Weatherproof varnish for oil paintings

Pippa Balch <pippa.balch [at] maritimedata__com> writes

>I am a painting conservator working in a London studio.  We have
>been asked to treat a small series of decorative oil paintings
>(transferred from oak panel to silk and plywood) which will be
>outside, unprotected, on two separate occasions later in the year.
>We would be interested in any ideas on the best varnish system to
>use, to offer protection in case of rain.  The surface coating
>needn't be a long-term solution, since the paintings will not be
>exposed in this way in the future, but must at least be reversible
>after 3-4 months.  We are considering Paraloid B72, perhaps with an
>additional waxy coating.

In 1987, the museum purchased a 1920's Hershell-Spillman carousel
for visitors to ride on. The rounding boards were decorated with
scenes painted in oil paint on galvanized iron sheet. The iron was
beginning to rust on both the front and back, where there were small
holes or scratches through the paint. Although a tent forms a roof
for the carousel that covers the carousel mechanism and horses, the
rounding boards are on the outside of the tent cover and are,
therefore, exposed to sun and rain for 6 months. They are stored in
an unheated barn for the winter months.

We have applied a coat of Liquitex Soluvar Final Picture Varnish
(50% Gloss / 50% Matte) each year. No attempt has been made to
remove the old Soluvar before re-application because it appears to
have been "worn" away after 6 months exposure. Although I am sure
there is still some film left, we simply apply a new coat each year.
Judging from the appearance of the rust spots that were visible when
we bought the carousel, this coating seems to be working quite well.
The rust spots have not grown noticeably over a 14 year period, and
we do check the appearance of each scene against a record photo each
year.

Richard L. Kerschner
Director of Preservation and Conservation
Shelburne Museum
PO Box 10, Route 7
Shelburne, VT  05482
802-985-3348 ext: 3361



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                  Conservation DistList Instance 15:57
                 Distributed: Friday, February 15, 2002
                       Message Id: cdl-15-57-005
                                  ***