Re: Iron and paper life

Thanks,

http://www.knaw.nl/ecpa/ink/inkcorrosion.html

linked from the suggested page contained a concise account of the
problem. It is very similar to great many oxidation problems we know
that involve air and iron, including food going rancid, and probably
ascorbate developers dying suddenly, etc., possibly including humans
getting old. One of the research linked from there used salts of phytic
acid to inactivate iron catalysis. This is one method I've also tried in
ascorbate developers. However, phytic acid is expensive and not very
suitable for production use. I've found a very cheap way to largely
inactivate iron catalysis in ascorbate developer solutions, and this may
be useful in treating papers as well, if such treatment is indeed
necessary.

What we should do is to subject sample pieces of Kallitype and
argyrotype to some of the accelerated tests used for paper base with
iron ink to see if there is any significant difference. This is the
paper test part. If we read the paper-ink literature very closely, we
may be able to find existing evidences that allow us to guess what level
of iron is harmful, for example, and then test the residual iron level
in iron process print papers. This may be easier.

There should be another test to compare the difference in the
vulnerability of the silver image between the two processes. This is
already described here a few days ago.

On Sun, 26 Mar 2006 16:27:47 -0500, "Michael Hopper"
<mikehopper@rogers.com> said:
> Iron salts are the major cause of the "corrosion" of paper that results
> when
> using Iron Gall Inks. See the site
>
> http://www.knaw.nl/ecpa/ink/ink_chemical.html
>
> for many more details. Citations to many papers on the topic are found
> elsewhere on the site.
>
> Mike
>
>
> ----- Original Message -----
> From: "Ryuji Suzuki" <rs@silvergrain.org>
> To: <alt-photo-process-l@sask.usask.ca>
> Sent: Sunday, March 26, 2006 3:36 PM
> Subject: Re: An exchange with Mike Ware (on Argyrotype)
>
>
> > Well, the important part is to test whether iron is indeed involved in
> > degradation of image, paper or both. If the answer is affirmative,
> > then we should develop a way to thoroughly wash out iron, inactivate
> > its catalyst action, and so on. It makes most sense if we know what
> > the weakest part is, and remove that weakness. Firing shotguns is not
> > the best approach.
> >
> > Mike Ware's reply mentioned that iron-generated hydroxy radicals are
> > serious threat to conservation of paper. Does anyone have specific
> > references to such studies? (I don't use iron in my process, and I'm
> > not familiar with this area.)
> >
Received on Sun Mar 26 15:57:27 2006