RE: Iron

The study in my review paper was about treatment of inked paper in
aquaous solution of EDTA, without any attempt to remove iron from the
paper. I know that the iron's catalyst action is potentiated by EDTA, if
both iron and EDTA are present in the system. However, what you are
talking about is slightly different. If your clearing is so thorough and
leaves no or insignificant amount of iron in the paper, or EDTA is also
washed out, then EDTA should not harm the paper. Whether this is
something of a concern in practice is UNKNOWN until tested.

At this point I don't know what to say. Issues in paper conservation are
interesting to me, as I use paper to make prints and I am also
interested in bookbinding. So I plan to gather more info on the past and
current research on this issue, but I do not currently practice any iron
based process (I'm strictly silver-gelatin at this point) so I can't run
even a simple test myself. Maybe I should get kits for Kallitype and
Argyrotype, but I'm so set up with silver gelatin (for example I have
emulsion making setup and two enlargers, but I have no contact printing
frame or UV light) so I can't do much in this area myself to give you
more realistically relevant answer.

On Mon, 27 Mar 2006 09:50:07 -0600, "Eric Neilsen"
<e.neilsen@worldnet.att.net> said:
> Ryuji, Does the reading that you have done then suggest that use of an
> EDTA
> clearing bath would not good? One reason that I switched to using it
> years
> ago, was that it left the paper feeling better. The acid washed paper
> felt
> stiff or brittle. Which is worse for paper, residual acid or iron? Both?
> And
> is it a specific EDTA? I have started with di sodium for bath 1 and then
> switch to tetra as the clearing proceeds. Would a pH change slow the iron
> from reacting?
Received on Mon Mar 27 13:44:30 2006