Zprávy památkové péče 2016, 76(4):424-432

Plague column in Kutná Hora - comprehensive preparation for restoration work

Jakub Ďoubal, Roman Kolář

The Plague column in Kutná Hora was constructed in 1713-1714 by the Jesuit coadjutor František Baugut. During its existence, it has undergone a number of modifications and corrective interventions that have brought quite a few problems to the present time. A restoration survey pointed out the complex issue of degradation of the surface layers of the biodetritic limestone, associated with the closure of the gypsum surface crusts and previous restorations that utilized a wide variety of materials ranging from cement through epoxy resin to acrylic dispersion. The survey also confirmed the assumption that the column was repeatedly treated with surface finishes in the past, revealing a number of fragments from these finishes.
In 2013, the Faculty of Restoration of the University of Pardubice carried out a detailed restoration survey focused on the composition of deposits enclosing the surface of the stone and on the possibilities of creating images of the crusts and other debris. Exemplary restoration was subsequently performed on selected portions, which tested the potential of the individual restoration operations. For crust imaging, chemical cleaning using carbonate and ammonium bicarbonate, microabrasion imaging with different abrasives, and cleaning using a Q-switched Nd: YAG laser were tested. From the tested methods, the method using the laser was confirmed as the most appropriate, as confirmed by both macroscopic examination and laboratory tests.
As part of the restoration of the sample area, the time demands and the feasibility of using laser cleaning on the examined object were also verified. The execution of a model field significantly helped to refine the proposed technologies and to verify their use. Taking a sample as a basis for the restoration of larger objects allowed for a relatively accurate determination of the estimated cost of the restoration and also allowed for a specification of the proposed technologies and assessment of the aesthetic impact of the restoration as relevant. Finally, the restored part of the model may serve as a reference surface for subsequent quality control of the work performed.

Keywords: Kutná Hora; Plague Column; restoration; laser cleaning

Published: December 1, 2016  Show citation