Chemists create turpentine by distilling the resin extracted from pine trees. Turpentine works as a solvent, breaking down the molecular compounds found in the paint's oil base. Although often used as a general paint thinner during application, turpentine effectively removes the oils stored in a brush's fibers when applied in higher concentrations. Saturate the brush's hairs in a container of undiluted turpentine solution and rinse with water to effectively clean a brush for future use.
White spirits, also known as the Stoddard Solvent or mineral spirits, use organically occurring hydrocarbon molecules to disintegrate oil-based solutions. White spirits specifically manufactured for oil paint removal contain lightly concentrated distilled petroleum. Soak the brush's bristles in a small amount of white spirits in a well-ventilated environment to prevent harmful inhalation. Some artists develop allergies to the air particles released by such solvents. Most art suppliers offer more refined, odorless mineral spirits specifically composed for oil-paint applications.
Scientists and chefs often extract walnut oil from Persian walnuts for nutritional and cooking purposes. However, walnut oil works extremely well at removing oil solutions from paint brushes, especially paint that has solidified due to long term exposure to air. Walnut oil does not release harmful vapors or odors. Wash brushes used with oil-based solutions in a small container of paint-purpose walnut oil. Thoroughly rinse the brush's hairs with an adequate amount of water to prevent yellow stains on bristles or canvases.
Dish detergent and other forms of soap counteract the greasy, adhesive qualities of the bases of oil paints. When combined with water, soap forms the molecular bridge for hydrocarbon compounds to break down the oils stored within the bristles of the paint brush. Stir the hairs of the brush in a small, highly concentrated portion of dish detergent, rinse with water, and wipe with a clean towel. Repeat these steps methodically until clear of paint.