Surface Preparation of Wood for Application of Waterborne Coatings
Year after year, water-based coatings gain market share due to new regulations on volatile organic compound emissions and voluntary certification programs. Work still has to be done on wood surface preparation, however, for water-based finishes to become truly reliable. In this research, water-based and solvent-based coatings were apllied to edge-glued panels of yellow birch (Betula elleghaniensis Brit.). Sandpaper grits from 150 to 280 were used to prepare wood surfaces prior to coating application. A first series of specimens was prepared with a wiping stain and a second series with a spray stain. Contact angle measurements showed that surface preparation-more precisely the sandpaper grit-strongly affects water wettability and hence coating adhesion. Adhesion was found to change with the contact angle of the water. It was found that using a 150-grit sandpaper leads to unfilled wood cavaties, high contact angles, and poor coating adhesion. At the opposite end of the range, using a 180-grit sand paper leads to good wetting and good adhesion. In our tests, surface preparation had no found to affect the color of the specimens.
Tidak ada salinan data
Tidak tersedia versi lain