A reliable artificial weathering test for wood coatings

Accelerated weathering plays an important part in the development of new finishing systems. But there is no standardised method in existance which is applicable to the wood surface. This study has been conducted at the request of CEN/TC 139/WG2 in order to develop an accelerated weathering method for wood finishes. The development of the test itself had to comply with an economic criterion - to wit, the use of a device that is accessible to small and medium-sized companies. This is why the studies have been directed at cycles using fluorescent lights. Based on the experience of the different partners, several artificial weathering cycles have been tested on a limited number of finishing systems, in tandem with natural weathering tests carried out at several sites in Europe. On completion of these tests, one cycle was singled out, and re-tested by several partners in order to assess its reproducibility, which was considered good, even though different sources of variations were identified. The definiton and respect of a strict testing procedure should allow for the reduction of these variations. The studies have been pursued to refine the method by broadening, in particular, the number of finishes and wood surfaces used. At the end of this research project, a standard proposal has been drawn up and presented to the CEN/TC 139/WG2.