Conservation Of Waterlogged Wood Research Articles

Multimedia Photogrammetry for Automated 3D Monitoring in Archaeological Waterlogged Wood Conservation

Abstract. This study addresses the challenges inherent in preserving archaeological waterlogged wood, which is prone to deformation and decay if not stabilized immediately after recovery. Conventional preservation methods, such as impregnation with polyethylene glycol (PEG) solutions, often result in undesirable dimensional changes. To obtain exact spatio-temporal information on the deformations during the conservation process, a photogrammetric monitoring system, utilizing a stereo camera facing from air into the liquid, attached to an automated biaxial measurement unit is proposed. Special target heads were developed and attached to the wood to provide deformation points. Refraction correction was applied to the imaging model by ray tracing, and indirect flat lighting was used to mitigate turbidity. The system observed logs from a wooden track from the first century, subject to conservation. Subject of investigation were the influence of refraction negligence and scale definition in a bundle geometry, similar to bathymetric aerial setups. Results show that refraction correction is imperative for good results. Furthermore, scale definition with highly accurately determined scale bars and inclusion of relative orientation constraints provide further accuracy improvements.

Archeological wood conservation with selected organosilicon compounds studied by XFM and nanoindentation

Waterlogged wood conservation is a complex and challenging task. Detailed knowledge about the interactions between the applied chemicals and wood is necessary to ensure the effective and safe conservation of wooden artifacts. The present research aims to determine the mechanism of dimensional stabilization of archeological wood by organosilicon compounds using the combination of synchrotron-based X-ray fluorescence microscopy (XFM) and nanoindentation. Archeological oak wood was treated with methyltrimethoxysilane, (3-mercaptopropyl)trimethoxysilane, or 1,3-bis-[(diethylamino)-3-(propoxy)propan-2-ol]-1,1,3,3-tetramethyldisiloxane, which in previous studies were found to be more effective than other organosilicons in stabilizing wood dimensions. The XFM and nanoindentation results showed that all three organosilicons infiltrated wood cell walls and enhanced their mechanical properties. The XFM also showed that part of the chemicals filled some void spaces like cell lumina. Based on the results obtained here and in our previous research, it is determined that the mechanism of archeological wood dimensional stabilization by organosilicon treatment is complex and likely involves both filling cell lumina and infiltration into cell walls where organosilicons interact with wood polymers.

Conservation of Waterlogged Wood of the Yenikapı Shipwrecks, Istanbul-Türkiye

Theodosian Harbour was one of the principal harbors of Byzantine Constantinople, actively serving trading ships from the 4th to the early 11th centuries AD at the Sea of Marmara shore of the imperial center. Almost ten years of rescue excavations by Istanbul Archaeology Museums in the silted harbor site revealed considerable archaeological evidence dating from the Ottoman and Byzantine periods to the Neolithic age. The artifacts uncovered within the Byzantine harbor context constitute the majority of archaeological finds yielding much information on the trading network of the imperial center. Upon the invitation of the Istanbul Archaeological Museums, Istanbul University undertook the removal, documentation, and construction technology studies of twenty-seven shipwrecks and the conservation work of 31 shipwrecks. For conserving the waterlogged timbers, mainly PEG (polyethylene glycol), preimpregnation+vacume freeze drying, or melamine-formaldehyde (Kauramin®) resin for the highly-degraded timbers is used. The present paper discusses the conservation processes of the shipwrecks excavated under the responsibility of the Istanbul University’s Department of Conservation of Marine Archaeological Objects.

Reactivity of Microcrystalline Cellulose with Methyltrimethoxysilane and 3-(2-Aminoethylamino)propyltrimethoxysilane.

In the presented research, two trialkoxysilanes were used to investigate their reactivity with microcrystalline cellulose (MCC) applied as a model material. As a continuation of the previous study, the research aimed at evaluation of the durability and potential reversibility of the silane treatment. Two different solvents and a mixture thereof were used for cellulose modification. The influence of amino group/pH, an excess of silanes and re-soaking with water on binding with cellulose was examined. The results obtained confirm that both selected silanes can effectively modify MCC. However, the treatment with 3-(2-aminoethylamino)propyltrimethoxysilane occurred more effective than with Methyltrimethoxysilane due to the presence of amino groups. Among the three tested solvents, the most effective was pure water. In contrast, the use of ethanol and a mixture of ethanol and water gave significantly worse results. Summarising, the presented research clearly shows how important the type of the functional group in alkoxysilanes is for its chemical reactivity with natural polymers, which is crucial for their application in waterlogged wood conservation.

