Oxalic acid is a relatively strong carboxylic acid produced by the oxidation of carbohydrates or glucose with the help of air or nitric acid and vanadium pentoxide.
In the metal industry oxalic acid (C2O2(OH)2) is used in two types of processes. In one of the processes oxalic acid is used to form a durable metallic oxalate layer, which is done by immersion in a bath of oxalic acid and activators, or by an anodizing coating on aluminum. Oxalic acid is also used to clean metal surfaces.
The product can also be used to remove rust stains (flight rust) that can get caught in the paint on the cars during the winter. Oxalic acid is a highly effective detergent for washing boats as it easily dissolves all impurities. It is also used to bleach darkened objects of oak.
Oxalic acid is also available as a solution.