Investigation of the effect to on performance of the varnish layer of the thermal modification and UV aging process applied some the wood species used in yachts and boat furniture

The aim of this study is to determine the impact of heat treatment (ThermoWood) and accelerated aging (UV) on the different varnish layers applied to the wood materials which are commonly used in the yacht and boat manufacturing sector and the furniture and decoration industry. For this purpose; the ach grown in Turkey (Fraxinus angustifolia Vahl.), as a kind of domestic one and, ıroko (Chlorophora excelsa) and also exotic wood species were determined as the test material. The heart treatment was applied on the experiment samples for 1,5 hours at 190°C and for 2 hours at 212°C. Then, they were exposed to QUV Accelerated Weathering Tester device, that UV-B 313 EL-type flourescent lamps were used as the varnish film layer, for 144, 288, 432 and 576 hours (ISO 11507 A) as the single and double component water-based varnishes and the double component acrylic and polyurethane varnishes were applied. After each the accelerated aging; the values of color change (a*, b*, L* and ΔE*) (ASTM D 2244-3), oscillating hardness (ANS / ISO 1522), glossiness as parallel with the fibres and perpendicular to them (ISO 2813), surface roughness (Ra*) (ISO 4287), surface adhesion resistance (ASTM D 4541) were investigated. Consequently, a decrease was determined in Ra*, Rq*, Rz* roughness values with b*, L*, ΔE*, glossiness while an increase was determined in values of a*, surface hardness, adhesion at the materials which were exposed to the heat treatment at 190ºC for 1,5 hours. A decrease in the values of a*, b*, L*, ΔE*, glossiness, and the adhesion was determined, and an increase was determined in the surface hardness at the materials which were exposed to the heart treatment at 212°C for 2 hours. It is considered that the high value-added and eco-friendly products can be revealed with the use of thermowood wood and water based varnishes in the manufacture of yacht and boat furniture.