Equilibrium Moisture Content of Wood in Southwest Islands, Japan VI : Variation of moisture content of coated wood through the year

In this work, the variations of actual moisture content (M. C.) of various kinds of coated wood specimens were investigated from April 1982 to March 1983. Kiln-dried Melapi was used for the test material, the differences in the variation of M. C. values through the year of the coated specimens by kind of coating material, thickness of the test specimens and the place where the test specimens were tested were examined. The values of yearly mean actual M. C. of 20mm thick coated specimens in the laboratory become in the order of double-face coated specimens, single-face coated specimens, and non coated specimens for all coating materials. These M. C. values of coated specimens decrease in the order of lacquer enamel > acryl lacquer, oil varnish > polyurethane > kuro roiro-urushi. And these M. C. values of various thick (5-40mm) polyurethane coated and non coated specimens in the laboratory decrease as the test specimen bocomes thicker. Furthermore, these M. C. values of 20mm thick polyurethane coated specimens show the highest in the shelter, the second in the laboratory, the third in the dwelling, and the lowest in the hotel.