Using nanocellulose mixtures for the wood stabilisation of a Lilienthal glider

• Consolidating the willow wood of a Lilienthal glider with cellulose. • Enhancing deteriorated wood with Nanocellulose and Methyl cellulose. • Reinforcing decayed wood using low-viscosity Nanocellulose mixtures. • Strengthening wooden components with celluloses. • The conservation of a Lilienthal glider at Deutsches Museum Munich. • Natural cellulose polymers as alternative to synthetic resins. At the end of the 19th century, Otto Lilienthal (1848–1896) built humanity’s first airplanes. The Deutsches Museum Munich owns Lilienthal’s personal glider since 1904 and investigates preservation methods since the 1980s. The wooden fragments were severely damaged by the so called ‘woodworm’. Therefore, the frame of the glider needed to be stabilised in order to preserve it for future handling during conservation and exhibition. The choice of materials followed methods used at the University of the Arts Bern in Switzerland. In particular, the approach to reinforce Methyl cellulose with Nanocellulose was further investigated for the purpose of stabilising the infested wood of the glider. Pre – tests with celluloses showed that they meet the requirements of the conservation concept. Therefore, an object-related laboratory testing series was carried out in collaboration with the Leibniz Institute for Materials Engineering - IWT in Bremen, Germany. The laboratory results enabled the celluloses to be applied with respective to individual situations of the wooden fragments of the glider in 2024. They proved to be practical as wood stabilising agents, and the characteristic thixotropy of Nanocellulose was beneficial while using the mixtures on the fragments of the glider. The chemical properties of celluloses, their almost unchanged surface appearance after drying, and the non-toxic application of this natural polymer make these mixtures an attractive and sustainable wood stabilisation agent for the conservation of historic wooden artefacts.