Stručni rad
Reconstruction of Bronze Vessel from Plećaševe Štale/Gornje Njive Locality
Borko Vješnica
Sažetak
Due to the conditions at the place where the finds had been excavated, in the ditch between two walls of the temple where water found its own way to flow along even though filled with layers of soil and rubble (containing archaeological remains), few fragments of metal finds stuck in the vacuum of clay in a layer of soil where they had minimum contact with air and therefore oxidized more slowly. I received bronze material which was compressed within a clod of hardened soil, like a kind of “sandwich”. Only a few-millimetre wide rim of the vessel (Fig. 1) is completely preserved reaching the side that continues into the shallow bottom; together they form round 60% of the preserved part of the bronze vessel. A precondition for easier conservation of the vessel remains would be separation of bronze sheet from the soil clod. In this respect I determined conservation and restoration phases:
- Removal of earth layers - I immerged soil clod with the parts of vessel into a small ultrasound tub filled with distilled water. A part of soil turned into mud and fell off, and the thin bronze sheet was now clean;
- Stabilisation of metal surface - I immerged separated parts of the sheet vessel into a wide fire-proof measure filled with distilled water saturated with sodium carbonate NaHCO3, and put them to simmer on a moderately warm ring. Afterwards, I boiled the complete material one more time in the distilled water, so that the remains of sodium carbonate were neutralised after the previous cooking;
- Flattening the dish rim- I warmed the bent edge of rim (softened the structure of the alloy at its critical point at high temperature) and folded it back to the bow direction of the rim line;
- Gluing dish fragments - having found the connecting surfaces of sheet parts, I glued them with both quick-drying adhesive and two-component epoxy resin; - Reconstruction and removal of calcite layers - in accordance with the material of the object to be reconstructed (thin bronze sheet) I decided to use thin sheet of brass alloy (Fig. 3), which could easily be folded into a wished shape, and was thinner than the original so that when the whole vessel was reinforced, a few layers of artificial patina/verdigris (Verdigris: a greenish blue substance that forms on the surface of some metals in wet conditions) could be applied. Having additionally reinforced the object, I could more safely remove the remains of calcite film o? the bottom of the shallow vessel;
- Fixing artificial verdigris and polishing - I used fine machine brushes to polish the original surface of the vessel in order to make green verdigris lustreless (Fig. 4); - Application of protective lacquer - the next step was to protect the whole surface of bronze vessel with Paraloid B72 protective lacquer in Ksilen C8H10 solvent; - Conclusion - all the above mentioned phases of conservation work on the bronze vessel aimed at the reconstruction of the vessel; they should be stressed because these vessel parts were in a very poor condition that they crumbled at a touch. I achieved two crucial things by the reconstruction: I reinforced the old weak material, and visually filled the empty surface of the metal vessel.
Ključne riječi
bronze vessel; conservation; reconstruction
Hrčak ID:
2898
URI
Datum izdavanja:
1.12.2005.
Posjeta: 2.406 *