HPCS U.S. Projects, Gould Memorial Library

AD 25 Gel's thixotropic properties are ideal for repairing cracks in plaster ornament

Bronx, New York (1899)



The Building: 

National Historic Site designed by Stanford White.


The Issue of Concern:

There was serious concern for public safety after a cast plaster ornament (rosette) fell off the ceiling of the Guastovino tiled dome. In addition, the large cast plaster figures were severely damaged by vandalism during student demonstrations. 
Project Synopsis:

Historic Plaster Conservation Services was retained to conserve the large cast plaster figures and hundreds of rosettes that populate the dome. A borescope was used to investigate the interior of the cast plaster figures, revealing numerous cracks.

Large cast plaster figures populate Gould Memorial Library
 Large cast plaster figure re-secured
HPCS devised a remote guided product delivery tool equipped with a syringe to inject HPCS AD 25 Gel™, an injectable dowel setting adhesive with thixotropic properties, into the cracks. This was done with minimal impact on the exterior of the figures. The rosettes were “dry” cleaned with soot sponges and re-secured with AD 25 GelTM. Pins were installed to give each rosette a mechanical connection.  

To review the project report, see the Gould Memorial Library Report in the Document Library.











CO F-50 Primer™ AD 25 Gel™  
CO F-50 Primer™ AD 25 Gel™
Boroscope and remote guided product delivery tool.