Acrylic adhesives

Sarah Reidell <reidellsarah [at] yahoo__com> writes

>Priscilla Anderson <priscilla_anderson [at] harvard__edu> writes
>
>>We are experimenting with Lascaux acrylic adhesives (498 HV in
>>particular) for use in book conservation, and want to know how
>>conservators in any fields use (or don't use) this class of
>>adhesives.
>
>At the Conservation Center for Art and Historic Artifacts (CCAHA),
>we use Lascaux 498HV on select leather repairs. In particular,
>technicians have been using the Lascaux 498HV for use in repairing
>the deteriorated leathers on a collection of 100+ biological
>specimen boxes by Titian Peale, following the Harvard method of
>solvent-reactivated Lascaux-coated Japanese papers. The boxes,
>dating from the mid-nineteenth century, look like books bound in
>half leather and marbled paper with a glazed specimen box
>"textblock" that opens from both the front board and the back board.

I started using 498 HV coated supports long ago and in similar ways
and for similar purposes as those evoked for books by Sarah Reidell,
but also as local interface reinforcement for heavy tears in canvas
paintings before or instead of relining, as local consolidation and
mending, etc. It is thermoplastic and solvent soluble acrylic paste
which Lascaux produced in gelling the dissolved resin with toluene.

As support for this paste I used mainly non-woven polyester fabric
from Lascaux, called Lascaux-Vliess (fleece), available in two
weights, 10 and 20 grams per square meter. 10 gr/sqm is by far
strong enough. To coat it I put a piece of the fleece on a glass
plate and apply 498HV with a rubber spatula, leaving as little as
possible of the resin paste on the fleece. The coated fleece is then
pulled off the glass plate and dried like laundry, free-hanging on
the line. Dry, it's stuck away interleaved until one needs it.

To apply the now dry, coated fleece (there is nearly no mass to it)
it is cut to size with a pair of scissors, then held with tweezers
into a little container filled with toluene (all action taken in an
aspirated booth), left in the solvent  for just a few seconds,  long
enough to get the coating back into glossy gel state (no drippings)
and then applied. I usually press it lightly with a small brush,
slightly soaked with toluene, to the surface it needs to adhere to
and have it dry there for a few minutes without applying further
pressure. I won't explain all the trials made beforehand, where to
use it and where not. The gloss is gone again--because of loss of
solvent--I then put on pressure as needed, mostly with small
sandbags. I have thus coated pieces of fleece, which are more then
20 years old! They have no discoloration nor has hardening occurred;
reactivation takes as little time as then--the system still
functions perfectly well. I haven't produced coated fleece for a
while, so I don't know if 489HV is now laid out to allow for
reactivation with acetone, which would be more convenient.

Hans-Christoph von Imhoff
31, Blvd. de Pirolles
1700 Fribourg / Switzerland
+41 26 321 14 44
Fax: +41 26 321 14 40


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                  Conservation DistList Instance 16:76
                   Distributed: Friday, May 30, 2003
                       Message Id: cdl-16-76-002
                                  ***