Now showing 1 - 3 of 3
  • Publication
    Understanding microcrystalline waxes for the seismic protection of art objects
    (American Institute for Conservation of Historic and Artistic Works (AIC), 2008) ;
    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.
      524
  • Publication
    Performance expectations for microcrystalline waxes for the seismic protection of art objects
    (Getty Publications, 2006-05) ;
    Use of microcrystalline waxes for the protection of ceramic art objects from seismic events is an inexpensive and relatively popular technique in museum exhibition practice (Fig. 1). Unfortunately, because of the high porosity of some ceramics and the fragility of their glazes and paints, the surface of many art objects may be vulnerable to damage from the microcrystalline wax application. Thus, a conservative approach is needed—applying only as much as is actually required to resist predicted levels of ground motion and transmitted forces caused by an earthquake movement. Determining the appropriate and most effective quantity of wax as well as verifying the best application technique (e.g., hot versus cold) is not clearly established by either industrial standards, museum conservation standards or product-oriented guidance. How much wax to use for specific sizes and weights of objects is left to a matter of empirical knowledge, judgment and a good deal of guess work. While sometimes reliable these approaches can lead to the ap-plication of a greater amount of wax being used than needed (resulting unnecessary risk to the object) or too little wax with respect to the object’s mass and the anticipated earth-quake threat (leading to an increase in the potential for). This ongoing study has begun to develop some performance expectations for microcrystalline waxes and suggests a number of application guidelines, based on chemical micro-structure and physical.
      1386
  • Publication
    Sample preparation and testing methods for the evaluation of microcrystalline waxes for the seismic protection of art objects
    Use of microcrystalline waxes for the protection of ceramic art objects from seismic events is an inexpensive and relatively popular technique. Unfortunately, because of the high porosity of some ceramics and the fragility of their glazes and paints, the surface of many art objects may be vulnerable to damage from the microcrystalline wax. Thus, a conservative application approach is needed – applying only as much as is actually required for predicted levels of ground movement. Determining this quantity and verifying the best application technique (e.g. hot versus cold) has yet to be established. This paper presents the development of testing techniques to optimize the application of microcrystalline waxes, specifically, the pioneering of tensile and shear sample preparation. These procedures were applied to 70 tensile and 175 shear tests on paraffin wax, beeswax, and 4 microcrystalline waxes. Static testing methods demonstrated the clear superiority of certain products and average performance capabilities of up to 167kN/m2 in tension and 89 kN/m2 in shear under light loading.
      2879