Cleaning wood sections

Sally Shelton <libsdnhm [at] class__org> writes

>We have a section of a redwood tree that has been on exhibit A Long
>Time. The surface coating is very thick and deteriorated. I  suspect
>that it started out as an annual application of shellac and then got
>into fully synthetic polymers.

A similar problem was encountered here with coatings, thought to be
shellac, on the surfaces of Lower Jurassic fossil marine reptiles. A
solvent gel mixed as follows: isopropyl alcohol 400 ml, toluene 50
ml, Ethomeen C/25 20 ml, Carbopol 954 6g, water (deionised) 50 ml,
was used to good effect. The details of application and safe use are
described in Cornish, L. et al. 1995. The Gallery 30 Project:
Conservation of a collection of fossil marine reptiles. The
Conservator, 19: 20 - 28.

William Lindsay
Head of the Palaeontology Laboratory
Natural History Museum
Cromwell Road
London, SW7 5BD
+44 171 938 8821

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                  Conservation DistList Instance 9:73
                    Distributed: Sunday, May 5, 1996
                        Message Id: cdl-9-73-003
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