Linseed oil is available in every grocery store, but is not a preferred commodity for many people. The very reason it's available at stores is for its utility value. There are multiple benefits of this oil―from painting to wood finish, and from varnishes to inks. Flaxseed oil, as it is more commonly known, is a natural vegetable oil collected from flax that are crushed between heavy steel rollers. The crushed paste is then heated with steamers, and made to pass through a screw expeller or hydraulic press which separates the rich oil from the solid paste. The solid by-product is a high protein substance that is used as food for farm animals. The obtained oil is later processed or heated and is known as boiled linseed oil.
Linseed oil is essentially a drying oil as it polymerizes into a solid form. Due to this quality, it is used extensively for many chemicals and furnishing works.
Wood Finish: Due to its polymer-forming properties, linseed oil is used to polish wood furniture. Traditionally, raw and cold linseed oil was used because it was slow drying, but this proved to be time consuming. The boiled oil dries quickly and hence makes the polishing process less time-consuming. It also makes the furniture resistant to dents and scratches and also adds a shiny look to the wood. Sadly, with the rise of synthetic chemicals, this practice is gradually declining.
Paint Binding: Boiled linseed oil is used in oil paintings. It is mixed with basic paint, thinner, and a dryer. It aids fluidity that allows the formation of levels when applied to the surface. It also makes the paint more transparent and glossy. After the paint is applied, the thinner evaporates, leaving the oil to react with the oxygen, which results in the formation of a tough film that gives a shiny appearance.
Putty: Putty is like a special cement that resembles clay or dough and is used in domestic construction. It is used to repair the sealant or fillers. If it is hard or stiff, a little amount of boiled linseed oil can impart fluidity, making it easier to apply. It also adds glaze which is the desired look for caulking areas in furniture.
Other Uses: Boiled linseed oil is used extensively in wood preservation processes, varnishes, enamels, resins, leather treatments, oilcloth, concrete, printing inks, liniments, soaps, industrial lubricants, animal feeds, caulking compounds, earthen floors, polishes, textiles, animal care products, and more.
As a precautionary measure, this oil should not be used for consumption unless it is mentioned as "food grade". Only raw, unprocessed, and natural linseed oil should be consumed as it is a great nutritional supplement containing essential omega-3 essential fatty acids that reduce the risk of heart diseases.
Boiled linseed oil cannot be used by itself, but it is an important ingredient as a raw material for many products that are extensively used in our everyday lives.