The paper presents results of mycological tests and accelerated ageing tests for 13 commercially available decorative coatings in relation to costs of their purchase. Mycological tests with the use of A. niger showed that only four preparations protect spruce wood against attack of the test fungus. None of the coatings was resistant to the destructive effect of UV radiation. Testing results of resistance against A. niger attack and accelerated ageing were compared relative to purchase costs of the applied preparations. It was found that the most advantageous preparations were those with medium efficacy and of low prices. However, for the comprehensive economic analysis of the application of tested decorative coatings it is required to consider costs of coating application and surface renovation.
The article compares two different testing methods of color changes of wood coatings with varying pigment content and varying surface quality before finishing. For both Xenotest as well as Exterior testing method were set up same conditions of wood surface and all samples were coated by the same amount of paint in three layers. Three different shades of paints were tested and then compared to reference sample without any finishing paint. We also tested influence of girt size to divergence of methods by using two different sizes of abrasives for preparation of finishing. Xenotest method is faster and has only slight differences in pattern of changes in comparison to exterior method but only in case of pigment paints. When transparent finishing pattes of changes were compared differences of methods were increasing while surface quality had very significant influence to color changes in case of Xenotest. To compare and predict quality of paint systems is more suitable to use faster Xenostest but on the other hand for obtaining exact values of color changes long term exterior tests are needed.