Treasures from the conservators’ workshop
How archaeological finds are reborn
Only a few people are familiar with the conservators’ workshop, where finds get cleaned of impurities, old, faded colours are revitalized and broken pieces become whole again.
Similar to other museums, the conservators’ workshop of the Archaeological Heritage Protection Directorate of the Hungarian National Museum, which is responsible for archaeological duties related to large investments, is full of curiosities. The majority of the excavation finds are pottery sherds, which are spread out and organized on large tables. Currently Celtic tools and jewellery, as well as coins from the Middle Ages are queued up to have external damages reverted and missing parts restored in order to halt the process of deterioration. Several tools and machines are used for restoration work, including microscopes, ultrasound depurators, abrasive blasting equipment, extractor hood, micromotor hand sanding tools, infrared lights, medical scalpels, eye spears, tongs, and so the list continues. Various chemicals are also used for artefact protection.
Conservation is a complex and meticulous process which requires the cooperation of a wide range of experts, such as conservators, archaeologists, anthropologists, geodesians, illustrators, photographers and geologists. It is a group effort where everyone contributes so that, after thorough conservation work, the full picture can be pieced together. The conservation of the following ceramic, antler, bone and metal finds, which are brought in from the excavation site covered in dirt, limescale and corrosion, showcase the transformative nature of the overall process.
When restoring ceramics, cleaning has to be done carefully. It is always important to confirm if the find can be cleaned with water; in the case of painted, encrusted or poorly fired vessels, the use of water should be avoided in favour of dry-cleaning methods. In the case of vessels which were brought in ‘in situ’ (embedded in or filled with soil), the soil is always stored separately for later analysis.
The conservation of bone objects also requires a lot of care and attention, since in addition to dirt, limescale is also often present. This makes the conservation of the find difficult, as limescale can often be harder than the bone itself, meaning that careless mechanical cleaning can easily damage the bone surface. The use of chemicals or moistening requires great caution, as rapid drying can cause the bone to warp, crack, or in extreme cases, completely deteriorate. It is best to use dry-cleaning methods under the microscope in the case of tougher stains or depositions, with the aid of an ultrasound depurator.
The surface of metal finds is usually covered by corrosion, dirt and carbonate depositions, which can be removed either mechanically (with the use of micromotor hand sanding tools fitted with the right abrasive head or ultrasound depurators) or with the use of chemicals. Chemical bath deposition is particularly useful when cleaning finely crafted finds made of precious metals, as it removes corrosion layers and keeps the risk of damaging the find to a minimum. The use of chlorine is generally avoided in the case of iron objects, instead, a natrium-hydroxide bath is used, followed by thorough washing and rinsing, neutralization, drying and passivation with the use of 10% tannic acid. At the end of the conservation process, a waterproof coating is applied to the surface in order to protect the find from potentially harmful atmospheric humidity.
Zsuzsanna Anita Pálfalvi
Vessel with pedestal, Neolithic Period, late 6000 BC
Vessel with incised decorations, Neolithic Period, late 6000 BC
Axe socket made of an antler with incised decorations, Late 6000 BC
Pedestal bowl, Neolithic Period, late 6000 BC
Iron knife, La Tène Period, 3rd century BC
Germanic bone comb, 4-5th century AD
Bridle, Hungarian Conquest Period, 10th century AD
Silver coins, Árpádian Period, 12th century AD
Gilded silver ring, Early Modern Period, 17-18th century AD
Gilded silver needle, Early Modern Period, 17-18th century AD
Archaeologist’s Diary
The rebirth of an Iron Age vessel
Few people realise that archaeological excavation is not the last chapter of the life of a find, but the beginning of a new era. And restoration, behind the scenes, is an almost indispensable part of this process, with the main aim of conserving the artefacts, prolonging their life, restoring them to a form close to their original state and preserving their aesthetic value.
This complex role is illustrated by the restoration of a pot from a Late Iron Age burial site Novajidrány-Sárvár erdészház, which once served as a grave good. The artefact was excavated by the archaeologists, together with the soil that had been filled in after the burial. Before being dismantled piece by piece in the conservators’ workshop, the pot was x-rayed and the interior was found to contain three metal objects. Being Late Iron Age pottery, the material of the pot was very delicate and easily disintegrated, which meant that it could only be handled with great care. The dismantling was carried out step by step, with a photo recording of the process. This revealed the three metal objects previously visible on the X-ray image: an iron brooch (fibula) and two bronze bracelets.
Once the assemblage was unpacked, each sherd was cleaned and the fragments were put together to restore the vessel’s original shape. Missing parts were filled in with plaster to make the artefact more stable and present a more uniform overall appearance.
(Excavation lead: Emese Zsiga-Csoltkó. The restoration process was coordinated by the author, the X-ray images were made by Mátyás Horváth, the dismantled metal objects were conserved by Imre Balogh, while the vessel was completed by Ágnes Nagy.)
Zsuzsanna Anita Pálfalvi
Ornate hairpins from Szécsény
During the 2019 excavation of the site Szécsény–Kossuth Lajos út 4. (Borsod-Abaúj-Zemplén county), two Early Modern Period gilded silver hairpins with garnet inlay came to light from one of the excavated burials. Both pins were affected by heavy copper corrosion, which, based on mechanical cleaning carried out under microscope in the conservators’ workshop, was due to the high copper content of the silver ore that was later gilded. Corrosion layers can be removed via several methods, either mechanical or chemical. In the case of the hairpins, chemical cleaning was chosen, because of the relatively intact status of the gilding on the silver surface. Bathing the finds in a complexing agent removed the corrosion layer without damaging the pins or the garnet inlay during the process. Loosened impurities were removed with a soft bristle toothbrush while being immersed in distilled water. In order to protect the pins from atmospheric moisture, the cleaned and dried finds were given a waterproofing coat consisting of 3% acetonic Incralac.
Imre Balogh
RÓLUNK
A MuseuMap aggregációs szolgáltatásának kiterjesztése, ahol a műtárgyak történeteivel, virtuális kiállításokkal és térbeli tárgyrekonstrukciókkal a magyar kultúra kincsei elevenednek meg.
KAPCSOLAT
MNM OMMIK
1088 Budapest, Múzeum krt. 14-16.
ommik@mnm.hu
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