[Table of Contents] [Search]


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [BKARTS] Deacidification, etc.



I suppose the gist of my question was more rhetorical-   I'm well aware
of concepts of pH, alkalization, deacidification, etc. (years of
Chemistry, then grad school for conservation, then work in a research
lab...  Obviously though, we don't all supply bio's at the start of our
messages).  I meant that in the paper conservation community, it's my
understanding that deacidification (ie. In this case, a final immersion
phase of treatment where the object is bathed in an alkaline solution
contributing hydroxides  and carbonates...), of papers as old as those
in question is not only unnecessary but may indeed be detrimental.  I
agree with you that there are no 'simple and easy treatments' which is
why we shouldn't get into the habit of deacidifying everything that
comes through the shop door.

Douglas Sanders
Conservator
Indiana Historical Society

> -----Original Message-----
> From: Jack C. Thompson [mailto:tcl@xxxxxxxxxxxx]
> Sent: Friday, January 24, 2003 4:03 AM
> To: BOOK_ARTS-L@xxxxxxxxxxxxxxxx
> Subject: Deacidification, etc.
>
> This is a complex question, requiring more than one answer.
>
> Deacidification is a fairly common adjunct to acqueous treatment
> of paper.  Buffering is not always part of such treatment.
>
> The measure of acid/base is a log scale measurement of ions, 7 pH
being
> neutral. (Don't ask me what this means; look it up and learn.)
>
> So.  Paper treated to make it pH neutral works best within the first
> seven years.
>
> Gelatine, a product of animal skin, etc. has a pH of approx. 5.5, and
> is very stable at that pH.
>
> Linen and hemp fibers have a pH of 6, or thereabouts.  Wood pulp paper
> has a pH somewhat higher (or lower), in general.  Depending on the
> chemistry used to reduce the fiber to a state suitable for the
manufacture
> of paper.
>
> There are no simple/easy treatments.
>
> Jack

             ***********************************************
            BOOK_ARTS-L: The listserv for all the book arts.
      For subscription information, the Archive, and other related
            resources and links go to the Book_Arts-L FAQ at:
                      <http://www.philobiblon.com>

        Archive maintained and suppported by Conservation OnLine
                    <http://palimpsest.stanford.edu>
             ***********************************************


[Subject index] [Index for current month] [Table of Contents] [Search]