Rough cut lumber sells for a lower price than traditionally cut lumber. However, this lumber lacks finish and is more susceptible to damage from weather and water. To use rough cut lumber as traditionally cut lumber, you must apply appropriate finish and varnish. Finish and varnish seals lumber and protects it from water. Once you have finished and varnished lumber, you can use it in the same fashion you would use commercial lumber.
Place the piece of rough-cut wood on a level table. Apply a 100-grit sandpaper to a power sander. Sand the entire surface of the lumber.
Clean the dust off the wood using a clean cloth.
Stain the wood. Apply the wood stain using a paint brush. Use a clean towel to wipe off excess wood stain. Allow the stain to dry for several hours, turn the wood over and apply the stain on the other side. Allow it to dry for several hours.
Sand the wood using a 300-grit sandpaper. Wipe the wood with a clean cloth.
Apply a wood varnish to the wood using a paint brush. Allow the varnish to dry for eight to 12 hours. Sand the wood with 300-grit sandpaper and wipe off the dust with a clean cloth. Apply another coat of varnish and allow it to dry for eight to 12 hours. Apply a third coat of varnish.
Repeat this process for any remaining pieces of wood.