GUIDELINES FOR THE CURATION OF GEOLOGICAL MATERIALS

(4) Adhesives. The adhesives, consolidants and supports used during preparation
should all be reversible, both in the short term and, since their later removal
may be necessary, also in the long term. Many commonly used natural and
synthetic resins become unstable or are liable to become intractable after even a
few years exposure to the atmosphere. In particular the use of shellac, animal
glues, cellulose nitrate, epoxy resins, and polyesters, and products containing
them, should be avoided. Cyano-acrylates ('Superglue'), although in common
use, require careful application, and their aging characteristics are poorly known.
It is always advisable to consult the manufacturer or supplier about the durability
of their products before using them on irreplaceable specimens. The use of new
materials should always be checked by reference to current conservation
literature (e.g. Art and Archaeology Technical Abstracts of the International
Institute of Conservation, published by the Conservation Center of the Institute
of Fine Arts, New York University. See Appendix 1 for notes on various
adhesives.
(5) Specimen .support. Specimens undergoing mechanical preparation are exposed
to percussive shock and vibration during development and therefore time
and effort should be expended in providing adequate support and protectiof~.
Temporary supporting media (e.g. water-soluble wax, therrno-plastics with a low
temperature melting point, sand bagging and embedding techniques, etc.) can be
used but the selection of the most appropriate is dependent upon the characteristics
of the specimen and this must rely upon the judgement of an experienced
preparator.
(6) Conclusion. Even the most basic preparation, chemical or mechanical,
requires both specialist knowledge and considerably time if it is to be carried out
effectively. Of paramount importance during preparation is the maintenance of
records of the processes and materials involved; these together with drawings,
photographs and notes or observations should be properly filed and not stored
with the specimen concerned. (See B5.3.3). While in the laboratory, specimens
not being actively worked upon should be kept in a location that is both secure
and meets the environmental requirements of the material or returned to the
main collection, store or exhibition.
2.2.1.2. Repair and consolidation
The consolidation and repair of fossil specimens requires adequate facilities for
storing, handling and applying a variety of resins and solvents and, in specialised
laboratories dealing with fossil vertebrates, access to vacuum impregnation
equipment, large sand trays etc.
Repairs to badly damaged specimens often require considerable experience and
patience and this type of work does not suit all individuals. With simple repairs to
fresh breaks it is often necessary to prime both sides of the break by
consolidation, using a hardener which is compatible with the adhesive to be
applied. When repairing fractured old breaks it is important to ensure that all old
glues, waves, etc. are removed from the joint areas as these may impede the
setting of modern adhesives. When setting up complex repairs use should be
made of a sand tray, sand bags and such supporting rigs as are necessary, for
example, laboratory scaffolding. Fractures in large of heavy specimens may need
dowelling, this however usually necessitates destruction of some of the original
specimen and should be avoided wherever possible. Consideration could be given