This study aims to evaluate the adhesion resistance of water-based single-component varnish layers to wood surfaces by incorporating sodium borate in varying proportions. The research was conducted using specimens obtained from wood materials of Scots pine (Pinus sylvestris L.), Turkish fir (Abies bornmülleriana Mattf.), Sessile oak (Quercus petraea L.), and Oriental beech (Fagus orientalis L.). These specimens were impregnated with sodium borate solution at concentrations of 1.5% and 2.5%. After the impregnation process, water-based varnish formulations containing different proportions of sodium borate (1.5% and 2.5%) were prepared. Once the varnish layers were fully dry, an adhesion test was conducted according to ASTM-D 4541-02 standards. As a general conclusion, it was found that the modified varnish and impregnation processes resulted in the highest efficiency with beech and oak wood materials, while the impact of the sodium borate was more limited on scots pine and fir wood materials.