Understanding microcrystalline waxes for the seismic protection of art objects

Abstract

Use of microcrystalline waxes for the protection of ceramic art objects from seismic events is an inexpensive and relatively popular technique. This paper presents performance results for three commercial, microcrystalline waxes based on anchoring requirements of resisting seismic-induced tensile and shear forces, while exhibiting a ductile failure mode to prevent objects from suddenly detaching themselves from their display units and becoming sufficiently mobile to fall off stands or collide with other art objects. As many of the testing techniques described in this paper are not easily accessible to the average museum conservator, and some of the products may not be readily available, emphasis is placed on establishing an expected range of strengths, and correlations are suggested for predicting the general performance of any microcrystalline wax in a specific application arrangement, based on easily performed, simplified tests that were found to be able to predict tensile capacity within 10%. Distinctive performance trends were found amongst various products with capacity being as much as 183 kPa in tension and 42kPas in shear. The pre-application of a methylacrylate copolymer to the bonding surface consistently improved performance, while increasing wax thickness did not.