What Does Drying Oil Mean?
Drying oil is fatty vegetable oil that is capable of chemically reacting with oxygen present in the air. Eventually, the oil hardens and dries. These oils serve as the major component of varnishes, oil paints and other anti-corrosion coatings.
Typical examples of drying oils include:
- Poppy seed oil
- Perilla oil
- Linseed oil
- Tung oil
- Walnut oil
Corrosionpedia Explains Drying Oil
Drying oils have varying consistencies and drying rates, so the methods of processing drying oils differ. In general, the hardening or oil curing results from the process of auto oxidation – the adding of oxygen into organic compounds. This starts with the insertion of oxygen molecules to the bonds of hydrogen and carbons. In this, changes in oil films occur – the film that is formed becomes heavier as it soaks up oxygen. For instance, linseed oil increases in weight by as much as 17%.
As the drying oil undergoes aging, more changes take place. The bonds of ester present in the oil go through hydrolysis, which releases fatty acids. In the case of paints, these fatty acids act in response to metals, generating metal carboxylates that aid in corrosion protection.
In industries where metals are most present, oil-based formulas or coatings play a vital role in protecting the metal and preventing the formation of rust, making it an essential component in the manufacturing of industrial paints and coating.