Re: [BKARTS] animal hide glue

["Jack C. Thompson" <tcl@xxxxxxxxxxxx>]

Keep the 'rubbery' glue as an artifact.  Glycerin is added to hide glue
to make if flexible, but I doubt you'd find any conservator using it.

If the paper in the books you're working on is sound, you might use
a thin layer of gelatine with some wheat starch paste blended into it,
to make the adhesive layer more flexible (and easier to remove).

Only brush the adhesive on the paper, not the sewing cords/tapes, and
wipe any excess off.

The reason some old spines are brittle is because too much of a poor grade
of glue was used.

If you have access to a store which sells bulk food products, look for
food grade gelatine.  Put a little in your mouth and continue shopping.

As the gelatine swells and dissolves on your tongue it will either taste
neutral or slightly sweet; if it begins to taste sour, spit it out and
look somewhere else for gelatine.

A sour taste means that at some point during manufacture the gelatine
began to go moldy.  That doesn't necessarily make it bad, but it does
make it weaker than a batch which did not go moldy.

Glue is what is removed from hide or bone at a higher temperature than
was needed to remove gelatine.

If your examining a variety of grades of hide glue, the darker ones were
cooked out at higher temperatures, and are not as strong as lighter glues.

Jack


>We've been talking about paste, but I have questions about glue.  I want
>to know what is being used today...my books are 20years old.
>I am working on restoring 18th century books that had animal glue on the
>spines. I had to resew one book completely. What would you conservators
>use to glue up the spine again? I am tempted to use wheat paste so that it
>is completely reversible, but would it be better to use a hot animal glue?
>Are they really flexible enough? They seem very brittle to me when I get
>into an old book.
>What is used currently so that the restoration is really reversible?  I
>have some rubbery animal glue in a block. I don't know how old it is
>and I am afraid to use it...
>
>Thanks for your help,
>Carole Vanderhoof
>Lonely Pine Bindery
>

Thompson Conservation Lab.
7549 N. Fenwick
Portland, Oregon  97217
USA

503/735-3942  (ph/fax)

http://www.teleport.com/~tcl

"The lyfe so short; the craft so long to lerne."
Chaucer  _Parlement of Foules_ 1386

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