Dirt, grease, old loose or flaking materials must be removed. The surface must be unhumide. Holes should be filled using a specific putty; a mixture of wooden dust and varnish. Leave the surface for drying for 24 hours. Level the surface with sandpaper and fill the surface with Axuwood. Wipe the surface with a damp cloth to remove dust. After completion of these steps, the surface will be ready for priming. To have a penetration of the varnish on the wooden surface, dilute with 10-15% (by volume) of thinner and apply 2-3 layers of varnish with respecting 5-6 hours between each layer. You can use a roll, brush or spray gun for application.