a replenisher in a Fujimoto CP-31, and even turning the replenishment way down (2 out of 7 on the dial) it still seems to be doing fine. I mix it in 10L batches and store it in Doran floating-lid tanks. Offhand I estimate I am getting about 35 8x10 or 8.5x11 prints per liter of replenisher, which is about 28ml/print. I could probably crank it down a tiny bit more and still be ok.

FWIW
-Ed

 

[Chris Douglas]

Okay, looks like Formulary ferric is available through B&H, but expensive. I guess Kodak chems are the way to go, but sorting out the different types is confusing. I will look through the threads to see if instructions are available for someone who has only used kits. Thanks for the comments and help.

 

[brucemuir]

Chris
I'm using this
Dead Link Removed
and
this
Dead Link Removed

from Adorama (they WILL ship)
I'm using it in trays at room temp down to 64 f without any problems.
This method needs no starters and 10L of each will last me awhile.

 

[Chris Douglas]

Bruce,

Thanks for the info, I will definitely try these out.