The objective of this project was to develop an economically, technically and environmentally viable transparent coating that will provide long-term weather protection without masking the natural colour and texture of wood. The project focused on: 1). pre-treatments to prevent degradation of the underlying wood by light wavelengths penetrating transparent coatings; and 2). biocide combinations to extend duration of resistance to black stain fungi. The work done and the reports produced from this work are summarized in this report. Based on a critical review of the literature and the work done in this project over the past six years, the following recommendations can be made to optimize the performance of water-based transparent coatings on wood in exterior vertical applications.
Use heartwood faces
Round all corners
Sand even fresh wood
Pre-treat with an effective biocide combination and a visible light protection system
Selection of a coating virtually opaque to UV light with an optimum combination of water resistance and vapour permeability with water-sheeting surface properties
Coating application to a thickness of 60 microns (2.4 mils).