Conservation of Waterlogged Wood—Past, Present and Future Perspectives

This paper reviews the degradation, preservation and conservation of waterlogged archaeological wood. Degradation due to bacteria in anoxic and soft-rot fungi and bacteria in oxic waterlogged conditions is discussed with consideration of the effect on the chemical composition of wood, as well as the deposition of sulphur and iron within the structure. The effects on physical properties are also considered. The paper then discusses the role of consolidants in preserving waterlogged archaeological wood after it is excavated as well as issues to be considered when reburial is used as a means of preservation. The use of alum and polyethylene glycol (PEG) as consolidants is presented along with various case studies with particular emphasis on marine artefacts. The properties of consolidated wood are examined, especially with respect to the degradation of the wood post-conservation. Different consolidants are reviewed along with their use and properties. The merits and risks of reburial and in situ preservation are considered as an alternative to conservation.

Organosilicons of different molecular size and chemical structure as consolidants for waterlogged archaeological wood \u2013 a new reversible and retreatable method

Ineffectiveness of the chemicals applied so far for waterlogged wood conservation created the need to develop new more, efficient and reliable agents. As an alternative, a new method with the use of organosilicon compounds differing in chemical composition and molecular weight has been investigated. The results obtained show the potential of organosilicons as consolidants in waterlogged wood conservation able to effectively stabilise wood dimensions upon drying. The best wood stabilisers were low-molecular organosilicons enable to penetrate the cell wall as well as chemicals with functional groups capable of interacting with wood polymers and forming stabilising coatings on the cell wall surface. The best anti-shrink efficiency values were obtained for (3-Mercaptopropyl)trimethoxysilane, (3-Aminopropyl)triethoxysilane, 1,3-Bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, reaching 98, 91 and 91%, respectively. Most of the applied organosilicons reduced wood hygroscopicity, which limits the risk of further dimensional changes of wood exposed to a variable air moisture content and potentially reduces wood biodegradation. In the light of our studies, the proposed method of waterlogged wood conservation with organosilicons is potentially reversible in the case of siloxanes and amino-silanes as well as retreatable, which complies with the requirements of the conservation ethics.

An attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic study of waterlogged woods treated with melamine formaldehyde

Various different methods are used for the conservation of waterlogged wood. One of them is melamine formaldehyde method which is also used for the conservation of highly degraded woods of the Yenikapı shipwrecks. In this method, melamine formaldehyde resin is replaced with the water inside the waterlogged wood. After the impregnation and the drying process, the acquire dimensional stability. In order to sustain a successful conservation procedure, the wood should be impregnated with the resin. Otherwise, shrinkage and collapse of the wood occur in the parts which are not impregnated with the resin. In this study, 20 melamine formaldehyde treated core samples, which were taken from Yenikapı shipwrecks, were analysed with FTIR-ATR to determine the success of the impregnation.Spectra of fresh wood, waterlogged wood, and melamine formaldehyde treated wood were analysed considering wood species in order to determine significant bands which are related to melamine formaldehyde. On the spectra of melamine formaldehyde treated woods, the band was determined at ∼ 810 cm−1 which is formed due to the presence of triazine. With this gained information, FTIR analyses were done on the wood samples that were in the impregnation boxes. The band at ∼ 810 cm−1 was determined on the spectra of these samples. It showed that woods were impregnated with melamine formaldehyde and that they can be dried in order to end the process.

The Conservation of Lindow Man and Subsequent Changes

ABSTRACT Lindow Man is the name given to a body excavated from a peat bog in Cheshire in 1984. After extensive scientific examinations were complete a conservation treatment was developed and carried out using parallels drawn from the conservation of water-logged wood and bone. It was decided that soaking in polyethylene glycol (PEG) solution followed by freeze-drying offered the best prospect of success and the optimum method of polymer impregnation was determined by experiments performed on artificially-aged pig skin. Following successful conservation, Lindow Man has been exhibited in various locations and some changes of the skin colour have occurred. This has been monitored and some experiments on accelerated light-ageing carried out on a detached sample. Several areas for future research have been identified; these include the stability of PEG, the change of appearance of conserved bog body skin, and new methods of conservation.

