Page 184 - The Building Conservation Directory 2013
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t h e b u i l d i n g c o n s e r vat i o n d i r e c t o r y 2 0 1 3
T w e n t i e t h a N N i v e r s a r y E D I T I O N
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INTERIORS
SCAGLIOLA
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HAYLES AND HOWE LTD ORNAMENTAL PLASTERERS
Templegate, Mead Rise, Bristol BS3 4RP
Tel 0117 972 7200 Fax 0117 971 2232
Email
PAPIER MÂCHÉ
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FARTHING & GANNON
Filey Cottage, Mounts Lane, Newnham,
Northamptonshire NN11 3ES
Tel/Fax 01327 310146
Email
CONSERVATION AND RESTORATION OF SCAGLIOLA, HISTORIC
PLASTERWORK AND APPLIED ORNAMENT
: See also: profile entry in
Plasterwork, page 186.
When the most suitable cleaning and restoration methods have
been chosen and the paint removed, the surface can be inspected again
for further defects. At this stage any hidden filling will come to light.
Dirt on the original surface can now be carefully removed.
If the decision has been made to cut back the surface of the
scagliola and restore it, the next step is to start cutting back the surface
with a coarse abrasive paper, gradually moving to fine. As the work
proceeds, all loose and friable material is removed, and damaged areas
are repaired with fresh scagliola mix to match. These repairs must
be done wet to reduce suction and to enable adhesion. Once set, the
process of cutting back restarts, gradually moving to the finer grit and
even finer powders if required, retracing the final finishing process
of the original manufacture as far as can be determined. This cycle
is repeated as many times as necessary until a sheen starts to appear,
before carefully and delicately applying the specified finish.
Matching the highly polished surface of scagliola requires careful
selection of abrasives with the appropriate particle size for each stage
of the procedure, as well as a suitable polish. The abrasives range from
very rough plaster planes of 80 grit through to 1600 grit, finishing
with fine powders. French polish, linseed oil, milk and a number of
modern waxes have all been used to achieve a high gloss. Sadly, modern
urethane coatings have also been widely used in the past, and these may
need chemical removal.
The stunning lapis lazuli scagliola columns in the Music Room at
Buckingham Palace posed a very interesting problem. The columns
which were originally made in 1836 by William Croggon and his team
included a mix of filings of brass, tin and copper, to give a gold and
silver flecked appearance to the blue sheen. The filings immediately
began to corrode and expand, blowing pits in the surface. This process
continued slowly for 150 years, but when the Palace State Rooms were
recently opened to the public, the decay began to accelerate as a result
of the additional moisture generated by visitors. To restore the columns
to Nash’s original design it was decided that a treatment using beeswax
mixed with some rare, specially selected pigment and finished with a
lighter grade of wax to give a shine would protect the columns without
obscuring them from view.
Recommended Reading
A Zecchini, Arte Della Scagliola sul Lario, Editore U Hoepli, 1997
Geoffrey Beard, Craftsmen and Interior Decoration in England 1660–1820,
Bloomsbury Books, London 1986
WilliamMillar, Plastering Plain and Decorative, 1st Edition 1897,
facsimile edition, 1998 Donhead, Shaftesbury
GilesWorsley, ‘BuckinghamPalace, London’ – Country Life 5th August 1993
David Harrison
is managing director of Hayles and Howe Ltd in
the UK and Hayles and Howe Inc in the US (see page 187). Working in
traditional fibrous plaster as well as specialist scagliola enables the
two companies to provide a wide range of design specifications and
finished products. A book by his colleague David Hayles, The Magic of
Scagliola, is currently being prepared for publication.
Marezzo marble columns at Stamford Old Town Hall, Connecticut: over-painting
has been stripped and the underlying surfaces are being cleaned and repaired
prior to polishing.
