- TYPES OF OIL:
Drying oil:
Drying oils are fatty oils of vegetable matter that can react chemically with the oxygen in the air to solidify and become dry to touch. Drying oils thicken and harden into a paint film over two to five day periods.
Drying oils is both the binder and the vehicle for the pigments that are used in oil painting.
Some example are
1.Raw drying oil : Linseed oil, poppy seed oil, walnuts oil, safflower oil, sunflower oil,
2. Processed oils : Sun thickened oil, stand oil
Drying oils dry and harden in normal temperature because these oils contain linolenic acid is found . this acid combined with oxygen in the air. Linolenic acid is found in linseed oil. this acid combine with oxygen rather than linoleic acid and provides strong film and good drying speed. linoleic acid is found in poppy oil.
Linseed oil contains 60% of Linolenic acid and 10-20% of Linoleic acid. Poppy oil contains 0% of Linolenic acid and 70% of linoleic acid. Walnuts oil contains 10-15% of Linolenic acid and 60% of Linoleic acid.
semi drying oil:
A non drying oil is an oil which does not harden when it is exposed to air. Non drying oils and vegetable such as peanut oil and cottonseed oil , that resembles animal fats and because they do not oxidize naturally and harden are unsuitable as a binder for paint.
Oils with an iodine number of less than 115 are consider non drying.
Example are almond oil, Babassu oil, coconut oil, Nahar oil, Olive oil, Macadamia oil
Mineral oil:
Crude oil or petroleum and its refined components, collectively termed petrochemicals are resources in the modern economy. crude oil originates from ancient fossilized organic material such as zooplankton and algae, which geochemical processes convert into oil. it is classified as "mineral oil" is instead of as "organic oil" because its organic origin is remote and because and sands. Mineral oil also refers to several specific distillates of crude oil.
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