Organosilicon compounds with various active groups as consolidants for the preservation of waterlogged archaeological wood

Abstract Waterlogged wood conservation focuses primarily on its dimensional stabilisation to prevent irreversible deformations that occur upon drying. It also aims to solve the concerns regarding wood degradation as well as its physico-mechanical properties, all of which are inextricably connected with wood hygroscopicity. Therefore, the reduction of wood hygroscopicity can provide a solution to some of the conservation problems. Due to the hydrophobising properties and the ability to cell wall bulking, a set of organosilicons with various active groups were selected to evaluate their stabilisation effect on highly degraded medieval waterlogged elm wood. Exceptionally satisfying results were obtained for (3-Mercaptopropyl)trimethoxysilane, 1,3-Bis(diethylamino)-3-propoxypropanol)-1,1,3,3-tetramethyldisiloxane and Methyltrimethoxysilane, for which the volumetric anti-shrink efficiency was around 98%, 90% and 81%, respectively. Additionally, the applied treatment resulted in a decrease of wood moisture content from 6.7% for untreated wood to 2.4–3.6% for wood treated with the above-mentioned compounds. Neither the alkoxysilanes with a long alkyl chain, nor those terminated with a highly hydrophilic pyridine ring were found effective for waterlogged wood stabilisation. It can be concluded that the organosilicon compounds with alkoxy groups and a relatively short alkyl chain or containing and additional chemical group enable to form stable bonds with wood components proved to be the most effective wood stabilisers.

Application of methyltrimethoxysilane to increase dimensional stability of waterlogged wood

Abstract Conservation of historic wooden monuments, especially regarding waterlogged archaeological wood, is a complex, long-term, multi-stage and also a quite difficult process. The main problem is poor dimensional stability of such artefacts due to a high degree of wood tissue degradation and its significant saturation with water. Exposing wood to a natural drying process causes its shrinkage, cracking and irreversible deformation due to collapse. Therefore, the first stage of maintenance of waterlogged wooden objects is to replace the water filling cell lumina and cell walls with an appropriate consolidation agent that will protect wood against shrinkage, collapse and loss of shape. Silanes have so far been used mainly as additives for wood preservatives and coatings, increasing wood hydrophobicity or decreasing its hygroscopicity. Some silanes show resistance to biotic degradation. As confirmed in scientific reports, their ability to improve dimensional stability of contemporary wood makes them a potential agent for stabilisation of archaeological wood. The aim of the research was to determine the influence of methyltrimethoxysilane (MTMOS) treatment on the dimensional stability of waterlogged elm wood excavated from the Lednica Lake in the Wielkopolska Region. Freshly taken from the lake and still completely saturated with water, elm wood samples were treated with ethanol solution of 50% MTMOS by the vacuum-pressure impregnation method. Pre- and post-treatment dimensions of wood samples were measured and anti-shrink efficiency (ASE) was calculated. ASE values of elm wood treated with MTMOS varied from 69.4% to 94.5%, depending on the state of wood degradation. In case of reference wood samples treated with polyethylene glycol, ASE ranged between 96.1% and 100%. Taking into account the improvement of wood dimensional stability obtained, the aesthetic end result of the treatment and its properties of hydrophobicity and antifungal activity, the silane MTMOS can be considered as a potential agent for conservation of waterlogged wood and seems to be worth further study.

Revisiting Conservation Treatment Methodologies for Waterlogged Archaeological Wood: An Australian Study

This article discusses a theoretical framing of a conservation research project that focuses on waterlogged archaeological wooden artefact composed of Australian tree species. Although a multitude of materials and methods have been reported on in the conservation literature, four consolidation methods for waterlogged archaeological wood are outlined. These methods have been selected due to their representativeness of the development of treatment technique within the field of waterlogged wood conservation over the past 60 years and also because of their potential applicability for the conservation of wood in an Australian context. If operating within the boundaries of best practice, conservators will select the most appropriate treatment method for the artefact by consideration of variables such as the size and mobility of the artefact, the degree of degradation of the wood, the artefacts end use, the eventual location and lastly the owner, client or custodian's requirements informing conservation outcomes. Australian conservation practice for terrestrially found archaeological wood is limited by a lack of published knowledge about the treatment of Australian wood species. This is a result of the scarcity of wooden artefact finds in the Australian archaeological record to date; this is particularly true for the finds from the pre-European contact era. It is hoped that this survey of selected conservation methods for waterlogged wood will aid in determining a treatment pathway for highly significant Australian artefact finds in the future. The paper highlights developments in conservation treatment-based research for waterlogged wood from Australia, Scandinavia, Turkey and China, with the aim of drawing together some conservation treatment methodologies that hold potential for successful application in an Australian context. It provides a useful background research setting for Australian research to come and underlying this discussion are the notions of irreversibility and re-treatability in conservation, versus the issues of long-term stability and accessibility of cultural material.

