Re:selenium

Richard Sullivan (richsul@roadrunner.com)
Sun, 29 Jun 1997 19:48:24 -0600

<x-rich>>At 15:24 -0600 on 6/29/97, Richard Sullivan wrote:

>

>

>

>> Hot water 700 cc.

>> Sodium sulphite 150 g

>> Powdered selenium 6 g

>> Boil until dissolved. Cool to 65 deg F and add while stirring

>> Ammonium chloride 190 g

>> Add water to make 1000 cc.

>> <<<< end message

>

Maxim Muit says:

> Dick,

>

> You can add 5-6 grams of selenium powder to a 10% solution of

>sodium sulfide and make a toner. But this one is used with silver gelatin

>prints, it may work with VDB. According to my source (the OLD Focal

>Encyclopedia of Photography), thiosulfate is added to the above to prevent

>staining. They suggest 3 parts of above to 20 parts of a 15% solution of

>sodium thiosulfate. But of course, you are trying to avoid the use of

>thiosulfate.

Interesting. I wonder what else may inhibit staining? Something to slow down the reaction? Potassium bromide? It does in mercury toning VDB's? Or is the staining some silver kicked out by the toning process? Citric acid?

Time for a little old time photo chemistry --- start dumping stuff!

No harm in trying.

Dick

<center>

Bostick & Sullivan

Http://www.bostick-sullivan.com

505-474-0890 FAX 505-474-2857

</center>

</x-rich>