Comparison of Selected Properties of Shellac Varnish for Restoration and Polyurethane Varnish for Reconstruction of Historical Artefacts
Source abstract
Abstract
At present, many historical artefacts and furniture are only reconstructed and not restored. They are preserved in terms of material reparation, but their historical value decreases significantly. This work is focused on the comparison of the resistance of high-gloss polyurethane varnish with traditional shellac varnish. The varnishes were applied to oak wood and exposed to interior artificial accelerated ageing in Xenotest. Before and after ageing, cold liquid-resistance tests were performed on the tested specimens and gloss, colour, and adhesion were also evaluated. The structures of the surfaces were also analysed using a confocal laser scanning microscope. As expected, polyurethane varnish was much more durable than shellac varnish. Interestingly, shellac varnish was fairly resistant to water at the beginning, but this resistance was greatly reduced after artificial accelerated ageing. This illustrates the importance of sheltering the shellac treated artefacts in stable temperature-humidity conditions with the least possible effect of solar radiation.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Cultural Heritage Materials Analysis · Building materials and conservation · Conservation Techniques and Studies
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Department of Wood Products and Wood Constructions, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Prague 165 21, Czech Republic
Funding
Advanced research supporting the forestry and wood-processing sector’s adaptation to global change and the 4th industrial revolution
References (43)
Show source-provided references
1. Rivers, S., and Umney, N. (2007). Conservation of Furniture, Routledge.10.4324/9780080524641 ↗
2. Brandi, C. (2000). Teoria del Restauro, Tichá Byzanc. (In Czech).
3. Losos, L. (2013). Historický Nábytek: Konstrukce, Údržba, Restaurování, Grada. [1st ed.]. (In Czech).
4. An integrated approach to the conservation of a wooden sculpture representing Saint Joseph by the workshop of Ignaz Günther (1727–1775): Analysis, laser cleaning and 3D documentation10.1016/j.culher.2015.07.004 ↗
5. Shellac-Structure, Characteristics & Modification10.14429/dsj.33.6181 ↗
6. Formation of shellac succinate having improved enteric film properties through dry media reaction10.1016/j.ejpb.2008.03.002 ↗
7. Pharmaceutical applications of shellac: Moisture-protective and taste-masking coatings and extended-release matrix tablets10.1081/DDC-120024188 ↗
8. Effect of alkali treatment on properties of native shellac and stability of hydrolyzed shellac10.1081/PDT-35897 ↗
9. Dependence of vibrational properties of wood on varnishing during its drying process in violin manufacturing
10. The study of colour changes of chosen species of wood from Southeast Asia caused by transparent coatings and exposure to sunlight
11. Studies on the loss of gloss of shellac and polyurethane finishes exposed to UV
12. Preparation and Characterisation of Cellulose-Shellac Biocomposites10.15376/biores.12.1.1943-1959 ↗
13. Efficacy of shellac-based varnishes for protection of wood against termite, borer and fungal attack10.1007/s13196-015-0138-2 ↗
14. Possibilities for improvement of moisture and strength properties of decayed spruce wood with natural resins
15. Permeability of Shellac Coatings to Gases and Water Vapor10.1021/jf00005a001 ↗
16. Studies on moisture resistance of a traditional and a commercial finish on mango wood at elevated temperature and high relative humidity
17. Studies on effect of coat thickness on the moisture uptake by a hardwood substrate
18. Degradation of lac with storage and a simple method to check the same10.1108/03699420910973297 ↗
19. Cook, W. (2015). The Complete Guide to Repairing & Restoring Furniture, Southwater.
20. Lyons, R.A. (2000). Restoring Antique Furniture: A Complete Guide, Dover Publications.
21. Wagenführ, R. (2002). Dřevo—Obrazový Lexikon, GRADA Publishing.
22. British Standards Institution (BSI) (2016). EN 350:2016 Durability of Wood and Wood-Based Products—Testing and Classification of the Durability to Biological Agents of Wood and Wood-Based Materials, European Committee for Standardization.
23. Miles, H. (2002). Meubels Restaureren, Rebo Productions.
24. Shellac/nanoparticles dispersions as protective materials for wood10.1007/s00339-016-0577-7 ↗
25. Surface treatments of wood by chemically modified shellac10.1179/1743294412Y.0000000069 ↗
26. The National Standards Authority of Ireland (NSAI) (2013). EN 12720+A1:2013—Furniture—Assessment of Surface Resistance to Cold Liquids, European Committee for Standardization.
27. Molecular changes during natural biopolymer ageing—The case of shellac10.1016/j.polymdegradstab.2012.03.024 ↗
28. Evaluation of aesthetic durability of waterborne polyurethane coatings applied on wood for interior applications10.1016/j.porgcoat.2011.03.013 ↗
29. (2006). EN 15187:2006 Furniture—Assessment of the Effect of Light Exposure, European Committee for Standardization.
30. (2014). EN ISO 16474-2:2014—Paints and Varnishes—Methods of Exposure to Laboratory Light Sources—Part 2: Xenon-Arc Lamps, European Committee for Standardization.
31. (2016). D2244-16:2016—Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates, ASTM International.
32. (2015). EN ISO 2813:2015—Paints and Varnishes—Determination of Gloss Value at 20°, 60° and 85°, European Committee for Standardization.
33. (2002). D4541-02:2002 Standard Test Method for Pull-off Strength of Coatings Using Portable Adhesion Testers, ASTM International.
34. (2013). EN ISO 15184:2013—Paints and Varnishes—Determination of Film Hardness by Pencil Test, European Committee for Standardization.
35. Structural changes in wood under artificial UV light irradiation determined by FTIR Spectroscopy and color measurements—A brief review
36. A spectrocolorimetric study on the effect of ultraviolet irradiation of four tropical hardwoods10.1016/j.biortech.2003.10.035 ↗
37. Wood surface discolouration due to simulated indoor sunlight exposure10.1007/s00107-007-0201-9 ↗
38. Study of the effect of photo-irradiation on the surface chemistry of wood10.1016/j.polymdegradstab.2005.02.009 ↗
39. Polyurethane coatings on hardwood and softwood surfaces: Their resistance to household liquids as an educational case study10.15376/biores.12.3.5867-5877 ↗
40. Scavenge moisture and cut pinholes in a trice
41. The effects of surface roughness on adhesion strength of coated ash (Fraxinus excelsior L.) and Birch (Betula L.) wood
42. Influence of surface roughness and species on bond strength between the wood and the finish
43. A Shellac derivative in thermoset coatings10.1007/s11998-010-9240-y ↗