Building for the Sea Safeguarding Ashore. Brigs, Ships and Peote: A Complex Conservation

The presented work is intended to be an international overview on the most important conservative project of naval heritage. As it was immediately clear that mostly concerns ancient shipwrecks' structures which came from underwater environment and made of waterlogged wood, the analysis has therefore focused on waterlogged wood conservation and reinforcement. Based on the state of the art in the field of conservation and management of ancient ships some considerations can be made. The conservation of artefacts coming from the underwater environment has began in the mid XXth century and developed through a great deal of effort which has resulted in a strong improvement of scientific and multidisciplinary research. Case-studies are various and it is clear that conservative approaches and choices are, sometimes, in contrast: an improvement of the state of the art in this particular field is therefore actual. The considered examples concern different experiences both in historical features and in their conservative tracks. In the selection different situations were taken into account, in order to get to a proper analysis of conservation and on how methods and protocols may have evolved over the years. On one side the research dealt with the waterlogged wood, on the other the goal was establish a method applicable to a wider context. In the case of the last two structures taken into account, it was to check whether the same multi-phase and multidisciplinary approach recorded could be appropriate to achieve, even in this case, the common purpose of heritage conservation.

The Vasa experience with polyethylene glycol: A conservator's perspective

Abstract It is now fifty years since the raising of the Swedish warship Vasa , one of the first wooden shipwrecks and certainly the largest to have been conserved with polyethylene glycol (PEG). Now a standard material for waterlogged wood conservation, PEG has since been used on a number of other shipwrecks, thanks largely to the Vasa experience. As the second generation of conservators at the Vasa Museum in Stockholm, we are often asked our opinions about PEG, and whether we would still use the same materials and techniques should another ship like Vasa be raised today. What have we learnt and what would we do differently this time? In this paper, we examine the Vasa experience from the initial conservation decisions, through to the most recent research projects and examine how PEG has fared over the last fifty years. Finally, we take the lessons learned and apply them to the future, both for Vasa material and for newly found wrecks.

수침목재유물(水浸木材遺物) 보존처리(保存處理) 폐수(廢水)로부터 EDTA회수(回收)

Fe-EDTA를 함유한 수침목재유물 보존처리 폐수로부터 EDTA를 회수하고 재활용하기 위해 산 조절 침전 석출 기법을 이용하였다. EDTA는 문화재보존처리 분야에서 수침고목재의 흑화현상을 제거하는데 사용되어왔다. 수침목재유물은 오랜 기간 땅속에서 매장되어 토양의 Fe가 목재 내부의 타닌과 결합하여 흑색을 띄게 되며, 목재의 흑색을 제거하기 위해 고농도의 EDTA용액을 사용한다. 목재의 흑색은 Fe-EDTA착물이 형성되어 제거되며, EDTA는 pH 2.68이하에서 Fe와 분리되어 침전된다. 침전획득물과 실제 EDTA를 적외선분광분석기 (FT-IR)와 전계방사형 주사전자현미경(FE-SEM)를 이용하여 비교 분석하였다. 분석결과 pH조작 후의 침전획득물은 나트륨착체나 Fe-EDTA 형태의 착물형성이 아닌 순수한 EDTA로 확인되었다. 본 연구에서는 Fe-EDTA를 함유한 폐수에 HCI을 첨가하여 Fe<TEX>$^{3+}$</TEX>를 분리해 내고 강산성에서 EDTA가 석출되는 원리를 이용하여 EDTA의 재활용이 가능하다. pH control-precipitation method is used for recovery of EDTA from waste fluid of archeological waterlogged wood conservation treatment. EDTA has been used for eliminating of blacken effect in archeological waterlogged wood which was buried in the ground for long period of time. The black substance is generated by Fe<TEX>$^{3+}$</TEX> in the soil reacted with tannin in the archeological waterlogged wood. In order to remove the black substance in archeological waterlogged wood, EDTA was used. The black substance is eliminated from wood as Fe-EDTA complex are formed, and EDTA is separated and precipitated from Fe-EDTA complexes at pH 2.68 or less. The result of analysis of the precipitated products and the commercial EDTA by FT-IR and FE-SEM showed that precipitated product by pH adjusted was not a type of Fe-EDTA complex, but pure EDTA. In this study, Fe<TEX>$^{3+}$</TEX> from waste fluid of EDTA can be separated by HCl added. EDTA can be recycled by using the method of precipitation of EDTA in a strong acid.

