Saving Faces

British Museum

Conservation of a plaster cast of a Maya monument from Quiriguá

The British Museum holds more than 400 plaster casts from Ancient Maya sites in its collection storage. These form part of the collection of Alfred Maudslay, who travelled through Central America and Mexico in the 1880s and explored many ancient Maya sites, taking photographs and having moulds made of the monuments.

The white tissue, pictured left, is a fine fibreglass that was used to repair and support the break edges along the back of the cast.

Jars of acetone and Paraloid B72 adhesive and glass microballoon paste used to repair the cast.

Ratchet Straps and clamps were used to hold the fragments in place whilst the object was repaired.

Conservation tools used to repair the cast including: soft brushes, bamboo skewers, dental tools, metal spatulas, fine tweezers, insulin injection needles and micropipettes.

Maudslay photograph of Quiriguá Zoomorph B East side Glyphs 0-3.

Quiriguá Zoomorph B East side Glyphs 0-3.The original Maya monument is carved from a red sandstone. The cast was once painted for display but the colour has only a vague resemblance to the original monument.

Before conservation; zoom in to the top right corner to see the cracks which are visible upon close inspection.

The back of the object shows the extent of the cracks and loss of plaster along the central metal dowel.
The cast has 3 metal supports running vertically through the cast, one on each end and one in the centre. The metal gives strength to the overall structure of the cast but at the same time there is an area of vulnerability at the interface between the metal and the plaster. The materials have different flexibility and rate of expansion and contraction and this is where a crack has appeared along the centre metal support of the cast. There is also a horizontal crack which is in-between the top and bottom registers of the glyphs, essentially breaking the object into four pieces.

Conservation student Sayuri Morio tightening ratchet straps. The British Museum's Conservation Department regularly hosts students on placement. Sayuri Morio is an undergraduate from City and Guilds London Art School. Working on the Maudslay casts has given Sayuri the opportunity to gain valuable hands-on conservation skills.

The task to conserve this cast was to re-align the four fragments which had sprung under tension. These fragments were re-aligned using three ratchet straps and two clamps shown here. A ‘dry run’ to align the fragments into the correct position took two conservators over 2.5 hours.

The cast with clamps and ratchet straps;
they remained in place over a few days to allow the adhesive to set. Notice the blue glove on the clamp, an easy way to highlight to other members of staff to be aware of the protruding clamp.

The missing plaster is gap-filled using an adhesive mixed with glass microballoons, followed by several layers of fibreglass tissue impregnated with an adhesive, similar to applying paper mache.

Sayuri Morio using a cotton swab and solvent to shape the microballoon fills.

Tub of Paraloid B72 and Glass microballoons used as a gap-fill for the areas of missing plaster on the back as well as on the front of the cast. Microballoon paste is mixed to the consistency of a thick icing and is often applied with a metal spatula.

Conservator Amy Drago in-painted gap-fills using a fine brush and acrylic paint.

Acrylic paints are often used in conservation because they are reversible and can be removed in the future if necessary.

Detail of cast with white microballoon fills (bottom left corner) before the fills are in-painted to match the surrounding plaster.

During retouching using fine brushes and acrylic paint.

Detail of completed retouching.

The conservation treatment complete.

Credits: Story

All images © Trustees of the British Museum
Text and image selection: Amy Drago
Special acknowledgment to Sayuri Morio for her work and photos
Thanks to: Claudia Zehrt, Kate Jarvis, Jonathan Mortemore, Christos Gerontinis, and other BM Google Maya Project collaborators

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
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