Tung oil tung oil is the only drying oil that will polymerize 100% (completely harden). Linseed oil, for example, never completely hardens. Since tung oil has become popular as an environmentally friendly wood finish, some products labelled as "tung oil" are actually blends containing other oils, varnishes, solvents, or chemical driers, and may even containing no tung oil at all Products labeled "Danish oil" may be tung oil or they may be polymerized linseed oil. The product packaging will usually clearly state if it is pure tung oil. Heating tung oil to about in an oxygen-free environment will substantially increase the viscosity
Essential oil Essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (defined as "the tendency of a substance to vaporize") aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetherolea, or simply as the oil of the plant from which they were extracted, such as oil of clove. An essential oil is "essential" in the sense that it contains the "essence of" the plant's fragrance—the characteristic fragrance of the plant from which it is derived. The term essential used here does not mean indispensable as with the terms essential amino acid or essential fatty