Re: Sodium Palladium Chloride for toner

Sandy,

I assume your comments here on bleaching and selenium are partly
influenced by the VDB toning discussion going on over at APUG. As a
result of those conversations, yesterday I started running some tests
with Polytoner and gold toner. However, since I was at work at the
time, students distracted me in the middle of the test and I ended up
inadvertantly toning with Clerc's Gold Toner and also Polytoner before
fixing.

What I observed was that the Polytoner 1+4 fogged the VDB and that there
was some bleaching with the gold toner that I had never noted before
when I tone after fixing. The resultant color of the gold-toned print
was almost purple rather than a purplish-brown. (Could be that added
efficiency you speak to but I should also mention that I kicked the
toner up a notch with additional gold chloride since a student had
previously reported the toner was exhausting and taking a long time to
work. I didn't mix fresh toner nor test it before I pumped it up
because school was closing early for the Thanksgiving holiday and I had
a limited time to test this stuff.) When I return to work Monday I plan
to mix fresh toning chemistry and run several tests including the
effects of Polytoner at different dilutions, KRST at 1+500 as suggested
over at apug.org, and Clerc's toner mixed fresh. I'll do the tests
against a control untreated VDB and also test the effects of the
previous when applied before and after fixing.

FWIW, I'm using Cranes Kid Finish ecru and I adopted your suggestion of
an initial citric acid bath with VDB about a year ago. I'm using a 2%
citric solution followed by a 3 minute wash, fixing in two successive 2%
sodium thiosulfate baths for 1.5 minutes each, washing prints for 5
minutes then toning by inspection followed by hypo clearing agent for 3
minutes and a 30 minute wash. Since adopting the initial citric acid
bath, I see very little change in density throughout any of the wet
steps although the prints do dry down a bit. If anything, I'd say the
prints actually gain a bit of density when immersed in the thiosufate.
I'll actually keep notes on the shifts for a change next week.

Thanns for the info and have a Happy Thanksgiving.

Joe
___

>>> sanking@clemson.edu 11/24/05 10:32 AM >>>
Joe,

If you tone before fixing the the action is faster and and more
efficient. Also, toning before fixing almost entirely eliminates
bleaching of the print during fixing.

Just make sure you give the print a good wash in pH neutral or
alightly acidic water before toning.

And don't even think about toning with any selenium toner before
fixing. If you do there will most likely be staining.

Sandy

> >>> sanking@clemson.edu 11/24/05 9:19 AM >>>
>>>...Just remember, when toining with gold, palladium or platinum tone
>vandykes *before* fixing.<<
>
>
>Sandy,
>
>Why do you recommend toning with these before rather than after fixing?
>
>Joe
Received on Thu Nov 24 10:21:45 2005