RA-4 precipitate issue

[Sue Earle]

I work in the Photo Dept. of an art school and we have been using a 32 inch Hope RA-4 paper processor for several years without incident. We have always used Kodak RA-4 chemistry kits exclusively in this machine.

In November we had an incident where the developer tank and rack became coated with a very thick tar-like substance. We clean the racks weekly and are accustomed to the small amounts of tar that build up on the rollers but this was much thicker and slimier than normal. We suspected bleach in the developer as the culprit.

We addressed the situation by draining the developer, thoroughly cleaning the tank, replenishment system, and racks, and then mixing a fresh batch of chemistry to fill the tank. In February the goo returned and this time the white of the paper was coming out blue. We repeated our decontamination process.

It's been 2 weeks since that happened, and today when we opened up the machine for its routine clean, the developer tank and rack were coated with a slimy WHITE substance.The machine has been producing perfect prints, despite the precipitate.

So what the heck is going on? Can anyone shed some light?

 

[Ian Grant]

Have you recently changed the type of Kodak chemistry you use ?

I ask because I used to do a lot of site visits to processing labs and I know Fuji wouldn't honour the warranty of their Frontiere machines if certain makes of chemistry were used. Some people assumed this was to force users to buy their chemistry but I worked with one major chain of UK labs and they had huge and costly problems with one or two third party developers, and will now only use Kodak or Fuji.

Ian

 

[Sue Earle]

No, we're using the same Kodak RA-4 kits we've been using for years. Nothing has changed at all! We did notice that Kodak has changed the packaging on their solutions and wondered if maybe they've been monkeying with the formulation a bit.

 

[Ian Grant]

You should contact Kodak, they may have an answer.

Ian

 

[Photo Engineer]

Sue;

AFAIK, the formulas are the same. Black goo indicates severe developer oxidation. The goo can be dissolved with an acidic solution such as citric acid in water. Blue whites sometimes indicates fogged paper, but can also be bleach in the developer. The white material I cannot figure out except that you can get a white precipitate or sludge in heavily exhausted blix.

EK has very good customer service. Give their toll free # a call and ask them.

PE

 

[Richard Harris]

PE,
I have posted today a reply to this question on photo.net and I am interested on your citric acid thing. I guess this is to clean the tanks yes? not to dissolve the tar in a working solution.
Sue,
are you sure you are using RT roller transport chemicals these have the extra anti oxidants. Fuji and Agfa are better for avoiding tar build up I believe but this is anectodal for me as I don't use kodak developer just their blix.

 

[Photo Engineer]

The Kodak developer used 2 antioxidants in it that effectively prevent oxidation and tar. The tar is oxidized developer and is a mildly basic organic goo. Acid will assist in dissolving it. To test this, you can use either acetic acid 28% or Citric Acid, either of which will dissolve the goo. Just take a small amount of the goo and put it into some acid solution. It immediately turns the acid black or brown and dissolves in the acid.

I used to use dilute sulfuric acid, but then I wore a lot of protective equipment so I don't suggest that you use it. I used about 10% sulfuric, which is way to strong for most uses.

PE