>As my pt/pd prints dry, a dusty white precipitate forms on the surface of the
>paper.
>I print on Arches Platine, develop in potasssium oxalate with sodium dichromate
>as a contrast agent, and clear in a 1:2 solution of Kodak Hypo-clear.
> The prints are washed in an archival washer for @45 minutes.
>The municipal water supply here is notoriously "hard"; faucets and shower doors
>have lots of mineral deposits.
I live in an area where the water is so hard that even the remaining HCl at 1 %
used to clear a platinum print was sufficient to precipitate the chalk in the
wash water enough to jam the plug hole but i have never had deposits on my
prints.
The difference between Tom's practice and mine is that I never use chemical
contrast controls or Hypoclear
and I wash leach my prints for from 40 mins to eight hours. I would suggest that
Tom's prints are not cleared or washed enough. Use three baths of EDTA then the
Hypoclear and wash gently in ordinary water for eight hours. Also avoid using
contrrast control chemicals.
Terry King
I could mix developer and clearing solutions
with water processed through a small reverse osmosis system (today's project),
but would still need to rinse and wash with tap water.
Though it's hard to be sure, I believe that on darker areas of the prints a
slight whitish cast can be detected before the prints go into the washer.
Any ideas? Thanks in advance.
Tom Hawkins