Finishing oil seeds of the flax plant, already extensively grown for the production of linen. The raw oil may be used, but it cures poorly and leaves a sticky surface. Normally boiled linseed oil is used. This has been prepared beforehand by boiling with lead, in the form of lead oxide, or with manganese salts. Modern boiled oils use a lead-free metallic drier added cold, such as cobalt resinate. Old linseed oil finishes yellow with age, owing to oxidation with the air. Linseed oil was also widely used for the production of oilcloth, a waterproof covering and rainwear material, formed by coating
Oil production plant Sometimes the produced oil may be "stabilised" (a form of partial distillation) which reduces vapour pressure and sweetens "sour" crude oil by removal of hydrogen sulphide, thereby making the crude oil safer for storage and transport. The production plant is said to begin after the production wing valve on the oil well. The product from each well is piped through the choke valve, which regulates the rate of flow. The flowlines are gathered at the inlet manifold and routed into a separator, which will separate the three components. Once the oil has been separated from the gas and produced water,