Home Conservation projects Conservation And Restoration Of Small Leather, Wood And Rope Artefacts From The Flaciusova Ulica Archaeological Site In Pula

Conservation And Restoration Of Small Leather, Wood And Rope Artefacts From The Flaciusova Ulica Archaeological Site In Pula

From July to December of 2014 the restoration workshop of the International Centre for Underwater Archaeology in Zadar conducted conservation and restoration work on leather artefacts, sections of rope and very small wooden artefacts found with the remains of two Roman wooden boats discovered during archaeological investigation at Flaciusova ulica (Flacius Street) in Pula. The archaeological investigation was conducted in 2013 under the leadership of the Archaeological Museum of Istria in Pula. The conservation and restoration work covered 86 wooden and 14 leather artefacts and seven sections of rope. Of particular interest among the finds received for treatment were items of small wooden ware, small boxes, lids, baskets, various wooden tools, writing tools, leather soles and the like. The artefacts were received in the workshop following the desalinisation process.

Upon receipt the finds were documented photographically and with detailed descriptions. Following a detailed visual inspection the course of conservation and restoration procedures and the selection of substances and materials to be used in the treatment were determined. The cleaning of deposits of dirt from the surfaces of the artefacts was conducted in controlled conditions, under magnification and under a light flow of water, using soft brushes and fine laboratory tools.

 

 

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Cleaning the leather soles with fine laboratory tools


The leather and rope section finds were isolated in polyethylene nets and placed in distilled water. The cleaning process was followed by the consolidation procedure, i.e. the impregnation of the artefacts. Consolidation of the archaeological rope was effected by the method of submersion in a 10 to 15% solution of glycerine in distilled water, while leather was submersed in a 30% solution, also of glycerine in distilled water. Consolidation was conducted by immersing the artefacts in the glycerine solution for a period of two weeks. The consolidation of the leather artefacts was followed by the dehydration procedure using acetone. The finds were then subjected to controlled drying in atmospheric conditions for a period of several days. The leather was dried under pressure to ensure that the artefacts retain their original form.

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The leather soles of Roman sandals with preserved iron clasps following the conservation and restoration work


Unlike leather, the process of dehydrating and consolidating the wooden artefacts runs in the opposite sequence. The wood is first entirely dehydrated, with impregnation following only upon completion of the process. Dehydration was achieved by immersing the finds in three successive four-day acetone baths. This procedure ensured the complete removal of water from the structure of the artefacts.

The process of consolidation, i.e. impregnation, involved the use of natural pine resin (colophony). The artefacts were immersing in a 67% solution of colophony in acetone in closed containers at a temperature of 52ºC. This process lasted four weeks and was followed by the gradual and controlled drying of the wooden finds by exposure to atmospheric conditions for several hours per day. The process was monitored by the weighing of the mass of each individual find prior to and following exposure to atmospheric conditions. When a constant mass was achieved the process of the drying of a given wooden artefact was completed.

Wooden artefacts that were received in multiple fragments were affixed with cyanoacrylate glue.

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Affixing the fragments with cyanoacrylate glue


The joints of these artefacts were reinforced by integration using Araldit SV 427 two-component epoxy resin for wood. A complete reconstruction was effected of some finds, such as wooden boxes and lids, using the same two-component epoxy resin. A mixture of Cosmoloid H80 and Paraloid B72 in acetone was applied to the surface of all wooden artefacts as a final protection. The integrated sections were toned using acrylic paint in a colour similar to the original colour, but a shade lighter such that the integrated surface can be differentiated while still forming a meaningful whole.

 

A Roman wooden box before conservation-restoration treatment

A Roman wooden box after conservation-restoration treatment

 

In order for the conserved and restored material to remain protected and secure, adequate conditions and storage must be ensured and the finds handled carefully to prevent chemical and microclimatic impacts.

A Roman wooden basket before conservation-restoration treatment

A Roman wooden basket after conservation-restoration treatment


Marina Šimičić