T55 Se toner, was RE: POP process

> -----Original Message-----
> From: Richard Knoppow [mailto:dickburk@ix.netcom.com]

> Kodak T-55 is a type of Selenium toner made with Sodium
> Sulfide. Some of the toning comes from the sulfide.

Richard,

I do not believe that is correct, (unless boiling the stuff turns the
sulphite in Sulfide)

Anyway the recipe for T55 is:

Selenium toner bath Kodak T55 formula :

hot distilled water: 700 ml
anhydrous sodium sulfite : 150 g
selenium ( pulver) : 6 G
ammonium chloride :
 190 G
 
water to make : 1000 ml
 Add selenium and let boil 30 min. Filter to eliminate the residues, let
cool and add ammonium chloride. supplement with cold water to make one
liter.
For the use, a volume of this solution is diluted with 5 volumes of water.
The phototype is immersed lO to 15 min (@ 20°C), then washed carefully
according to the conditions indicated in the preceding lines.

Liam Lawless reported an adaptation, since he (and I also) could not get all
selenium in solution:

I quote Liam:

>>>>>>>>>>>>
Hi All,

Selenium is extremely nasty stuff that many photographers won't even touch;
I believe it's safe enough at room temperature (with skin contact avoided),
but a boiling solution does give off toxic fumes. I make mine in the open
air, usually 25 litres at a time, in an aluminium "Burco" boiler (which, I
understand, was used in the old days for cleaning dirty nappies/diapers).
The toning solution attacks other metals, so I've had to replace the tap
with a nylon one from a home-brew shop.

The published Kodak recipe (T-55 or T-56, I forget which) contains about 6g
of selenium per litre, but I could never get it to dissolve completely, even

with boiling for an hour. I don't remember the Kodak formula exactly, but
I've modified its quantities as follows. so that the selenium should
dissolve fully in less than 30 minutes:

Sodium sulphite 140g
Selenium powder 5g
Ammonium chloride 140g
Water to 1000ml

Dissolve the sulphite in hot water, bring to the boil and add the selenium.
Boil for as long as necessary, then stir in the amm. chloride. Kodak said,
I think, that the solution should be cool before adding the amm. chloride,
but it dissolves much easier in warm/hot and does not seem to make any
difference. The toner is then diluted 1+5 for use, at which strength its
action is roughly equivalent to Kodak Rapid Selenium at the 1+3 dilution.

Maybe selenium came in a different form in the 60s and further back (which
Clerc appears to confirm), but you're not alone in finding that specified
quantities do not always dissolve completely. I once tried to speak to
someone at Kodak about their selenium recipe, but they knew nothing about it

and denied it was one of theirs. If I got that in writing, maybe I could
patent it...

>>>>>>>>>>>>>>>>>>>>>>

Best,

Cor
 
Received on Tue Nov 9 05:46:52 2004