Műtárgyvédelem, 2005 (Magyar Nemzeti Múzeum)

Összefoglalók

out, and many pieces had parted company with one another due to warping. The carving had suffered the most damage, with many pieces broken off or missing. There was evidence of infestation where weakened parts of the structure had crumbled, and in some places this was quite extensive.

Material analysis carried out enabled us to determine the make-up of the original layers of paint as applied to the wooden surfaces; these were as follows: a chalk ground containing protein binding media, a coat of paint also containing a binding agent based on protein, and an outer protective layer of protein, probably egg-white. On top of these were the following layers applied at a later date: a chalk ground containing oil binding media, and a coat of oil-based paint. When the pulpit was repainted the original gilding (which had been applied to both glutinous chalk ground and bole) was coated in a new layer of glutinous chalk ground and then re-gilded.

Restoration: the infestation was treated with methyl bromide gas (CH3Br). Peeling layers of original paint and gilding were bound with 4% gelatine solution. Then followed the two-stage removal of the non-original layers of paint: effected first with mechanical aids and then with Szuperkromofág solvent. This particular solvent was chosen because of its efficacy in removing layers of oil-based ground without damaging layers of protein-based ground underneath that it was the intention to preserve. There were certain parts where it was not possible to employ mechanical cleaning techniques. Here dabbing with solvent alone would have proved an extremely laborious process, so a cleaning gel containing methyl cellulose was utilized instead.

With the removal of the top repainted layers the original and very aged protective layer of protein once again became visible. Its condition, however, was such that it was felt to be aesthetically detrimental to the overall appearance of the object, and the decision was taken to remove it as well. Since this could not be carried out either mechanically or with water, a solvent had to be found whose properties were such that it would soften the layer of protein varnish and yet evaporate reasonably quickly and so not penetrate the original paint layer underneath. After completing various trials (see table) it was decided to use a mixture of Zoom solvent.

The non-original applications of gilding proved difficult to remove, with neither mechanical means nor repeated rinsing with water achieving any success. In the end a jet of hot air was carefully applied. This had the effect of softening up the top layer of gilding until it began to peel; it was then easily removed.

Throughout the restoration, wherever possible such materials and techniques were employed as would have been used in the pulpit’s original construction. Cracks in the wood were plugged with either pine or balsa, depending upon the load each part was required to bear. Lime was used for carving repairs and replacements. Those parts of the structure that had been significantly weakened as a result of infestation were reinforced with Paraloid B72 nitro-thinning solution. An isolating layer made up from Paraloid B72 5% nitro-thinning solution was applied to the surfaces of cleaned and repaired parts. Repairs to the primer were effected with 7% rabbit-skin glue solution mixed with chalk from Bologna and Champagne and small quantities of linseed oil, Dammar varnish and lavender oil.

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