Dichromates ???

Hi,

I've been reading the list for the last few days about dichromate
sensitisers used in a few of the alt-process like carbon printing for
example.

This is probably dum on my part but anyway, here it is: at what point a
dichromate solution becomes photosensitive (UV)? I'm just curious, I'm sure
it will work but I can't help myself.

I ask this because I just got my potassium dichromate and the container is
not light tight and this mean "UV" could affect the crystalls in some way
because "UV" are present at various levels in practically all (many) light
source. I assume something must happen when the crystals are dissolve in
water until the time they get dry for this process to work.

I wonder also if other frequencies of the spectrum, radioactivity or just
plain heat could affect the solution. I find it hard to understand why the
dichromates have a tendency to fog (based on many post I saw) if nothing
special happens when they are dry, assuming of course the solution is kept
in the dark or "UV dark".

I have many more dum questions like this one, I hope you'll forgive me.

Thanks for your time
Yves Gauvreau, Montreal
Received on Wed Nov 9 13:27:54 2005