A pine tar and linseed oil finish combines the dark water-repellent character of tar with the spreading and penetrating qualities of oil, making it useful for exterior timber and rustic craft.
Pine tar and linseed oil are often paired because they solve different problems. Tar brings colour, smell, weather resistance, and a traditional preservative character. Linseed oil helps the mixture spread and can carry the finish into the surface of the wood. The result is usually easier to brush than thick tar alone.
Mix only small test amounts until the finish behaves the way the project needs. More oil usually makes the mixture easier to spread and less tar-heavy, while more tar makes it darker, smellier, and more strongly traditional. The surface should absorb the finish and dry down rather than remain greasy or wet.
Linseed oil brings its own handling concerns. Oily rags should not be crumpled and left in a pile because they can heat as they dry. Lay them flat in a safe ventilated place or follow the disposal advice for the exact products used. The finish itself belongs mainly on exterior or workshop timber, not food-contact surfaces.