What are the different types of polishing pastes, and how to choose the right one?

As the polishing wheel rotates, a thin layer of polishing paste is evenly applied to its surface in order to remove minor irregularities on the surface of the product. Polishing paste is a paste form made by combining polishing materials such as diatomaceous earth, quartz sand, pumice, iron oxide red, Vienna lime, and chromium oxide with certain binders such as stearic acid and paraffin. Polishing pastes are generally available in three colors: white, red, and green. Depending on the material of the item to be polished, a different polishing paste should be used. White polishing paste is composed of anhydrous and high-purity calcium oxide, a small amount of magnesium oxide, and some binders. It is suitable for polishing softer metals such as aluminum, copper, and their alloys, as well as for polishing plastics. Red polishing paste is made up of iron oxide red (Fe2O3) powder along with some binders. Fe2O3 has moderate hardness, which makes it suitable for polishing steel products and giving them a polished finish after grinding. Green polishing paste – its abrasive is chromium oxide, a hard and sharp powder suitable for polishing cemented carbide steel, chrome plating, and stainless steel

There are mainly three types of polishing pastes: green polishing paste, white polishing paste, and yellow polishing paste. Green polishing paste is primarily composed of chromium oxide; it is also known as lead oxide polishing paste. This type of polishing paste has good abrasiveness and is mainly used for polishing chromium and stainless steel. It is not applicable to metals such as steel and aluminum. White polishing paste is primarily made from polishing lime. (Polishing lime is mainly composed of calcium oxide and magnesium oxide.) This type of polishing paste has moderate performance and is most suitable for polishing metals such as copper, brass, nickel, and aluminum. Due to the low stearic acid content in its composition, white polishing paste tends to weather when exposed to air; it should be stored properly after use. A simple way to do this is to place it in a plastic bag and seal it tightly. Butter polishing paste is primarily composed of iron oxide; it is mainly used for giving a shiny finish to steel parts after grinding, as well as for rough polishing of copper and its alloys.