Organic Materials from Wet Archaeological Sites: The Conservation of Waterlogged Wood

In this article attention is devoted to methods for conserva- tion of organic materials from wet archaeological sites, with specific reference to waterlogged wood. The range of organic materials which can be expected on wet sites is discussed, and three conservation methods for wood, i.e. controlled drying, the use of sugars as a bulking material and polyethylene glycol or PEG, are described. These conservation methods have been selected as being the best to apply in South Africa. The necessity to conserve water- logged wood has until recently hardly been acknowledged locally. With the introduction of maritime archaeology and the growing realization of the importance of the archaeological potential under the water surface, together with the ongoing recovery of many waterlogged organic remains during salvage operations, it has become a matter of urgency to establish an infrastructure to deal with the conservation of these materials.

Polycarboxylic acids via catalytic hydrocarboxylation of polybutadienes

Polybutadienes with various different microstructures have been hydrocarboxylated using different homogeneous catalytic systems. With [PdCl2(PPh3)2]–SnCl2 as the catalyst, high conversions of the pendant double bonds to terminal carboxylic acids are obtained and the backbone double bonds are unreactive. Using PdCl2, CuCl2 and O2 at room temperature and 1 atm (101 325 Pa) pressure a non-selective reaction occurs so that carboxylic acid groups are introduced at the backbone double bonds as well as on the terminal or internal C atoms of the pendant double bonds. The reactivity order, backbone > terminal > internal, is interpreted in terms of a generally higher stability for secondary alkyl intermediates, provided there is no chain branching at the C atom a to the point of attachment to the metal. Using sequential reactions catalysed first by [PdCl2(PPh3)2]–SnCl2 then by [PdCl2(PPh3)2] in the presence of excess PPh3, a polymer is obtained containing no double bonds, but carboxylic acid groups attached to the terminal C atoms of the pendant double bonds and to the backbone of the polymer. Gel-permeation chromatography indicates that neither chain scission nor extensive crosslinking takes place during the reaction. The use of one of the polymers for preventing the uptake of water by balsa wood is described, and evidence is presented that the polymer is not useful for the conservation of waterlogged wood.

ポリエチレングリコール（ＰＥＧ）含浸による出土木材の保存処理の改良 陽イオン界面活性剤を使用して

In the conventional polyethylene glycol (PEG) method for conservation of waterlogged wood, it becomes sometimes difficult for PEG to penetrate into wood, depending on wood species or the degree of deterioration, and the shrinkage (e.g., max. 20-30% in tangential direction) or warp of specimens occurs. In the present study, in order to maintain their dimension and mechanical strength, Akagashi (quercus acuta Thunb.) wood was treated with some cationic surfactants which are easily adsorbed on cellulose and thus lower surface tention of water. By the surfactant treatment it is expected that possible shrinkage accompanied by water evaporation can be reduced. The size of the specimens used were 3×3×1.5 (tangential×radial×longituainal in cm). They were soaked in a few percent of cationic surfactant solution, followed by immersion into PEG solution with gradual increase of its concentration. The variations of dimension and weight were monitored periodically. As the result it was found that the surfactant treatment allowed PEG to penetrate easily into waterlogged wood which is otherwise difficult to allow the conservation treatment. Furthermore, it was noticed that the shrinkage and change in shape could be minimized, and the dimensions were maintained without any significant change. In addition, by using the present treatment, one can expect that the penetration time in the PEG treatment will be shortened.

Study and Conservation of Waterlogged Wood

Study and Conservation of Waterlogged Wood

Conservation of waterlogged wood: a preliminary study ofBalanghai 5, an ancient boat of the Philippines

Conservation of waterlogged wood: a preliminary study of<i>Balanghai 5</i>, an ancient boat of the Philippines

The Conservation of Waterlogged Wood Using Sucrose

The Conservation of Waterlogged Wood Using Sucrose