STP1258

    Testing and Analysis of Terra Cotta Glaze Repairs

    Published: Jan 1996


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    Abstract

    Coatings and combinations were tested to establish a suitable repair for glaze loss on terra cotta whose substrate is otherwise sound. It was found that acrylic-based products deteriorated the least of those products tested, when subjected to accelerated weathering and freezethaw cycles. In addition, better results were achieved when the coatings were applied onto adjacent sides of the individual unit samples than when the coatings were applied flush with one side of the samples. Adhesion tests were performed on slick glazed surfaces and on surfaces that were roughened. Several coatings showed good adhesion to the glazed surfaces and adhesion was improved when the surfaces were roughened prior to the application of the coatings. Results indicate that coatings could be effective when applied over entire masonry units as well as when they are inpainted on the rough surfaces of a spall.

    Keywords:

    glazes, testing, spalls, coatings, freeze-thaw cycles, ultraviolet light, accelerated weathering, adhesion, water vapor transmission, coefficient of thermal expansion, preservation, rehabilitation, standards, building technology, buildings, evaluation


    Author Information:

    Viera, RJ
    Conservator, Building Conservation Associates, Inc., New York, NY


    Paper ID: STP15446S

    Committee/Subcommittee: E06.24

    DOI: 10.1520/STP15446S


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