The determination of the upper surface characteristics of the some wood types modified with natural preservatives

Tannin, which protects the tree in its natural environment, is found abundantly in the fruit and leaves of the walnut tree, which is widely grown in our country. In this study, it is aimed to determine the effect of walnut tannin used in the wood preservation on the upper surface characteristics of the wood. It was aimed to raise the economic value and increase common usage areas of the walnut tannin with the help of the data obtained as the result of the study. For this purpose, walnut tannin was diffused through Scotch pine (Pinus sylvetsris L.) and walnut (Juglans regia L.) tree test pieces with a brush, and a protective layer was formed on the surface with water-based varnish and polyurethane varnish, and the surface hardness and surface gloss values of this layer were evaluated. Before the measurements were conducted, the test pieces were randomly selected from the first-class timbers according to TS 2470. (1976) standards, and surface hardness and brightness measurements were carried out according to TS 2479., (1976) and TS 6956 EN ISO 4287 (2004) standards. These measurement procedures include pre- and post-tannin measurements and pre- and post-varnish measurements. The application of the tannin on the wood surface was conducted by applying three layers (parallel to the grain - vertical to the grain and again parallel to the grain) with a brush and waiting for two hours between layers for the tannin to dry. According to the test results obtained at the end of these procedures, the highest surface hardness values were observed respectively in walnut + control + polyurethane varnished (100.4 N / mm2), walnut + tannin + polyurethane varnished (98,4 N / mm2) and Scotch pine + control + polyurethane varnished ( 93.2 N/mm2) samples. The lowest surface hardness values are observed respectively in scotch pine + control + water-based varnish (36.2 N / mm2), scotch pine + tannin + water-based varnish (38.4 N / mm2) and walnut + tannin + water-based varnish (42.6). N/mm2) samples. For the samples with varnish application, the highest brightness value parallel to the grain were found as; Scotch pine + control + polyurethane varnished (91.34 L), the lowest value was found in walnut + control + water-based varnished sample (52.84 L). The highest brightness value parallel to the grain in varnished samples were observed in; Scotch pine + control + polyurethane varnished (100.98 L), the lowest was in walnut + tannin + polyurethane varnished (73.27 L) samples. The measured values were observed to be quite high in the control samples without tannin application for surface hardness and brightness values. It was observed that the varnish choice was more active in terms of surface hardness and brightness values. According to the tree type used in the experiment; while the brightness value of polyurethane varnished Scotch pine was observed to be higher than walnut, the surface hardness value of walnut wood was higher in terms of hardness, and the percentage (%) change was determined to be higher in Scotch pine according to control samples.