White Precipitate Update

jcmjohn@ix.netcom.com
Mon, 23 Sep 96 19:01:19 GMT

You guys are answering questions I didn't know I had yet! Seriously, thanks
for saving me from some future headaches...this list is an outstanding resource.

I installed some water filters (carbon and sediment) this weekend. This
probably won't solve the mineral content problem, but it makes me feel better
abot what's coming out of the faucet. I've also installed a reverse osmosis
filtration system and, after some testing, will use this water for mixing
developer and clearing agents.

As a test, I soaked a few of the precipitate-covered prints in trays of
distilled water and all of the deposits were removed! This may mean that the
chemistry should be mixed with distilled rather than water from the reverse
osmosis system,and/or that I should be rinsing in distilled water between all
steps in the developer/clearing process. I'll be running a few tests to see
which technique provides the most satisfactory results. In any event, it has
become obvious that plain tap water has a mineral content too high for the
mixing of chemistry to be used with Platine. It's interesting that this
problem has not manifested itself with other papers.

Thanks again for the information on clearing agents...by the way, EDTA was a
big topic of discussion on a talk show of O.J. talking heads that I had the
misfortune of hearing over the weekend. Seems like there was some found in a
blood sample at the scene. Isn't chemistry excellent?

Thanks,
Tom Hawkins