Re: Toning kallitypes and vandykes

The replacement of silver with palladium ranged from less than 20% at
2.5 minutes to approximately 60% at 20 minutes.

I would like to find a way to accelerate the process to reach about
90% in 10 minutes.

Sandy

>...what was the percentage of replacement after 20 minutes, if you
>don't mind me asking? 50? More than 80? Close to 100?
>
>~m
>
>----- Original Message -----
>From: <mailto:sanking@clemson.edu>Sandy King
>To:
><mailto:alt-photo-process-l@sask.usask.ca>alt-photo-process-l@sask.usask.ca
>Sent: Sunday, November 13, 2005 10:26 PM
>Subject: Toning kallitypes and vandykes
>
>I posted the following message over on apug.org but so far have
>gotten zero response. Hope someone here can offer some advice.
>
>Basically the situation is this. I interested the folks in
>photographic conservation at the Getty with the issue of toning
>kallitypes with pallaidum and platinum, specifically. Preliminary
>spectra analyis in their lab has confirmed that toning a kallitype
>(and I believe the same would apply to vandyke) with palladium or
>platinum results in replacement of the silver by the more noble
>metal, adding much permanence to the print.
>
>The toning formula used for the tests was 5 grams of 20% palladium
>chloride solution plus 5 grams of citric acid in one liter of water,
>and I did toned 5X7 test samples for 2.5, 5, 10 and 20 minutes,
>using just enough of the toner to cover the surface of the print in
>flat bottom tray. That turns out to be about 50ml of solution for a
>5X7" print.
>
>What the tests showed was that the efficiency of toning in terms of
>the percentage of replacement of the silver with palladium is time
>dependent, i.e. a toning time of 20 minute results in a much higher
>percentage of replacement than toning for 5 minutes. This leads me
>to a question that I hope some of the chemists on the list might be
>able to answer. Does anyone have any idea how I might adjust the
>toning formula formula above to make it faster acting?
>
>Sandy
Received on Mon Nov 14 09:52:17 2005