Re: cleaning fiberglass print drying screens

From: Stephen Tucker <digitalneg@hotmail.com>
Subject: cleaning fiberglass print drying screens
Date: Tue, 25 Nov 2003 10:05:07 -0500

> I would like to use my fiberglass print drying screens that have been
> sitting around un-used for some years. Even though I always washed my
> prints thoroughly in the past, how can I clean/wash the screens to be sure
> that no chemical contamination exists?

Use HE-1 type "hypo eliminator" that chemically oxidises thiosulfate
to sulfate state, which is relatively harmless. One nice thing about
this option is that all the oxidizing agent is volatile, so there is
no worry for harmful solid residue. Some people use household bleach,
but this must be thoroughly washed out, though it's always a good idea
no matter which agent is used. I'm more curious how sodium
percarbonate products (like Oxyclean) can be used to destroy
thiosulfate in darkroom cleaning... I have a big pail of it but I
haven't tested it yet.

--
Ryuji Suzuki
"Reality has always had too many heads." (Bob Dylan, Cold Irons Bound, 1997)